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1Project Number: MQP-DGW-6740

THE EFFECTSOF CONCERT HALL ACOUSTICS

ON VOCAL PERFORMANCE

A Major Qualifying Project

submitted to the Faculty

of

WORCESTER POLYTECHNIC INSTITUTE

in partial fulfillment of the requirements for the

Degree of Bachelor of Science

by

____________________Thomas M. Guyette

Date: February 29, 1996

Approved:

__________________________________Professor Douglas Weeks, Project Advisor

2

Abstract-The exploration of the effects of concert hall acoustics on musical performance is one of the most elu-

sive areas of acoustical research. To expand the body of knowledge in this field, volunteer professional

and amateur singers were placed in a Digital Signal Processing (DSP) based variable acoustical envi-

ronment in an anechoic chamber. Recordings were made of thirteen content-identical performances in

ten different acoustical settings. A survey of overall impressions was administered to each singer after

every performance. The recordings were later analyzed by a panel of musicians. Analysis of the sur-

veys revealed that although musicians are often very aware of their environment, they do not necessarily

know how it affects their performance and mindset. Hypotheses about singers' needs in a performance

environment are presented, along with a number of recommendations for future research in the field.

3

Preface and Acknowledgments-

This report contains the background and procedure used in determining the effects of concert hall acous-

tics on the performance of a musician; more specifically, a singer. It includes a detailed description of

the procedure and equipment used to create an artificial acoustical environment within an anechoic

chamber, describes the recording and analysis techniques used to formulate conclusions from the perfor-

mance data, and offers suggestions for future research in the field.

My thanks goes to Professors Richard Campbell and William Michalson for their patience and indul-

gence regarding another concurrent project. Also of note was the sage advice and guidance of David

Griesinger of Lexicon Corporation, who recommended several measurement techniques, explained in

detail how the Lexicon CP1 works, and took time out of an especially busy day to encourage me.

Special thanks should also be given to Bose Corporation, of Framingham Massachusetts, for the gener-

ous contribution of equipment and space for conducting the experiment. My gratitude goes especially to

Doug Kramer, who manages the anechoic chamber, Charlie Barker, who manages the equipment, and

Richard Saffran, who manages to always be around when he is needed.

This research project would not have been possible without the time and work donated by seven terrific

musicians: Erica Curran, who played the recorded accompaniment for "America The Beautiful"; Ray

Bauwens, who tested the chamber in its initial stages of design and participated in the experiment; Jean-

Pierre Trevisani and Wendy Manas, who performed in the finalized set of environments; Rebecca

O'Brien and Christina Freeman, who performed in the experiment and analyzed the performances of

other musicians; and Doctor Douglas Weeks of the WPI Humanities and Arts Department, who advised

the project and was on the panel of objective listeners.

4

Table of Contents- Page

Abstract ii

Preface and Acknowledgments iii

Table of Contents iv

Introduction 1

Literature Review 4

THE SCIENCE OF ACOUSTICS 4

HISTORY OF ACOUSTICS 5

Reverberation Time 5

Frequency Characteristics 7

Sound Distribution 7

Early Reflections 7

Echo 8

Isolation 9

CURRENT RESEARCH IN ACOUSTICS 9

THE CUTTING EDGE IN ACOUSTICS RESEARCH 14

Experimental Procedure 15

GOALS 15

METHOD 15

Subjects 15

Music 17

Equipment 18

Environments 21

Procedure 22

5(Table of Contents, Continued) Page

Analysis of Data 24

METHOD OF ANALYSIS 24

ANALYSIS, PART ONE: ENVIRONMENT BY ENVIRONMENT 26

Environment 1: "Standard" 26

Environment 2: "High Enhanced" 32

Environment 3: "Most Live" 37

Environment 4: "High Inhibited" 41

Environment 5: "Less Presence" 46

Environment 6: "Anechoic" 50

Environment 7: "Fan Room" 55

Environment 8: "No Sides" 60

Environment 9: "Reversed" 64

Environment 10: "Sides Only" 67

ANALYSIS, PART TWO: PERFORMER BY PERFORMER 71

Performer 1: RB 73

Performer 2: RO 82

Performer 3: WM (partial data) 91

Conclusion 95

6(Table of Contents, Continued) Page

For Future Research 100

EXPERIMENTAL METHOD 100

Subjects 100

Equipment 101

Procedure 104

Questionnaires 105

ANALYSIS 107

BUDGET 108

NEW QUESTIONS 109

Works Cited 114

Appendix 1 - Acoustical Measurements and Standards 115

Appendix 2 - Letter of Invitation 116

Appendix 3 - Equipment List 117

Appendix 4 - Chamber Settings 118

Appendix 5 - Script for Introduction to the Artificial Acoustical Environment 120

Appendix 6 - Performance Session Guidesheet [Reduced to 90% original size] 122

Appendix 7 - Questionnaire 123

Appendix 8 - Performance Evaluation Sheet 125

Appendix 9 - Revised Questionnaire 128

Appendix 10 - Revised Performance Evaluation Sheet 130

Appendix 11 - Budget For Future Projects 131

7

Introduction-Since the birth of the science of concert hall acoustics, there has been a schism between the engineering

and musical communities on the topic. Traditionally, engineers designed halls, often with unplanned

acoustical properties, and musicians performed in them. There was very little communication between

the two groups. Thankfully, within the past thirty years, the intangible line separating musicians and

acousticians has been fading. Unfortunately, despite this newfound cooperation, the subdiscipline of

hall acoustics which requires the most cooperation between the two groups--the study of the effects of

acoustics on performance--has not advanced as dramatically as the rest of the field. More research is

needed in this area so that the distance between acousticians and musicians can be reduced further.

The first experiments in subjective room acoustics took place in the twentieth century, by W.C. Sabine

in the 1920s, and Leo Beranek, Manfred Schroeder, and others in the 1960s. These experiments were

extremely innovative in their equipment and experimental technique, and broke new ground in trying to

determine what concert halls audiences preferred. From these successful experiments grew a new

branch of acoustical study: subjective impressions of concert halls.

Subsequent research in this field was not limited to determining which halls audiences preferred. In-

stead, experiments were designed to determine the specific characteristics that made the halls preferable.

That is, they attempted to quantify listeners' preferences.

These experiments were instrumental in understanding the preferences of audiences for certain measur-

able acoustical characteristics. Even more importantly, they employed revolutionary techniques in con-

cert hall measurement. As better measurement techniques were created, listener-based experiments be-

came more reliable; And, as more listener-based experiments were done, more hall measurement

8techniques were developed. The process fed upon itself. However, despite the importance of these

studies, they fell short in that they left one important piece of information untouched: the preferences of

the performer.

Subjective impression experiments showed conclusively that audiences have preferences for certain hall

acoustical characteristics. It would be reasonable to assume that musicians must have equally strong--or

stronger--preferences, because the singer, unlike the audience, has an active feedback relationship to the

hall. The musician performs, listens to the result, adjusts, listens again, adjusts, and so on. Audiences

need only listen and enjoy. Thus it would seem logical that the musician, rather than the passive lis-

tener, should be the focus of acoustical preference experimentation. Despite this, upon reviewing cur-

rent acoustical literature, one sees that very little is known about the musician's interaction with his

acoustical environment. The literature review for this paper contains a single paper on the topic. And

that paper was recent enough that the data had not fully been processed at the time of publication.

The primary goal of this project, then, is to fill the gaps in the literature on the topic of the effects of

concert hall acoustics on the musician. The focus of the experiment will be singers, for reasons which

are discussed in the body of the paper. The information contained herein should benefit acousticians

and musicians equally. Acousticians designing halls will now be able to consider the musicians who

will be performing in them, and will be able to design with those musicians' needs clearly in mind. Mu-

sicians performing in these halls will be able to put forth their best performances, because they will not

have to worry about problems in support, sound quality, and delivery.

In the past, probably the single largest limiting factor in the determination of the effects of hall acoustics

on the performer was a limitation in available technology. Until recently, it was virtually impossible to

9create a variable acoustical environment. Doing so required large pieces of moving paneling, padding,

and carpeting, which made the procedure expensive and impractical. Thus, the only possible way of ex-

posing experimental subjects to different environments was to play them "canned" pieces of music,

recorded in different environments. Electronic processing of a live performance in real time was prohib-

itively expensive. Bringing an entire audience and performing group into a dozen different halls is im-

practical. Until recently, money and practicality played a strong role in the stagnation of the field.

Recent advances in Digital Signal Processing technology make it possible to alter the acoustical charac-

teristics of a room at the press of a button. Many companies have made electronic devices specifically

for that purpose. Among them are Lexicon Corporation, SigTech, and Stell Acoustics. Technology has

finally caught up to the needs of acousticians, and experimentation in the field has become possible.

"Possible" does not necessarily translate to "Easy." A single project could never completely characterize

a field which has evaded acousticians for centuries. Therefore, this paper should be viewed as an ex-

ploratory foray--a preliminary piece of work, designed to determine what research needs to be done,

rather than to conclusively prove a hypothesis. Hopefully, this small project will be picked up by the

acoustical community, and will be built upon.

The following section comprises a review of much of the available literature on concert hall acoustics, to

bring the reader up to date on the field. Although every effort was made to be as thorough as possible,

limitations in time and article availability prevented it from being comprehensive.

10

Literature Review-

THE SCIENCE OF ACOUSTICS

Just over 130 years ago, Hermann von Helmholtz wrote a landmark work on the physics of acoustics,

On the Sensations of Tone (Campbell and Greated 2). It was at that point that acoustics graduated from

being a concept to being a science. Helmholtz's book opened up discussion and research on all manner

of acoustical phenomena. Acousticians realized early on that the problem of improving concert hall

acoustics was an important one. Unfortunately, that area was doomed to lag behind the rest of the

acoustical sciences, for several reasons.

Concert hall acoustical analysis differs from the other acoustical sciences in that it can not rely as much

on trial and error. Musical instrument design lends itself to speedy progress because prototypes can be

designed, tested, and rebuilt within a matter of days. Concert halls, on the other hand, take a decidedly

longer time to build, and the only available prototypes for new halls are previously built halls (Campbell

and Greated 525). Twenty or more generations of violin can be constructed in less time than a single

concert hall. It is no great wonder that the field of concert hall acoustics lags behind the other areas of

the discipline.

Not only are concert halls more expensive and difficult to build, they are "exceedingly complex" to ana-

lyze, because of the number of parameters involved: analysis must include the shape of the enclosure,

the properties of the materials used, furniture, characteristics of the sound source, position of the audi-

ence, and a near infinite number of other variables (Olson 266). Until very recently, the resources

needed to analyze this large quantity of data simply did not exist (Olson v).

11Beyond technological shortcomings, another problem existed that slowed the growth of the science of

room acoustics. Acousticians knew that the acoustics of the room in which music was played influenced

a listener's opinion of performance (Campbell and Greated 525). However, early research in acoustics

was carried out "with much simpler sounds and in laboratory conditions far removed from the ambience

of the concert hall (Campbell and Greated 40)." Stereotypically, acousticians worked in their laborato-

ries, and musicians kept away. This dividing line plagued the science of musical acoustics for centuries,

until the twentieth century. It is fortunate that musicians and acousticians have finally managed to come

closer together, and the science of musical acoustics is growing because of it.

HISTORY OF ACOUSTICS

Before describing the technology and cutting edge research in acoustics, it is necessary to explain the

underlying principles and tenets of general concert hall acoustics. Following is a brief, non-technical

discussion of some characteristics of concert halls which have been of particular interest to acousticians

in the past.

Reverberation Time

In conversations among musicians about acoustics, reverberation is almost always the first attribute

mentioned, probably because it is the most familiar (Gade 18). The presence of reverberation "consider-

ably alters the quality of ... music (Backus 168)." Some musicians even maintain that reverberation time

at middle frequencies is the "most important" musical factor to be considered

when designing a performing hall (Geerdes 51). Deciding on a reverberation time, or "T60" when de-

signing a hall is not a simple chore. In the words of John Backus, in The Acoustical Foundations of Mu-

sic, "the optimum reverberation time for an auditorium is . . . a compromise between clarity on one hand

and a satisfactory sound intensity on the other. For a given auditorium the best reverberation time

12will depend on the use for which it is designed . . . (170)." Backus says that a hall with too large of a

T60 is analogous to a piano with a stuck sustain pedal: individual notes become obscured and muddy

(168). A hall with too short of a T60 will sound dry (Gade 15), or "dead (Backus, 170)."

Charts have been published which show ranges of T60 for certain applications, but different charts show

conflicting information. For example, Campbell and Greated list 1.3 to 1.6 seconds as the optimal T60

for Opera (536). Geerdes lists 1.5 to 1.8 seconds (51). Theaters have "optimum T60s" ranging from 1

second to 1.4 seconds (Geerdes 51; Campbell and Greated 536). Despite over one hundred years of

acoustical research, musicians and acousticians still have not unanimously agreed on such a deceptively

simple characteristic.

To add even more complication to the issue of optimum reverberation time, Campbell and Greated point

out that that T60 can be different for different pitches, and that this distribution of T60 over the full audi-

tory frequency range is important. For example, it is generally accepted that 19th-century music should

be performed in a hall in which T60 is smaller at higher frequencies. Baroque music, on the other hand,

sounds better in a hall with a "flat" [constant across all frequencies] T60 (Campbell and Greated 537).

In fact, the "warmth" of a hall is directly related to the ration of T60 at low frequencies and T60 at mid-

dle frequencies (Campbell and Greated 538).

Although the studies on optimum reverberation time do not agree in full, this is not for lack of trying;

RT is merely a matter of personal preference, as are all other hall acoustical parameter preferences. Be-

cause RT has been explored in such depth already, the experimental procedure of this project will not

pay much heed to the effects of RT on performance.

13Frequency Characteristics

The mention of the frequency dependency of RT above raises a larger issue of frequency characteristics

of a hall in general. Some halls are "bright," others are "dull." There is a host of other terms used to de-

scribe the frequency content of the hall's response to a performer's instrument. Not much research was

found regarding the effects of frequency-dependent level of return from an acoustical environment.

Therefore this experiment dives quite deeply into the effects of frequency characteristics of a hall on

performance.

Sound Distribution

One room parameter that is very closely related to reverberation time, about which unanimous agree-

ment has been reached, is sound distribution. Second only to reverberation time, sound distribution is

the most talked about, most widely known characteristic of a hall (Backus 177). Refreshingly, there is

no dissent as to what type of distribution is desirable: it is generally agreed that sound should be evenly

distributed throughout the hall. Unfortunately, that is virtually impossible to achieve (Gade 21). In fact,

there is often a larger difference between different seats in the same hall than between similarly located

seats in different halls (Gade 7). So although there is no disagreement that even distribution is desirable,

so far it seems that this agreement is sadly moot, and acousticians must therefore consider how to com-

promise.

This project pays much attention to sound distribution, in the form of the directionality of the return of

the performer's voice, in the form of reverberation and early reflections, from the concert hall.

Early Reflections

Although reverberation time and even distribution of sound were the first parameters of acoustical spa-

ces to be studied, the development of electronic recording, digital signal processing and directional

14microphone arrays has made it possible to focus less on the very broad, statistical topics of T60 and dis-

tribution, and more on the specific behavior of a hall in the short interval of time after a sound is pro-

duced, in the first tenth of a second or so--that is, to focus on the relationship between the original, "di-

rect" sound, and the first reflections from nearby surfaces (Jordan 114).

When a performer on a stage produces a sound, the sound travels, at the same time, to nearby audience

members and to nearby surfaces. It then rebounds from the surfaces, and continues to rebound until it

reaches a listener, or decays to an inaudible level. Thus, a short time after they experience the "direct"

sound from the performer, audience members experience the "reflected" sound from nearby surfaces.

The time interval between the direct and reflected sounds has a very important effect on how the audi-

ence will feel about the sound--specifically, how "intimate" the space is. Recent research suggests that

this time interval should be less than 20 milliseconds (Backus 179; Campbell and Greated 540). It has

also been known for some time that the direction of arrival of the first reflection also affects an audi-

ence's level of pleasure. It is desirable to have the first reflection arrive from the sides, rather than from

above or behind (Campbell and Greated 540; Backus 181; Jordan 115), or the hall will sound "dry (Jor-

dan, 115)." In this project, some time was devoted to the effects produced by different early reflection

patterns.

Echo

One effect of improperly timed and improperly angled reflections is echo. If one particular reflection is

time-wise and intensity-wise separate from all other reflections, i.e., if it can be singled out by the hu-

man ear, it is called an "echo." Echoes in performance conditions can be disastrous (Backus 179).

Sometimes echoes do not decay after they are heard. Instead, an echo can persist, bouncing back and

forth between two parallel surfaces many times before dying out. Such an echo is called "flutter," and is

even less

15desirable than single echoes (Campbell and Greated 542). Obviously, then, it is important to pay careful

attention to direction, intensity, and timing of all reflections. Again, this task involves a great deal of

variables, and is therefore overwhelmingly complex. Just as with reverberation and distribution, acous-

ticians have been forced to make generalizations and compromises. However, there is no counter to the

fact that echo is bad for a performer, and this survey pays no time studying its effects on performance.

Isolation

Isolation from noise is the one acoustical parameter that is not in debate, and possible to achieve. The

ideal hall would have absolutely no background noise. However, the behavior of the human ear is such

that sufficiently soft sounds absolutely can not be heard (Beranek, 394). Further, it is possible for louder

sounds to completely "mask" softer sounds (Beranek, 404). This masking effect means that there is a

level of background noise that can be considered "low enough" for performance conditions. The only

challenge, then, is to achieve this level: to soften the noise of ventilation systems, to acoustically insulate

walls from outside noise, and so on.

This study does not devote any time to isolation. Although lack of isolation is an irritation to any per-

former, the environment used in this experiment was not flexible enough to provide any degree of accu-

racy as regards background noise.

CURRENT RESEARCH IN ACOUSTICS

Obviously there are still mysteries in the realm of room acoustics. In the words of John Backus, ". . . the

subject of auditorium acoustics is by no means completely understood. Research and argument are still

going on, and will continue to do so (181)." Thankfully, the field if acoustics is no longer the exclusive

16realm of physicists in laboratories: it has become a diverse, interdisciplinary field, comprising not only

physicists but physiologists, psychologists (Campbell and Greated 2), and musicians. Because of this

unification of artists and scientists, some of the most recent advances in the last decade (Jordan 116)

have been in subjective analysis (Olson v)--that is, determination of which measurable attributes of a

concert hall correspond to which subjective impressions. In fact, that research is used as a point of de-

parture for this paper.

In "Acoustical Criteria and Acoustical Qualities of Concert Halls," Vilhelm Lassen Jordan asserts, "the

question of correlation between objective measures and subjective impressions of acoustical quality [has

become] more and more urgent." Up to a little over a decade ago, research in subjective perception of

hall acoustics was limited to a few pioneers. W.C. Sabine conducted experiments in 1923 which tried to

determine optimal reverberation times for concert halls. Leo Beranek is credited with doing the "most

extensive" survey of this kind, in 1962, studying more than 50 concert halls worldwide. Both men used

musicians' subjective impressions of halls, combined with objective measurements of these halls, to de-

termine what, in a hall, was "good," and what was "bad (Gade, 8)."

A "large number of studies" have been done to relate subjective and objective characteristics (Bolzinger,

Warusfel, and Kahle) of halls. Many of these studies, including Sabine's and Beranek's, included musi-

cians as experts. In fact, musicians can be considered experts in hall acoustics, as they relate to perfor-

mance. A recent survey found that musicians quite often communicate with each other about the short-

comings and advantages of different halls (Gade 40). 81% of musicians surveyed agreed that acoustics

were important to the performer (Gade, 36), and 63% of the surveyed musicians were aware of gaining

the ability to be aware of, and adjust to, the acoustics of a hall (Gade 35). However, less than 30% of

the musicians had ever spoken to an acoustician or someone technically familiar with acoustics

17(Gade 41)! Obviously more needs to be done to open the lines of communication between acousticians

and performers. Many recent studies have done just that.

One paper, done by Vilhelm Lassen Jordan in Denmark, established very clearly which numerical mea-

surements corresponded to certain impressions named by musicians. Jordan defined a specific set of

acoustical parameters which can supposedly uniquely characterize a hall. For example, he defines

"Early Decay Time," or "EDT" as the amount of time it takes an initial sound to die out by 10 decibels

(see Appendix 1), and related it to the subjective characteristic of reverberance. Another example was

the idea of "Deutlichkeit," or Clarity, which corresponded to the amount of energy reaching a particular

spot during the interval from 0 to 50 milliseconds, to the amount of energy reaching that spot after 50

milliseconds. Although this paper was very thorough in making measurable parameters of previously

nebulous ideas, it did not specify what values corresponded to "good" acoustics. That job was left for

later study.

One recent survey, done in 1981 by Anders Christian Gade at the Technical University of Denmark, did

just this. Its goal was to determine what objectively-measurable room parameters corresponded to

which subjective impressions. To this end, an interviewer with a list of questions took a group of musi-

cians, one at a time, into a room, and asked a battery of survey questions. The survey was aimed to de-

termine what characteristics musicians found desirable in a hall. In order to analyze the data, the inter-

viewer had to "translate" the words of the musician into a group of standard terms. It was determined

that all musical impressions could be mapped to seven terms: Reverberation, Hearing-each-other, Sup-

port, Timbre, Dynamics, Time-delay, and Change of Pitch. Reams of statistical analysis determined

what values for each of these characteristics musicians found most important--or at least, which of these

characteristics musicians liked to talk about most. The surveys also supposedly hinted at what

18characteristics of playing (tempo, attack, volume, and the like) were affected by which hall characteris-

tics (reverberation, support, etc). This particular survey had the opposite problem as that done by Jor-

dan--it gave no values or ranges of values for the parameters mentioned, because, in the words of the

writer, "at the moment so little is known about this field that an interview survey collecting opinions un-

biased by the presence of technical equipment would be of value (11)." This leaves a perfect niche for

the project described in this paper, which combines the survey technique with technical equipment.

Even research that has been done with musicians, like Gade's, has flaws. Most experiments in this field

deal with musicians as listeners, not as performers, "and may hence fail for the description of the sensa-

tions of the musicians on stage (Bolzinger, Warusfel, Kahle)." Simply put, researchers have not been

using musicians to their full potential: as experts in determining which acoustical characteristics will en-

courage a virtuoso performance. After all, "acoustics may be regarded as one of the main qualities of

the musician's working environment (Gade, 7)." One thrust of modern acoustical research, then, is to

determine how performance hall acoustics affect the performer on stage (Bolzinger, Warusfel, Kahle;

Gade 8; Backus 183, 185; Jordan 121).

One may wonder: if we have already determined what conditions are desirable for a listener, why would

the musician's perspective be any different? There are several reasons. First, acoustic conditions are

seldom the same on stage as in the audience. Second, musicians' needs are very likely not the same as

the needs of an audience (Gade, 7), because a musician's relationship with a hall is active--it involves a

"feedback relationship (Bolzinger, Warusfel, Kahle):" broadcasting, receiving, adjusting, and broadcast-

ing again (Gade, 8). Of all of the studies and research done in the area of musical acoustics, only one

study has focused on this feedback relationship.

19In May of 1994, Bolzinger, Warusfel, and Kahle did an experiment to determine the effects of changing

environmental acoustics on the performance of the concert pianist. Seven professional soloists were

brought into a darkened concert hall with adjustable acoustical properties, and were asked to play a ses-

sion that consisted of a few minutes of practice, some short imposed exercises, and some music of their

choice, which had to be all written--it could not include any improvisation. They were asked to play this

sequence nine times. Each time, certain acoustical parameters of the hall were changed. The hall in

which they played was physically alterable, meaning that in order for changes to occur, barriers had to

be moved, the ceiling was raised or lowered, walls' material was changed, and so on. Only the acousti-

cal properties of the hall were changed. The pianist played on the same piano, in the same hall, on the

same day. The changed parameters were T60, reverberation level, the ratio of direct to reflected sound

at the pianist's ears, and the frequency characteristic of the reverberation. Audio was recorded on a

MacIntosh computer, and the nuances of the pianist's performance was recorded via a MIDI grand pi-

ano. After each of their sessions was recorded, the musicians were asked to answer a brief survey about

their impressions about the hall.

Analysis of the data is still continuing, but preliminary analysis found that the reverberance of a concert

hall definitely affects the intensity with which a pianist plays. However, because the hall had physical

limitations on alteration of parameters, it is not clear whether it was the reverberation time or the rever-

beration intensity which affects that change.

The correlations of the musicians' impressions were higher than the correlations of audience members,

confirming the suspicion that musicians are more 'in tune' with their acoustical environment. This study

effectively contradicted earlier research, and held that reverberation time has little effect on the musi-

cian's choice of tempo. Even more interesting, one setting was almost unanimously preferred by the mu-

sicians

20involved, regardless of what style of music they played! These contradictions emphasize the need for

more investigation into the phenomenon of performer/hall feedback. It is possible that early survey-

based research in this area is flawed, either because musicians have difficulty putting their impressions

into words, or they are not always consciously aware of a hall's effects on their performance (Gade, 11).

THE CUTTING EDGE OF ACOUSTICAL RESEARCH

We have seen that there is no shortage of research dealing with impressions of a listener in a given

acoustical environment. It is also obvious that the research done in this area up to now has flaws, and

would benefit from further exploration. It is already known that room acoustics have a psychological

and physical effect on the performer. Musicians in good environments feel more inspired, can concen-

trate better, and do not have to adjust their playing style to compensate for poor acoustics (Gade, 29).

As we have seen, though, there is a void surrounding the idea of the specific effects of an acoustical en-

vironment on a performer. Of those papers that did delve into this field, only a "small fraction" are

based on empirical data (Gade, 8). Some of the survey-based studies had problematic question formats:

one only encouraged musicians to pick one acoustical effect as "the most important," and did not bother

to rank the rest (Gade, 23). The one study that did base its results on empirical findings had trouble with

its experimental process, and could not completely isolate specific causes (Bolzinger, Warusfel, Kahle).

Therefore, it is logical to conclude that future research should concentrate in two areas: first, it should

concentrate on determining the effects of concert hall acoustics on a musician's performance, and sec-

ond, it should do so empirically. That was the aim of this project.

21

Experimental Procedure-

GOALS

The primary objective of this experiment was to determine how certain acoustical conditions affect a

musician's performance. No judgment was made, before the experiment was complete, which environ-

ments were considered "good" and which were considered "bad." Although some results were expected,

the ultimate results were determined empirically from the performances generated under the given con-

ditions. The project has a dual objective.

The first project objective was to determine what physical and psychological effects an alteration in

acoustical environment can have on a musician's performance. In other words, how the performer ad-

justs and how performance suffers under certain conditions, and excels in others, and how musicians

feel in the environments in which they perform.

The second objective was to determine whether a musician's impressions of his performance are accu-

rate. That is, whether a musician would rate his performance the same as an objective audience mem-

ber, and how performance hall acoustics affect the musician's ability to judge his performance objec-

tively.

METHOD

Subjects

Before proceeding, subjects had to be found for participation in this experiment. Because of budget re-

strictions, it was necessary to solicit volunteers. It was already determined that the experiment would

rely upon putting musicians in different acoustical environments. The challenge was to determine what

instruments should be used in the survey.

22In the words of Murray Campbell and Clive Greated, the human voice is "the most personal and expres-

sive of all instruments (3)." Although this may initially seem a pompous attitude propagated by singers,

there is truth to the statement. The singer is indeed more personally involved with his instrument than

any other musician. If the instrument is hurting, the singer knows it instantly, and suffers with it.

Voices are unique to the individual, and are used (by some better than others) for an entire lifetime.

Also, solo singers are at greater risk than other instrumentalists if they are exposed to a hostile acoustical

environment, because, in Gade's words, "the tendency is to 'force' sound, which deteriorates the timbre

of the sound (32), and can even cause damage to the voice."

Not only are singers more "in tune" with their voices, they are bound to be more personally involved

with the hall in which they are singing because voices, unlike pianos, have no sounding board. The hall

is their sounding board, an extension of their instrument, and therefore affects them more profoundly

than any other instrument (Gade 37). Quoting Carl Shalk, Lovelace writes "the building itself is an in-

strument."

Even beyond these very effective points, practical experimental concerns made vocalists a logical

choice: the human voice is portable. Unlike a piano, it can easily fit through doorways. It does not re-

quire electrical power. Its only disadvantage is that it may tend to wear out more quickly than other in-

struments--a topic which is described in the data analysis, later in this paper.

The combination of these reasons led logically to the conclusion that the participating musicians for this

experiment would all be singers. That is a rather broad description, however. Opera singers certainly do

not fit in the same category as rock singers. Sopranos certainly do not fit into the same category as

bass/baritones. It was decided that variety would be a strength in determining the demographics of the

participants, and thus the singers invited to participate were gleaned from a variety of styles, ranges,

23

Ray Bauwens sings in the chamber

timbres and experience lev-

els. Because previous research has shown that sensitivity to room parameters is a learned trait in musi-

cians (Gade 28, 35), and that solo singers are more aware of what constitutes a good performance, (Gade

2, 29) all of the singers chosen had at least some solo performance experience. The initial contact letter

sent to the performers has been duplicated in Appendix 2.

The participating singers in this experiment are Ray Bauwens (referred to as RB), a part-time profes-

sional tenor from the Worcester area with extensive classical and opera solo experience; Christina Free-

man (now Christina White, but referred to as CF), a soprano from WPI who has had years of experience

24with the choral environment, a bit of musical theater, and a bit of solo work; Rebecca O'Brien (RO), a

part-time professional soprano hailing from the Boston area with many years of classical and operatic

solo experience; Jean-Pierre Trevisani (JP), a professional tenor from WPI who has participated in the

Metropolitan Opera's Young Artists program; and Wendy Manas, a soprano from WPI who has years of

choral experience, some musical theater, and some popular/patriotic solo experience.

Music

One challenge in designing the experimental procedure was the decision of what type of music would be

sung. The songs had to be familiar, so that memorization of the pieces would be unnecessary, since

sheet music in the chamber would have provided extra acoustical reflections to the singers and skewed

the data. The music obviously had to be vocal, have some sort of artistic merit (i.e., Happy Birthday To

You wasn't a viable choice), be singable by all vocal parts, and with the exception of the a cappella

piece, had to have a simple piano accompaniment. Although it would have been desirable to have music

which was

25phonetically balanced--that is, music that has a statistically even distribution of English phonemes--no

phonetically balanced songs could be found.

Gade chose classical pieces for his work, because of the number of performers involved, and because of

the dependence of classical music on room involvement (11). Rock music, for example, would not be

appropriate, because rock bands often make use of electronic equipment, and therefore are not as sensi-

tive to room acoustics. This study thrust more toward patriotic music: America the Beautiful was sung

with accompaniment, and The Star Spangled Banner was sung a cappella. Each singer also performed a

piece of his or her choice.

Ray Bauwens's chosen piece, as well as Jean-Pierre Trevisani's, was Giordano's Amor Ti Vieta.

Christina Freeman/White sang Rutter's Pie Jesu. Rebecca O'Brien performed Barber's Sure On This

Shining Night, and Wendy Manas used Rock-A-Bye Your Baby, arranged as part of a medley of twenti-

eth-century American songs. All of the soloists provided their own piano accompaniment on cassette

tape.

Equipment

Unfortunately, it was not possible to transport the musicians between real performance halls. The next best option, then, was to design an artificial acoustical environment which could be changed with the touch of a button. Ideally, this room would have been alterable by addressing the parameters discussed in the Literature Review section of this paper: reverberation time at different frequencies; reverberation intensity at different frequencies; distribution; early decay time; early reflection directionality, concen-tration, and intensity; isolation, and so on. Unfortunately, limitations in budget prevented the creation of a very high-tech environment in which to work. An in-depth description of the chamber that was used, which evolved from the equipment which was available, follows.

26

The Anechoic Chamber atBose Corporation

The first requirement in designing

an artificial environment is to have a place in which to build it. Obviously, the room in which it is im-

plemented must have as little "acoustical personality" as possible: otherwise, the room's natural acous-

tics would interfere with the artificial ones. Fortunately, there is a room with near zero response to all

sound within fifty miles of the WPI campus: the anechoic [meaning "no echo"] chamber at Bose Insti-

tute in Framingham, MA. Bose Corporation was kind enough to allow the use of the facility at no

charge, whenever it was not being used for research by Bose engineers, in exchange for a copy of this

document.

With a place to build the environment, the next step was to put together the electronics for acquisition,

processing, and rebroadcast of the singer's voice in the chamber. Several Digital Processing (DSP) sys-

tems were considered, among them the Lares system from Lexicon, the CP1 from Lexicon, the Ensoniq

DP4, and the Yamaha DSP1. Because Bose Corporation already had a Lexicon CP1 effects processor

on site, the CP1 became the basis for the artificial environment.

27

To acquire the singer's voice, the system used two Shure SM57 microphones (practically the industry

standard in live vocal performance), feeding a Mackie eight-channel mixer as a microphone preampli-

fier, all borrowed from the WPI Instructional Media Center. The stereo mixer output fed the CP1 inputs

directly. The singers were also fitted with a pair of glasses with binaural microphones mounted over the

ears, borrowed from Professor Richard Campbell of Bang Campbell Associates. It was originally in-

tended that the signal from these microphones would be used as an accurate measure of the singers' vol-

ume in different environments, because, unlike the volume of the signal reaching the SM57s, the signal

28

Wires, Wires, Wires--the rear of the amplifier rack

151 151

151

151 151

151

(Main)

(Left) (Right)

(Rear)

SM57s

Fig. 1 -- Room Configuration

29reaching the binaural mi-

30crophones was independent on a singer's head position. Unfortunately, the microphones were powered with a n

ine-volt battery, and their output was heavily dependent on the

All microphone signals, comprising the two Shure SM57s and the two channels of the binaural glasses,

were recorded on a Tascam DA88 digital audio recording system, also provided by Bose corporation.

The six CP1 outputs drove three stereo power amplifiers, a Crown D-75 for the CP1 "Main" outputs, a

Crown MT2400 for the CP1 "Rear" channels, and a Crown MT600 for the CP1 "Side" channels, all bor-

rowed from Bose Corporation. All of the amplifiers fed Bose 151 loudspeakers, comprising a matrix of

six speakers: two directly in front of the singer, two to the sides, an two at the rear (see Fig. 1).

31The singer's accompaniment was provided by a Bose Roommate speaker, placed on a crate in front of,

and to the left, of the singer. The Roommate was fed by a Califone tape deck, which was operated out-

side of the chamber by the person conducting the experiment. Exact adjustment of the volume of the ac-

companiment was impossible, because of the variations between tapes. Every effort was made to keep

the accompaniment volume as constant as possible. If accompaniment volume was a factor in a change

of performance style, that fact will show up in the analysis of the a cappella segments.

A comprehensive list of all of the equipment used in this project, including cables and tape, can be found

in Appendix 3.

Environments

With an adjustable environment set up, the next step was to determine the specific settings in which the

singers would perform. A great deal of thought was spent on deciding how many environments were

necessary to gather a reasonable amount of data, without tiring the singers. It was finally decided that

ten environments provided enough variation in environmental parameters to make a good "first cut" at

this sort of research. A singer's session would consist of all ten environments, plus three repetitions

which would be chosen at random from the ten.

Ideally, the parameters to be varied would have been expressed in terms of standard acoustical measure-

ments--i.e., "-3dB in the 1kHz octave band, -10dB in the 2kHz octave band, etc.," or "RT of 3.2 seconds

at 500Hz, 2.5 seconds at 1kHz," and so on. However, equipment limitations made it necessary to ex-

press room parameter changes in terms of equipment settings, such as volume levels, power amplifier

on/off, LIVENESS, etc. A full list of the characteristics of each setting, and a list of the order in which

the settings were presented to each performer, can be found in Appendix 4. Setting 1 was the

32"Standard" setting, from which all of the other settings were derived by making one or two modifica-

tions to the equipment setup. Setting 2, the "High Enhanced" setting, was created by turning the Mackie

High EQ to maximum, and adjusting the CP1's ROLLOFF parameter to 14.9kHz, to create a large high

frequency response. Setting 3, "Most Live," was derived by changing the CP1's LIVENESS setting to 6,

the highest setting. Setting 4, "High Inhibited," was produced by turning the Mackie Mixer's High EQ

to its lowest point, and changing the CP1's ROLLOFF parameter to 329Hz, resulting in a muted high

frequency response. Setting 5, "Less Presence," was set up by turning the EFF LEVEL on the CP1 to -

20dB from the standard -14dB, effectively reducing the level of the room's return by half. Setting 6,

"Anechoic," was the dead anechoic chamber, with all equipment turned off. Setting 7, "Fan Room" was

created by changing the ROOM SHAPE parameter on the CP1 to "FAN," which created a different early

reflection pattern. Rooms 8 through 10, "No Sides," "Reversed," and "Sides Only," were created by

turning the power amplifiers on in different configurations, simulating different directional patterns.

It should be noted that none of the room settings sounded perfectly natural. Due to equipment and time

limitations, it was necessary to settle for approximations of real environments. The differences between

the artificial environment settings was an exaggeration of the differences which exist between real con-

cert halls. The results of this study should be read with this in mind. Even if the results are not predic-

tive of exactly what occurs in natural environments, they at least add to the body of knowledge available

about the interaction between musicians and their environment.

Procedure

With singers gathered, an environment constructed, and a plan of attack laid out, the next task was to

gather data. For all singers, an introductory script (which can be found in Appendix 5) was read by the

author, the singer was sealed into the chamber, and the first performance began. The singer was pro-

vided

33

RB Fills out his survey sheet

with a summary of the script's in-

structions to follow once in the chamber (Appendix 6). At the end of the performance set the chamber

was opened up, the singer exited, drank the amount of water allotted them, filled out the three survey

sheets (Appendix 7), and repeated the process. When the singer became tired or claustrophobic, a fif-

teen minute break was taken.

Ray Bauwens was the original test subject for the procedure, and because of limitations in the number of

singers available, he was called back to do a "real" experimental run, complete with recording. In the

initial testing of the procedure, he did not encounter any discomfort with performing three songs thirteen

times. However, without exception, the five singers all described fatigue setting in after six or seven tri-

als. In fact, Jean-Pierre Trevisani refused to continue to sing after trial number six, so the data from his

trial is incomplete, and has skewed the overall data in favor of some of the environments in which he did

not sing. Regrettably, this kind of experience can be expected when dealing exclusively with volunteers.

34Once all of the data had been gathered, a panel of three musicians was assembled to analyze the record-

ings of the singers' performances, to determine if their impressions of their performances were valid.

The forms used in the evaluation of the performances can be found in Appendix 8.

The following two sections describe the analysis of the data gathered in this experiment. The first half,

Environment by Environment, is a compilation of the five singers' impressions of each environment, and

contains some interesting reactions on the part of the singers. The second half, Performance by Perfor-

mance, is a summary of the judgments of the musician panel on each singer's performance.

35

Analysis of Data-

METHOD OF ANALYSIS

Part One is an environment-by-environment analysis of how the performers felt in the different acousti-

cal environments. Because there were not enough performers to achieve statistical significance, a meta-

statistical approach was used. In the case of open-ended questions, such as "Acoustically, what would

you say this setting lacked," two types of answers made it into the final report: those that were agreed

upon by two or more performers, and those that were contradicted. In the former case, the agreeing per-

formers are quoted together (two trials of the same singer in the environment are counted as agreements)

under a "+" followed by a summary of the singers' point of agreement. In the latter case, the disagreeing

performers are listed separately from the agreeing ones, under a "-" followed by a summary of the

singers' point of contradiction. Answers which did not fit into one of these two categories were dis-

carded, except in rare cases. The answers and summaries are followed by an author's analysis of the

phenomenon being encountered. The letter/number codes of the form XX# denote the singer's initials

and the trial number for that particular singer.

All judgments as to what performers were describing, and whether their statements agreed or disagreed

with each other, had to be judged as objectively as possible by the author; however, because musical ter-

minology is sometimes holistic, creative judgment was sometimes necessary to interpret what the musi-

cians were in fact saying.

Answers to numerical questions ("Rate this environment," and the like) were statistically analyzed in

terms of arithmetic mean, median, and high and low extrema. Further analysis is unnecessary, because

of the statistical insignificance resulting from the limited number of data points.

36Part One of the analysis aims to get a sense of the singers' impressions of the environments in which

they performed. This can be used as a point of departure for a second pass over the data to determine

how well they performed in the environments. Part Two does just that, using the impressions of out-

siders listening to recordings of the musicians' performances.

Because the questions asked of the listeners were different from the questions asked of the singers, the

data could not be judged like the data of Part One. Instead, the focus is on general trends in correlations

between comfortability level and certain types of performance problems, such as glottal stops, pitch, and

vocal timbre. Because of the large number of questions involved, trends are extraordinarily difficult to

find in the data. However, the graphical method used to present the data in Section Two makes it possi-

ble to find trends visually, rather than relying on on-paper numerical analysis. Further, the author offers

to search his data for further trends, if the reader is curious about other types of analysis.

37ANALYSIS, PART ONE: ENVIRONMENT BY ENVIRONMENT

All environments were produced using the Lexicon CP1 effects processor. Because the only room mea-

surement technique available was MLSSA, and because MLSSA failed to return valid data about the

characteristics of the environment (possibly because of time variant algorithms used inside the CP1 pro-

cessor), the environments are subjectively labeled ("High Enhanced," "Most Live," and so on), and tech-

nically designated by the settings of the equipment used to produce the artificial environment. Using

these descriptions, a full reconstruction of the performance conditions of each environment is possible.

Environment 1: "Standard"

EFF LEVEL -13dB Crown D-75 on fronts, vol 100%

ROOM 4 Crown MT2400 on rears, vol 15

BAL Equal Crown MT600 on sides, vol 12

VOL -8dB All CP1 gains at max

AMBIENCE 60 degree panorama

SHAPE Rectangle Input level horizontal

LIVENESS 4 Mackie mixer mic pre-amp gain vertical

ROLLOFF 2.9KHz

PAN 28

POSITION 127

ANGLE 57

This setting was chosen as a midway point between extremely live environments and extremely dead en-

vironments. The other nine environments are exactly the same as this one, with a single parameter

change either in frequency, directionality, or volume level of the environment's acoustical return.

38Acoustically, what would you say this setting lacked? How did you notice it?

+ Not enough response at higher frequencies

RB1: "I would lose the sense of sound returning to me in passages in the upper part of my range"

RB5: "It lacked the brilliance of the previous setting -- I didn't sense a brightness of sound"

RO1: "Room for the upper notes."

- Too much response at higher frequencies

RO6: "Too live."

WM4: "The ability to absorb 's' sounds"

There seems to have been too much high frequency content in the room's return. Throughout all of the

trials, many of the singers' comments indicated that the artificial acoustic environment tended to sound

unnatural. It is also likely that at times the equipment was "saturating." That is, it reached a point where

it was trying to produce more high-frequency signal than it could. This phenomenon could be the result

of using the CP1 effects processor, which was originally designed for use in home theater systems. The

result is similar to the high frequency feedback found in poorly designed Public Address systems. This

observation has no relevance to real concert halls that do not use amplification.

Acoustically, what would you say this setting did not lack? How did you notice it?

+ Resonance

RB1: "It did not lack a sense of brilliance or resonance."

RB5: "Didn't lack resonance -- it was focused and well balanced."

RO1: "The middle range felt very good."

RO6: "It had a lot of acoustical space. I sounded very loud."

WM4: "Reverb and resonance. I could hear my voice resonate."

39All of the singers agree on a single term to describe the setting: it was resonant. RO1 probably hit on

the reason, with her comment, "the middle range felt very good." The singers were probably noticing

that, although the high frequency component of their voices was saturating the equipment, the "power"

part of their voices--the fundamental frequency of their voices' harmonic series--was returning to them,

even in the loudest portions of their performance.

How do you think you adjusted, in order to sound your best in this environment?

+ Held back

RB1: "When I noticed a decrease of reverb or resonance in the upper range, I tried to back off

the sound"

RO1: "I held back a little"

WM4: "Control my 's' sounds - I held back."

- Did not hold back

RO6: "I brightened the sound -- I felt that improved the pitch."

CF6: "I just cut loose."

In all cases under "+," the singers are describing holding back on the high frequency content of their

voices. RO mentions in another question that that she "darkened" the sound. It would seem that some

of the singers tried to correct for the environment's shortcomings by changing their vocal timbre or vol-

ume at high frequencies.

The contradictions seem to indicate despair; that is, the singers have realized that the environment is not

an ideal one, so they have decided to "cut loose" and roll with whatever the environment can provide for

40feedback. The singers seemingly realized the environment was not high-frequency friendly, and tried to

"outsmart" it by intentionally not adjusting.

If you could change one specific acoustical property of this environment to make it better, what would it

be? Why did you choose that particular property?

+ Less Reverb

RO6: "I would take away some of the resonance -- it makes me use too much voice -- I would

also take some of the reverb -- if you hear lower pitches sometimes you can get into a

snowball effect."

CF6: "Less REVERB. Gad. I don't want to know every time I messed up."

- More Reverb

RB5: "I would give it a bit more reverb - I would like the feeling of the sound lingering a bit

longer."

+ Fix the high-frequency saturation

RB1: "...sustain the more brilliant sounds in a better fashion."

RO1: "More room for the upper notes."

WM4: "Take away whatever controls 's' sounds, it is annoying."

Interestingly, the only singer who wanted more reverberation was RB, the only male who sang in this

environment. I strongly believe this is due to the frequency envelope of the reverberation; that is, there

was quite a bit of reverberation at higher frequencies [hence the saturation], and not enough at lower fre-

quencies. This reinforces the statement which was made in the introduction about ideal RT being a mat-

ter of personal preference.

41Does this setting remind you of any halls you have sung in, or listened to music in, before?

+ Stone rooms, hallways, stairwells

The room was very bright, like a rooms with smooth stone walls tend to be.

How do you think a member of the audience would rate your performance in this setting?

+ Full, balanced

RB5: "Pleasing--well balanced"

- Not balanced

RB1: "Sound was not balanced--top notes were thin."

CF6: "Sounds that shouldn't be there seem more pronounced."

This is a terrific case study in the ability of singers to adjust to performing in almost any environment.

RB had sung in four different artificial settings before he made the contradictory comment that Setting 1

was well balanced. Most likely, compared to the setting he had just come out of (the High Enhanced

setting), the high end saturation was much less offensive to his ears than it was upon first entering the

chamber. Thus his opinion was very much dependent on the context in which he heard the setting.

How would you critique your performance in this setting? What mistakes did you catch yourself mak-

ing? + Problems relaxing

RO1: "Mediocre. I didn't really think about breath support."

RB5: "The top notes are getting tight."

RB1: "Breathing was inconsistent."

WM4: "I became self conscious of 's' sounds"

42In general (even in the comments not included), the singers seemed stressed and uncomfortable singing

in this environment. In no cases did they hint that they were very pleased with their performance in

these conditions, possibly because, as CF continues to point out, they heard too much: too much of their

own mistakes, too much of their 's' sounds, and possibly even too much of their own breathing. This

brings up a point: perhaps being in circumstances where one hears too much of certain things (i.e.,

which has 'spikes' in certain frequency ranges) can be extremely dangerous to a performance.

How friendly would you rate this environment?

Mean: 68.3% Median: 75% High: 90% Low: 15%

How responsive would you rate this environment?


How reverberant would you rate this environment?

Mean: 85% Median: 85% High: 100% Low: 80%

How supportive would you rate this environment?


How resonant would you rate this environment?


How powerful do you feel in this environment?

Mean: 78% Median: 76.5% High: 95% Low: 55%

How would you rate this setting, overall?

Mean: 71% Median: 76.5% High: 95% Low: 30%

The large range of opinions expressed in the numerical data lead me to wonder whether numerical sur-

vey techniques for situations like these is possible, valid, and consistent. It seems as though the reason

this

43field has been so elusive in the past is that numerical techniques are so difficult to tie into subjective im-

pressions.

However, for the sake of getting an overall view of all of the environments, all straight numerical data

will be included in the survey process. Perhaps by the end of the analysis, a trend will emerge that will

shed some light on the seemingly erratic data.

Environment 2: "High Enhanced"

Standard settings, plus Mackie mixer High EQ all the way up, CP1 ROLLOFF 14.9KHz.

This environment was designed to be very responsive at high frequencies, while keeping the same

amount of responsiveness at middle and low frequencies. The result is a very sibilant environment.

Acoustically, what would you say this setting lacked? How did you notice it?

+ Reverberation

CF7: "The sound went away from you."

WM7: "Reverb (just a little bit)"

+ Too much high, not enough low

RB4: "Lacked fullness in the lower range - it felt top-heavy."

RO9: "Some resonance at the upper notes. They felt tight."

- Did not lack reverb

B4: "Did not lack resonance, reverb, or brightness."

Generally, the artists were very conscious of any imbalance over the full frequency range. Evenness

seemed to be something that they wanted, more than any other characteristic. This is a recurrent theme.

44Regarding RB's comment that it did not lack reverberation or resonance--he may be referring to the large

amount of high frequency feedback in the room, whereas the may be commenting on the lack of low fre-

quencies. In all cases, the artists are commenting upon the same phenomenon, in different terms.


+ Sounded more artificial than the other environments

B4: "I noticed the consonants being reflected back (extremely rare)"

O9: "like singing into a microphone at a stadium."

+ Vocal feedback

F7: "Resonance."

M7: "I could hear every part of my diction very precisely."

All of the singers, off the record, commented on the artificiality of this environment. The author agrees

wholeheartedly that this was the least natural of all of the settings, and is probably not a good example

from which to judge of the effects of concert hall acoustics on a singer. It did evoke some interesting

opinions from the singers, and its results are included in this paper for that reason.

First, it should be noted that feeding singers "technical" terms like resonance in the survey was a mis-

take, because they applied the terms to unrelated effects. In this case, CF and WM are commenting that

they are receiving a lot of their voice in a non-delayed reflection from directly in front of them, rather

like they are singing in front of a marble wall, and they mistake this for resonance, which is altogether

different.

This confusion of technical terms can be accounted for in two different ways: future surveys should ei-

ther

45provide definitions of technical terms in the introduction so that the singer is not tempted to provide

their

own definition of the term if it is not familiar or should forego the use of technical terms altogether.


+ Adjust vocal timbre and technique

O9: "Darkened the quality - i.e., more room further back in my throat"

M7: "couldn't be as free with my singing - had to concentrate on how it sounded in the room."

+ Belt

B4: "I opened the voice up - full throttle"

F7: "I also let it loose again to fill the space."

There are several different phenomena at work here. RO has paid attention to the frequency imbalance

of the setting, and has adjusted her voice to fill out the muted lower frequency range. WM has become

preoccupied with the sound of her voice being reflected directly back at her. RB and CF have opted to

"cut loose" in the environment.

It is possible, at high volumes, to get an adrenaline rush from the sheer intensity of the room's return on

a vocal investment. This "fight or flight" response is similar to the familiar adrenaline reaction to a fire-

works display, loud rock concert, or roller coaster. It is possible that RB and CF have tapped into this

response, and are reacting with a vocal "fight" response.

Although this sounds like a rather bizarre way of explaining their survey answers, the author has experi-

enced this phenomenon, and is convinced that it would be a particularly interesting focal point for fur-

ther psychological study.

46



+ Lower the high frequency reverb, give some lower frequency support

RO9: "I would add some resonance and tone down the reverb."

WM7: "Put in more reverb - I like the way my voice sounds with reverb."

- Don't change

CF7: "I don't think I'd change anything."

Again, the singers are stressing the importance of evenness across the frequency spectrum. CF seemed

to enjoy the "rush."

How do you think a member of an audience would rate your performance in this setting?

+ Good

WM7: "Pretty good"

CF7: "On a good day, probably good"

RO9: "For patriotic stuff, very good"

RB4: "Very exciting (powerful) clear diction."

RB has used a buzzword, "exciting," that furthers the idea presented earlier -- that of getting "driven" by

the environment to a vocal frenzy. Again, this is worth further study.


Mean: 84.5 Median: 89 High: 90 Low: 70

47


Mean: 75 Median: 60 High: 90 Low: 50




Mean: 76.25 Median: 62.5 High: 90 Low: 50







Interestingly, the one question that seemed to have the most unanimous agreement was "How powerful

do you feel in this environment." This can be viewed as further support for the 'fight or flight' theory.

Again, the wide range of results lead me to question the validity of numerical surveys for this type of

study. The open form questions seem to be providing a lot more insight into the effects of the acoustics

on the singers than the numerical data. Fortunately, this is to be expected in a first-time experiment in a

field that has not yet developed.

48Environment 3: "Most Live"

Standard settings, plus CP1 LIVENESS 6. The specific effects of the LIVENESS parameter are un-

known. However, the net result was an emphasis of high frequencies in the return signal from the CP1.

Acoustically, what would you say this setting lacked?

+ Middle and low support

RB2: "This setting lacked a full sound - it was somewhat empty [although with some feeling of

resonance]. I noticed high notes did not elicit a full response."

RB8: "Lacked fullness in the bottom range - low notes didn't blossom"

RO12: "Middle register got stuck."

WM2: "The ability to hear my words clearly. Couldn't hear the dynamic style change in my

voice."

WM8: "A tiny bit of reverb."

- Did not lack

CF11: "I liked this."

This environment, like several of the others, lacked consistency across the full frequency spectrum. This

was partly because of the setting, which was by definition live, and partly because of the setup of the

room, which was prone to a bit of high frequency feedback. CF seemed to enjoy everything that was

thrown her way.


+ Middle and low support

RB2: "The setting didn't lack fullness in the lower range - speaking voice and low notes elicited a

49fuller response."

RB8: "Setting didn't lack resonance or brilliance in the top range."

CF11: "I felt at ease singing in this room."

WM8: "Resonance"

Oddly, in some of their trials the singers felt that the environment lacked lower support, and in other tri-

als they felt that the environment was amply supportive. RB comments that the environment lacked

high support, but had plenty of low support. He later states that it did not lack resonance or brilliance in

the top range. Once again, the singers' impressions are time-variant. Context seems to be having a pro-

found effect on impressions. When faced with environments that at first seemed unfriendly, they per-

formed with comfort, confidence, and ease. This suggests a very interesting starting point for further re-

search: namely, context effects. That is, a study on the effect that a previous acoustical environment has

on the perception of one's current environment.

Not only do these results suggest the existence of context effects, it could be inferred that practicing in

an adjustable environment could be considered part of a training regimen for touring singers. RO com-

mented several times that she would be much more comfortable singing in foreign environments after

participating in this experiment, because she had practiced adjusting (or not adjusting) to what she was

hearing. She further commented that she often felt, while singing in acoustically poor rehearsal spaces,

that her voice was at fault. In the course of this experiment, by singing in ten distinct environments over

the course of three hours, she learned that her voice was in fact consistent, and that the environments

could have a definitive effect on her perceptions of her performance. Perhaps every singer should have

an adjustable environment in which to rehearse, for the purpose of getting used to singing in foreign spa-

ces.

50How do you think you adjusted, in order to sound your best in this environment?

+ Possible saturation of middle upper tenor/middle soprano range?

RB2: "I tried not to oversing the top."

RB8: " I tried to fill out the bottom a bit more to compensate for the brightness at the top"

RO12: "I had to back off my middle register."

Again, the responses to the questions in this setting seem contradictory, even on the same survey sheets.

It is difficult to interpret what the singers are trying to verbalize. It is possible that at low volumes (i.e.,

speaking), the room's response in the lower range was acceptable, but at higher volumes the environ-

ment saturated and was less supportive.



Although the comments varied, the general feeling was that the setting was not balanced. One explana-

tion could be that the Reverberation Times at different frequencies was wildly different. Without know-

ing the internal workings of the CP1 effects processor, and without having full measurements of the set-

tings' impulse responses, it is impossible to tell if this is the case.


ing [including momentary vocal glitches]?

+ Tight

RB2: "Tight - lack of freedom in the top."

RB8: "Tired and tight in the top."

51Suddenly, one can believe that RB was in the same environment for trials 2 and 8, because his vocal re-

sponse was the same. That may be an important point: that whether or not a performer perceives an en-

vironment as different, the vocal response may remain the same, if the environment is the same.

This gives credence to the theory that a singer is not necessarily always aware of the changes that an en-

vironment is having on his or her voice. Later, this study presents the opportunity for outsiders to judge

a singer's performance, very much because of the trap of problems with self-judgment.




Mean: 84 Median: 82.5 High: 95 Low: 74









How would you rate this setting overall?


52Environment 4: "High Inhibited"

Standard settings, plus Mackie mixer High EQ all the way down, CP1 ROLLOFF 329Hz. This setting

was designed to contrast with the "High Enhanced" setting, with an attenuated high frequency response.


+ Not enough return from room

RB11: "Consistency in resonance and reverb - sometimes I noticed a good return, sometimes

no return"

RB3: "Lack any sort of resonance or reverb - sound was gone after I sang"

RO4: "I just felt tired and my head hurt -- it was the first time I was aware that I was in a small

room"

JP4: "'Dry' and 'narrow'"

CF4: "Reverb and liveliness. It was ... near dead."

- Nothing missing

WM11: "Nothing"

Despite that there was sound coming back to them, the singers did not perceive it, because they were

used to receiving a lot of return at high frequencies. This setting provided feedback only at lower fre-

quencies. Because of equipment limitations, it was impossible to determine the exact RT frequency dis-

tribution in this setting. The exact line where reverberation becomes "lost" to the performer's ears would

be a good subject for further study.

RO's comment that her "head hurt" is very interesting. People often have a sensation of cotton-headed-

ness when they first step into anechoic environments, and this setting was the closest that

53RO had come to a completely anechoic setting. Although she was getting some feedback from the

room, she was getting a small enough amount that she was starting to feel the effects of being in the ane-

choic chamber.


+ Some vocal return, but not enough

RB11: "It didn't lack any sense of resonance -- there was something there."

RB3: "It didn't lack a feeling of space -- I could tell sound was in the room -- it just got soaked

up."

RO4: "It was fairly even top to bottom."

CF4: "It had just enough liveliness to make you hopeful but not enough for you to play with"

- Nothing wrong

JP4: "Highs were ok."

WM11: "Nothing"

Apparently this room was a tease, in that it provided some vocal reinforcement, but not enough. RO

commented that it was "even top to bottom," which has been already labeled as desirable in an environ-

ment. All of the above comments seem to indicate that singers would prefer to have a small amount of

even reverberation than a large amount of uneven reverberation.

It should also be noted at this point that after trial WM10, WM's surveys became less and less respon-

sive. Further research should include a larger pool of participants and fewer room settings to cut down

on the

fatigue factor. This is commented on in the conclusions section of this report.


+ Hold back

RB11: "I tried to hold back and not overpower the space (not too effectively)"

RB3: "I pulled the sound back -- reduced volume and intensity"

+ Sustain notes to fill the space with voice, rather than relying on reverb to fill it

JP4: "Sustained sound longer"

CF4: "I tried to fill the dead space more and drove myself flat in the process"

+ Pay more attention to technique

RO4: "I had to think of my technique more"

WM11: "Listen to my voice reflect off the walls"

This is an interesting case study in musicians' adjustment to an environment that is not very kind to mis-

takes. Because there was very little reverberation in the higher ranges, very often the only sound that the

performers were hearing was the sound of their voice as it emanated from their mouths. RB adjusted by

pulling back and cruising through the session. JP and CF held their sound out, trying to simulate the

length of the reverberation that they wanted to hear. RO and WM became preoccupied with the sound

of their voices, and concentrated on improving what they heard.

It may be interesting to follow this route a bit further, and see how singers would react to not hearing

their voices at all while they sing.

55If you could change one specific acoustical property of this environment to make it better, what would it


+ More of a lot of things

RB11: "More consistency in resonance"

RB3: "Liven it up -- make it more responsive in order to give a better sense of sound in the

room"

RO4: "Make the room feel bigger and more alive"

JP4: "More warmth"

CF4: "Liveliness"

This set of data points out that singers do need some feedback from their environment in order to feel

satisfied while performing. Although their terminology differs, all of the singers are essentially asking

for more reverberation across the full frequency range.

Does this setting remind you of any halls you have sung in, or listened to music in, before?

+ Practice/audition rooms

RO4: "Auditions - Auditions!! Which are usually held in tiny dead rooms"

RB3: "Practice room"

The artists are again commenting that the room seems dead, at least at higher frequencies.


General impressions were negative, i.e., "dry," "not particularly memorable," etc.

56How would you critique your performance in this setting? What mistakes did you catch yourself mak-

ing? + Tired

WM11: "Few glitches in my voice, just from being tired"

CF4: "I was flat; I cracked; I messed up words. You name it, it happened. It was sad."

JP4: "A bit off the voice"

RB3: "Slight cracks from time to time"

RB11: "Uneven in places. Different vowel placements and breathing were used to offset

tiredness in the voice"

This set of data illustrates a very important point: under some circumstances, despite efforts by singers

to ignore the poor conditions in which they are performing, their voices can be affected in ways of

which they are not even aware. Not a single one of the performers commented on having changed their

technique to a technique that would be tiring, and yet their resulting performances were "tired," or "off

the voice," as they unconsciously tried to adjust to the environment.









57How resonant would you rate this environment?






Generally, this setting was not very well liked by the singers. WM was apparently either very happy

with a setting that none of the musicians were happy with (all of the Maxima are hers), or she was not

putting her true feelings on the survey paper. There is also the possibility that the equipment was mis-

set for this particular environment, and the author was not aware of the problem. Regardless, her results

can be taken with a grain of salt for this particular setting.

Environment 5: "Less Presence"

Standard settings, plus CP1 EFF LEVEL -20dB. This setting was designed to give the singers a feeling

of being in a less responsive hall. That is, although the amount of acoustical feedback was unchanged,

the quantity was severely decreased.


+ Sound did not envelop the singer

RB12: "It lacked openness -- the sound never 'filled' the room"

CF12: "It was good in the front -- but not high enough"

WM13: "Some reverb from behind, I turned my head slightly"

58+ Not enough resonance

RB12: "...although there was some resonance"

RO3: "Not enough resonance. I felt myself pushing and I just couldn't hear much sound"

RO13: "A little resonance. I felt like I was pushing a bit."

These results suggest a new hypothesis: singers are very much in tune with the direction from which

their aural support is coming. Three of the singers specifically pointed out that there seemed to be a dis-

parity between the amount of reinforcement coming from the front versus the back. Independently, it

was mentioned that there was not enough resonance. It is possible that these two phenomena are related.

As soon as they lost support from behind, they lost the sense of "filling" or "resonating" with the room.

Apparently, singers need evenness not only in terms of frequency, but in terms of directionality. At high

volumes, they did not notice as much, but at lower volumes, when the rear speakers may have been in-

audible, they noticed a lack of envelopment.


+ Consistency across frequency range

RO3: "It was real even top to bottom of range"

RO13: "I'm not sure - it had an evenness of acoustics from top to bottom"

+ Some presence

CF12: "It had some sound -- just not enough"

RB12: "It didn't lack resonance -- the sound was present in the room -- it just didn't move"

Again, it is shown that singers prefer evenness across frequency range to just about any other feature.

CF and RB acknowledged that there was some support, but there was not enough, suggesting that al-

though

59room acoustics should be subtle, they must be loud enough to be clearly audible.


+ Conscious effort not to oversing

RO3: "I tended to push some -- I tried not to after a while"

RO13: "I had to ... lower the breath. I also probably pulled back a bit"

+ Singing toward the source of most support

RB12: "I tried not to let the sound spread -- I tried to keep it focused"

WM13: "I just sang forward and didn't turn my head"

Interestingly, the singers felt constrained by the environment. Even though it was exactly the same as

the first environment, at a lower volume level, they were more consciously aware of the environment's

limitations. It is worth pointing out that the singers seemed to seek out the source of their most support,

and homed in on it: RB and WM both speak of "focusing" and "singing forward," where they perceived

the most return for their vocal investment.

RB's comment could also be considered supportive of RO's comments, in that "focusing" could also

mean pulling the sound back and concentrating on filling a smaller space. In performance conditions,

this could be detrimental.



+ More support

RB12: "I would give it more space. It is important for a singer to have the feeling of sound

60filling a space"

RO3: "It needs more resonance -- so I would push (and eventually trash my voice)"

RO13: "Add a little resonance -- hoping that I would push less"

Singers apparently need to be fully enveloped, acoustically, in order to get a sense of an environment

supporting them. Otherwise, the result can be, as RO says, "trashing" of the voice.


+ Pretty good (RO3, RO13, WM3)













How would you rate this environment overall?


61Environment 6: "Anechoic"

Standard settings, plus CP1 SYSTEM/EFFECT MUTE. This setting was simply the "bare" sound of the

anechoic chamber, with no electronic enhancement.


+ All manner of feedback

RB6: "Lacked a sense of space"

RO11: "It lacked resonance"

JP5: "Everything"

CF1: "It was DEAD"

CF8: "It lacked everything"

WM1: "Reverb off the walls"

WM10: "Reverb, resonance, some kind of feedback"

Several of the singers described the sensation of singing in an anechoic environment as having their per-

formance "swallowed" by the room. This is the only room in which the singers were unanimously

aware of the fact that the environment was a performer-hostile one.


The singers were again unanimous, in observing that the setting lacked everything. WM phrased it in-

terestingly: "when I stopped singing no sound continued in the air." This hints at the idea that singers

may not ever be aware of the individual wall reflections that affect them; that they may have a much

more Gestaltic view of sound fields.

62RO optimistically pointed out that the room was "Even, top to bottom." Again, the idea is presented that

perhaps singers do not need a lot of feedback, so much as they need consistency across direction and fre-

quency.


+ Pulled back at the first sign of danger

RB6: "I pulled everything back -- sound, intensity, volume"

JP5: "I had to concentrate not to push and stay relaxed"

CF8: "I didn't this time ... I just rolled with it"

- Didn't adjust

RO11: "I did [sic] really adjust at all"

- Increased

CF1: "I sang loudly"

WM10: "Over accent syllables"

A majority of the singers seem to reach a point where they are aware of some sort of vocal peril that is

imposed by the environment in which they are singing. A good topic for further study would be deter-

mining at what point singers decide that the environment is hostile, and to simply "roll with it." It is a

safe assumption that the acoustics in some halls fall right on the dividing line, in which singers are un-

aware that there is anything wrong with the acoustical support their environment is providing, but in

which their voices are at extreme risk.

CF also points out that she held her phrases for longer periods, again trying to create artificial reverbera-

tion by simply extending her notes. She also points out that that technique makes expression

63very difficult. However, she changed her technique in CF8.

If you could change one specific property of this environment to make it better, what would it be? Why

did you choose that particular property?

+ Liveliness

RB6: "Liven it up -- I need to hear something coming back"

CF1: "Make it more lively"

CF8: "Make it more active, more lively"

+ Reverb

WM1: "Reverb"

WM10: "Reverb, so I don't have to shout"

Obviously the anechoic environment is an extreme case in room hostility. The author originally was not

going to include it, but upon further thought, it seemed wise to include a logical extreme in the changes

in parameters--a reference point, or acoustical "absolute zero," to find out the effects of no environment

on singers.

This points out an interesting angle for more research. This study is subtractive in nature. That is, it be-

gins with a "standard environment" that has some presence, and certain characteristics are removed to

produce an effect. It may be more revealing to start with an anechoic environment, taking an additive

approach, as it might provide more insight into what singers really need from environments, and would

give a good idea of the dividing line between the realization of danger and the range of vocal peril that

was mentioned in the previous section.

64The singers' response to the anechoic environment also suggests that, since it is a good reference point

for acoustic absolute zero, it might be a good idea to begin every session in this environment, have the

performers begin singing, then to turn on the actual artificial environment. This would allow a "reset-

ting" of the singer's sense of environment, rather like drinking water between wine tastings.


+ Small, enclosed spaces

RO11: "Small practice rooms"

WM10: "closet"

RB6: "closet (with lots of winter coats)


Responses were generally not positive. RB says, "Yuck! No movement or energy." That just about de-

scribes the environment.


ing [including momentary vocal glitches]?

+ Forgot words

WM10: "I forgot some of the words in 'Star Spangled Banner' having to scream"

WM1: "forgot words" [WM had sung the SSB more than 40 times before]

+ Pitch problems

CF1: "I couldn't keep my pitch"

JP5: "I found the pitch was harder to maintain. I sometimes felt the pitch was about to change"

65WM seems to have a problem with performance nerves. In really poor environments (consistently), she

forgot the words to the Star Spangled Banner. Apparently acoustics can throw off more than just the

sound of a performance.

More interesting is the agreement between CF and JP that their pitch suffered in the environment. This

suggests that singers may use reverberation as a sort of "pitch memory," in the same way that people use

repetition to remember telephone numbers. As their performance returns to them in a reverberant envi-

ronment, they use that returning sound to launch them into their next pitch. This very strongly suggests

an experiment with very subtle pitch changes in the reverberation of an artificial environment.













How would you rate this environment overall?


66Finally, we see agreement from all of the singers. It is interesting to note that, although the singers de-

scribed the environment as being completely non-reverberant and non-resonant, they still found it re-

sponsive--suggesting that, as long as they can hear the sound of their voices coming directly from their

mouths to their ears, they can still perform.

Environment 7: "Fan Room"

Standard settings, plus CP1 SHAPE Fan. Understanding the SHAPE parameter of the CP1 effects pro-

cessor requires a brief explanation of the way the CP1 operates, internally. When the CP1 receives a

sound at its inputs, it divides its response to the sound into two pieces: an early reflections stage and a

reverberant "tail." The early reflections stage applies to the first few dozens of milliseconds of reverber-

ation, and consists of many distinct repetitions of the original sound--representing reflections from dis-

tinct surfaces--at varying low volume levels, sent to the six different output channels. This approxi-

mates the response of a real room to the sound. At the end of the early reflections stage, the CP1

smoothly transitions into the reverberant tail, which is more diffuse. The SHAPE parameter affects only

the direction and number of reflections returned by the CP1 during the early reflection stage. The rever-

berant tail is left alone.


+ Headroom

JP3: "Responsiveness"

RB7: "Brilliance in the top range"

- Environment was perfect

RO7: "Not anything -- I felt happy and calm"

CF2: "Not much -- I was very comfortable"

67CF13: "It had everything ... 'cept subtlety"

Overall, the singers seemed to think that the FAN SHAPED setting was much more natural, and more

friendly, than the RECTANGULAR setting. The study was originally supposed to have the CP1 set to

FAN all the time, but a clerical error with RB's first trial made that impossible -- the CP1 had reset to

RECTANGLE, and the author was faced with either having to start RB back at the beginning of the ses-

sion, or accept RECTANGLE as the default early reflection setting.

The "perfection" of the setting described above seems to be completely divided along the line of gender.

It would have been desirable to have more subjects, so that true statistical significance could have been

established regarding the preferences of singers of certain ranges for certain parameter settings.


+ Reverberation

JP3: "Reverberation"

RB7: "Reverb"

CF2: "reverb. I could hold notes as long as I wanted without the room dictating it"

RO notes that this environment had "plenty of room without being too live." This verifies the findings

of the many studies that have determined the importance of the placement of early reflections on the de-

sirability of certain settings. This is another topic area that could be expanded into an entire study of its

own.


+ Attempt to not become overzealous

RB7: "I tried to fill the space without over-singing"

RO7: "I had to be careful not to push ..."

CF2: "I was more dynamic and let the room carry the sound"

Other comments were interesting, including JP's idea of "concentration, fall back on feeling," and WM's

idea of "adding more [vibrato]" to her voice.



+ Don't change it

RB7: "I wouldn't change much"

CF2: "I don't think I'd change anything"

RO7: "I wouldn't change anything"

There was no meta-statistically significant correction suggestion, which seems to indicate that this is the

most desirable environment of the ones used in this survey. One likely explanation: the FAN shape is

more natural to a singer's ears than a RECTANGULAR one. This may deal with the direction, the num-

ber, or the spacing of early reflections. Although WM mentions a "dead space" to her sides, the author

is unsure what the difference is between the early reflection patterns produced by RECTANGULAR and

FAN. The only definitive conclusion that can be drawn is that something about the early reflections pro-

vided by FAN is preferable to those provided by RECTANGULAR.

69Does this setting remind you of any halls you have sung in, or listened to music in, before?

+ Cathedral

RO7: "Large stone Catholic churches as opposed to Protestant wooden churches. Cathedrals

where all the surfaces are hard"

RB7: "Stone church setting -- lots of marble and high ceilings"

The significance of RO and RB agreeing on an exact setting can not be overemphasized. Not only do

they both agree that this setting has stone walls, they agree that it has high ceilings! This specificity sug-

gests that this is indeed the most realistic environment, and it could very well be that some vertical di-

rectionality has found its way into the early reflections--that is, a sonic illusion that the singers are re-

ceiving reflections from floors and ceiling.

This brings out two ideas: first, further study should be done into the differences between the FAN and

RECTANGULAR settings on the CP1. Second, and more importantly, future studies like this one,

which use artificial environments, should include the third dimension when studying directionality pref-

erences.


All of the singers had positive things to say about an audience's response, except for JP, who remarked

that they would rate him as "strained." Perhaps he was the only user of the environment to reach satura-

tion of the system.


ing? + Vocal weakening

WM12: "my voice was a little weak, but this acoustic environment wasn't bad"

70CF13: "Tired. Yukky. Not good quality at all"

RB7: "Tight in the top -- voice is getting tired"

JP3: "Pushing for high note"

Could this environment be deceptively good? It seems almost as if, in the tenors' low ranges, the envi-

ronment holds much promise, but as soon as they begin to sing higher, they come up against a brick wall

-- again, this may be due to saturation of the equipment.

This is a good point to note that seven trials (which translates to 21 songs) seems to be the point at

which singers become uncomfortable with singing any further. This could explain the "tiredness" factor

in all cases except JP3. However, it presents the point that future studies should reduce the amount of

time that singers spend singing straight through, and perhaps should concentrate on finding a larger

number of singers to compensate.











71How powerful do you feel in this environment?




Again, the statistical significance of these numbers is questioned, for several reasons: first, certain envi-

ronments were rated twice by performers who tended to rate settings high, and others were rated twice

by performers who tended to rate settings low. Some sort of statistical adjustment might make these

numbers more informative. Second, it is possible that, as singers discovered what the truly bad environ-

ments sounded like, they tended to overrate the good ones, meaning there is some time-variance in their

rating scheme. This should be somehow planned or in future studies--perhaps by not doing any numeri-

cal study at all, or by making a more fixed set of criteria for rating the settings.

Environment 8: "No Sides"

Standard settings, plus Side amplifier (MT600) turned off. This setting was designed to have less lateral

energy than the other settings, to test the effects of directionality on singers' response.


+ Low response

JP2: "Seems to be missing bass"

WM5: "When I used my lower range, I could not hear any reverb"

+ Reverberation

WM5: "A little reverb"

RO8: "I think it lacked some reverb. I don't think I would have sung as big if it didn't. I felt my

72voice getting trashed in the upper notes of my selection"

+ Not enough acoustical "space"

RO2: "I felt like the top notes didn't have enough room to bloom"

RB13: "The setting lacked expansiveness -- the sound did not blossom"

Again, it is interesting to find that RO and RB used the same terminology without realizing it. Although

missing low support was a running theme among all of the environments, "blooming" and "blossoming"

seem to have become an issue only when the side speakers have been cut off.

Because theatrical and musical stages are usually less deep than the hall they open into, it is possible that

singers are used to hearing most of their early returns from in front of them. The idea of "blooming"

could be explained by the side returns becoming larger over time as the singer "fills" the hall.


+ Reverberation, resonance

WM5: "Reverb in the high range for voices"

CF10: "Reverb and resonance -- it was a comfortable setting"

RO8: "It [had] wonderful fast resonance. I could sing big without pushing"

RO2: "It felt kind to my middle and upper range"

RB13: "It didn't lack reverb or resonance"

The singers seem to be contradicting themselves, as to whether there is enough reverberation present in

this setting.

73Off the record, several of the singers made comments about this setting that led the author to believe that

too much return directly to the sides of a singer can hamper a singer's performance. Interestingly, this is

the opposite of what audiences prefer, as seen by Dolby Laboratories' success with Surround Sound,

which includes the addition of speakers to the sides of the audience to envelop the listener in the sound

coming from the front speakers.

It would seem that singers are not comfortable being enveloped by their own voices, while audiences are

very happy to be enveloped. Although RB's comment about needing more "room" could very well be a

request for more side returns. This particularly reinforces the statement that was made earlier about

delving further into the effects of directionality on singers' responses.


+ Don't adjust

JP2: "Again, I try not to adjust. It's bad news to adjust"

CF10: "I didn't adjust anything -- I'm pooped"

+ Avoid Darkening

WM5: "I had to sing with a medium force in my lower range, so it didn't sound gutteral"

RO2: "I think I relaxed a little"

- Darken

RO8: "I had to sing darker"

All of the above comments seem to indicate individual preference, rather than an overall trend toward a

certain type of response to this environment.

74If you could change one specific acoustical property of this environment to make it better, what would it


+ More reverb

WM5: "Add a slight bit more reverb. I sounded throaty in the lower ranges"

RO8: "For art song + some oratorio I would ... put in some reverb"

Three answers which are worth comment, which were not mentioned by more than one performer, come

from RB and RO. RB restates that he would "give it more room." RO mentioned that she thought this

setting would be perfect for opera. This may be because of the 'stage' effects mentioned above. RO also

brings up a new point, saying "I would enhance whatever makes it possible for the singer to hear him-

self/herself as the audience might be hearing it." RO had commented previously that this setting seemed

to give her a "little bit of what I must sound like to an audience listening." This could be a function of

directionality, or could even be a fluke, but the underlying idea--that singers would like to be able to

hear themselves as the audience is hearing them, and thus enhance their ability to give a near-perfect

performance--should be looked into.















The most interesting results from this iteration were not numerical, but were qualitative, stemming from

RO's comments about this environment being "perfect for opera." Her comment reiterates what all pre-

liminary literature searches on ideal acoustical conditions revealed: different genres of music tend to

have different acoustical needs. Ideally, then, singers should always sing in adjustable environments, so

that they can tailor their environment not only to their needs, but to the intrinsic needs of the genre of the

music being performed.

Environment 9: "Reversed"

Standard settings, plus Main channels feeding rear speakers, Rear channels feeding front speakers. This

setting was also designed to test directionality effects.


+ Resonance

RB9: "The setting lacked resonance although somewhat reverberant"

RO10: "It needed a little more resonance for the high notes"

76RB and RO are noticing that they are no longer getting non-delayed, direct feedback of their voices from

in front of them. Although this feature (which is an artifact of the CP1's design for use with home the-

ater systems) seemed artificial to them at first, now they seem to miss it, and associate it with resonance.


+ Surround Sound

CF3: "Surround Sound -- I noticed it more when I was speaking, actually"

RB9: "I was noticing sound from different areas (side and rear)"

Again, the singers have fallen into stressing the point that a performance can be affected by directional-

ity of acoustical feedback: if it was worth mentioning, then it must have an effect.


+ "Easy?"

CF5: "I relaxed and took it easy. The room could do some of the work"

RO10: "... sing more easily"

It is possible that, because the majority of the singer's voice (the non-processed, non-delayed return) is

coming from behind the singer's head, CF and RO are perceiving it as part of their own vocal produc-

tion. This leads to an interesting question: should vocal reinforcement systems, which are used to am-

plify a singer's voice in large halls so that all members of the audience perceive it at acceptable volume

levels, broadcast their reinforcing signals behind the head of the singer they are reinforcing? This sug-

gests some intriguing product research.

77How would you critique your performance in this setting? What mistakes did you catch yourself ...

+ Tired and flat

CF3: "OK -- my throat is tired. I'm cracking more and going flat on the top notes"

CF5: "I was flat"

RB9: "Tight & tired -- clutches and grabbing due to tiredness" [RB also mentions, in response to

How do you think you adjusted: "I was aware of intonation problems -- (perhaps setting,

perhaps tired voice) and tried to adjust by not listened too closely to the sound"

For some reason, this environment seems to be consistently producing intonation problems. Despite that

it is exactly the same as setting one, simply reversed, the reversal has really caused troubles for the

singers. This could be the result of several phenomena: perhaps the singers have grown so used to the

solid frontal feedback, that they can not keep themselves in tune with less. Another theory, based on re-

search which shows that pitch perception changes with volume, is that the high volume of their rein-

forced voice causes their sense of pitch to be thrown off.















Environment 10: "Sides Only"

Standard settings, plus Front amplifier (D-75) and rear amplifier (MT2400) turned off. This setting, like

settings 8 and 9, is also designed to test directionality effects.


+ Feedback of some sort

JP1: "Overall, it lacked feedback. I was missing much of the richness of the tone"

RO5: "Enough acoustical resonance"

WM6: "All reverb, my voice was swallowed up"

+ Specifically, frontal feedback

RB10: "It lacked a sense of forward sound -- ... there was little resonance or reverb"

CF9: "Front sounds. I heard a lot from sides and not much from the front at all. It wasn't

pleasant to sing here -- it was distracting"

All of the singers noticed that something was missing, but only two realized that it was a lack of sound

coming from the front and rear. In comparing this to the "no sides setting," it becomes apparent that

2although feedback from the sides is desirable, singers do not miss it if it is gone. Front/rear feedback is

missed specifically by two of five singers, and indirectly by three of five.


+ Sing lighter

RO5: "I sang much lighter. I really had to pull back on the upper range"

- Sing louder

WM6: "I feel I had to sing much louder and stronger to be heard"

JP1: "My technique and schooling rely on not adjusting to feedback but relying on feeling alone.

If I did react I would think I would try to push more air, more volume. But I try not to."

+ Trouble with placement

JP6: "balancing of head and chest was very hard"

CF9: "it was difficult to do anything in here"

RB10: "I tried not to fight the room -- allowing the sound to go where it would"

The singers are genuinely having problems with the uneven directionality of the room. Without more

research, an absolute determination of the importance of each direction can not be made.

If you could change one specific acoustical property of this environment to make it better. . .

+ More reverb

WM6: "More reverb -- sounds horrible"

RO5: "I think more reverberation. I could use more color in my voice"

JP1: "I would like more feedback"

+ Give some evenness side/front

3CF9: "Axe the side sounds"

RB10: "I would allow for forward expansion of sound"

JP1: "I would like more feedback"

Although the singers are voicing their desires differently, they all seem to be voicing the same idea: they

want frontal reverberation. JP's comment is particularly interesting because he does not seem to know

what specifically is missing, but he knows that he wants more of something.


+ Places with soft features

JP1: "It has a certain 'deadness' that feels like an open space or a pillow in front"

WM6: "My bedroom"

RO5: "Recital halls ... with thick chairs"


+ Doubt as to whether the audience could even hear

RB10: "Where did the sound go? It never really reached me ... "

CF9: "It felt like there was nothing in front of me -- would the audience even hear me?"

JP1: "If they are in a direct line they might not think it too bad"

These comments echo RO's desire to hear exactly what the audience hears. They reveal a singer's mis-

taken impression that if (s)he hears something on the performance platform, the audience is hearing the

same thing. Previous research has shown that this is absolutely untrue, although singers would love to

perform in environments in which it is true.

4How would you critique your performance in this setting? What mistakes did you catch yourself mak-

ing? + Tired, couldn't "get into" singing

RB10: "Full sound but tired, tried to vary vowel placements"

RO5: "Not very exciting -- or dramatic but healthy to a certain extent"

WM6: "Horrible -- I couldn't get into singing -- I became careless about the quality of my voice"

All of these answers stress the importance of frontal feedback for a singer. They also suggest that a

singer's energy level in performance may be affected by the room's return, in the same way that the audi-

ence is emotionally affected by the singer's performance. A room may act as not only as a "pitch mem-

ory," it may also act as an "emotional memory," maintaining a singer's energy.















5ANALYSIS, PART TWO: PERFORMER BY PERFORMER

This section explores the correlation between the opinion of a singer for his own performance, and the

impressions of impartial listeners. Recordings of the singer's performances were played back through a

high fidelity system to a panel of three musicians. The recordings were unprocessed--that is, the rever-

beration effects produced by the CP1 in the original experiment were not recorded directly. The listen-

ers were asked to fill out a questionnaire about each performance while listening (which can be found in

Appendix 8). This section presents a comparison between the impressions of the musicians, which are

described in the previous section, and the impressions of the listeners as written on the survey sheets.

The method of analysis for this section is very different from that of the previous section. It is an unfor-

tunate fact that the questions the performers answered regarding their performance were not the same as

the questions which were given to the impartial observers. Because of this, objective, statistical compar-

ison of the singers' impressions to the listeners' impressions is almost impossible. Instead, a more

Gestaltic approach was used.

Each singer's data is presented alone, sorted by room setting. The letter/number code in the header for

each section, of the form XX#(#), denotes the singer's initials, the trial number for that particular singer,

and the room setting used for that trial.

Presenting all of the data from the singer's survey sheet would be redundant, because that data was al-

ready presented in Section One. Instead, focus is placed upon the two most relevant questions to this

section: "How do you think you adjusted, in order to sound your best in this environment," "How do you

think a member of an audience would rate your performance in this setting," and "How would you

6critique your performance in this setting." Along with the answers to these questions, each section lists

the non-numerical impressions of the listeners, in response to the question "What vocal adjustments /

performance characteristics make this performance different from all or some of the other perfor-

mances? Any other comments?"

Once the answers to these questions have been presented for all thirteen trials, all of the numerical data

from the singer's survey sheet is presented in a graph, along with a graph of the numerical data from the

listeners' survey sheets. Note that the singer's impressions have been inverted--that is, the results have

been subtracted from 100 to yield a "best-to-worst" graph, rather than a "worst-to-best" graph. A com-

parison of these two sets of graphs, combined with the non-numerical data, will verify whether the

singer's impressions of his or her performance correlate with the impressions of the objective set of lis-

teners.

Because of time limitations, it was only possible for the impartial listeners analyze two of the five sets of

performances: RB and RO. WM's performances were analyzed up to WM3, so the data has been ana-

lyzed up to that point, and the remaining ten performances have been left blank.

7Performer 1: RB

RB1(1) Listeners' Impressions for "Standard"

's'es are overpronounced

Struggling pitch -- generally flat

Forced

Struggling to get abreast of the piece -- voice out of head

Struggling to get on top of piece

RB1(1) Singer's Impressions for "Standard"

When I noticed a decrease of reverb or resonance in the upper range, I tried to back off the sound

Sound was not balanced -- top notes were thin.

Breathing was inconsistent -- phlegm in the throat.

RB5(1) Listeners' Impressions for "High Enhanced"

's'es better

'h'es finding their way into vowels

"Ramparts" and "Glare" odd style

Pitch Sounded Better

Very good

Pushing on sustained notes

More energy, more dramatic, excited

Too much weight in voice

RB5(1) Singer's Impressions for "High Enhanced"

I tried to let the voice fill out -- both top and bottom

Pleasing -- well balanced

8The top notes are getting tight -- I need to back off and free them

RB4(2) Listeners' Impressions for "High Enhanced"

"Air" was cut off funny

Gasps

Better than previous

Happy

A lot better

Life in sound (energy)

Oversinging (dramatic?!)

Not placing voice high enough in head

RB4(2) Singer's Impressions for "High Enhanced"

I opened the voice up -- full throttle

Very exciting (powerful) clear diction

Perhaps I oversang -- let the voice go too far -- breathing was inconsistent in Amor Ti Vieta

RB2(3) Listeners' Impressions for "Most Live"

Sounded more relaxed (easier to listen to)

Took more time

Smoother

Promising beginner, but generally off

Timbre changed on sustained notes -- uncomfortable

Start of ATB sounded like trouble

RB2(3) Singer's Impressions for "Most Live"

9I tried not to oversing the top

The voice was tight -- did not project fully

Tight -- lack of freedom in the top -- slight crack in Amor Ti Vieta

RB8(3) Listeners' Impressions for "Most Live"

Very trebly

Breathing stuck out

Tired

RB8(3) Singer's Impressions for "Most Live"

I tried to fill out the bottom a bit more to compensate for the brightness in the top

Very bright sound -- crisp and clean

Tired and tight in the top -- changed breath spot in SSB [ed. Star Spangled Banner] and couldn't

sustain phrase ("Banner yet wave")

RB11(4) Listeners' Impressions for "High Inhibited"

Sounded like he was concentrating on pitch

Very tired

Tired

RB11(4) Singer's Impressions for "High Inhibited"

I tried to hold back and not over-power the space (not too effectively)

Sound was uneven

Uneven in places--different vowel placements and breathing were used to offset tiredness

in the voice

10RB3(4) Listeners' Impressions for "High Inhibited"

Enunciation problems on "oh" and "broad," 's'es

Timbre change on sustain

"Through" was weird

"Land" sounded like "lahand" in Star Spangled Banner

Liked Amor Ti Vieta better

Overall depressed/depressing

Generally OK

RB3(4) Singer's Impressions for "High Inhibited"

I pulled the sound back -- reduced volume and intensity

Not thrilling or memorable

Inconsistent resonance -- slight cracks from time to time

RB12(5) Listeners' Impressions for "Less Presence"

Very tired

Some nasal diction

Fatigue

RB12(5) Singer's Impressions for "Less Presence"

I tried not to let the sound spread -- I tried to keep it focused

Uneven -- bland

Inconsistent -- vowels and breathing are not consistent due to vocal wear and tear

RB6(6) Listeners' Impressions for "Anechoic"

Really bad (tired)

11Everything in place -- timbre & quality even (good!)

Better pitch

Most aware of real music (best version of Amor Ti Vieta so far)

Relaxed

Generally Even

RB6(6) Singer's Impressions for "Anechoic"

I pulled everything back -- sound, intensity, volume

Yuk! No movement or energy

Lackluster -- tired -- tight in the top, glottal clutch at the end of Amor Ti Vieta

RB7(7) Listeners' Impressions for "Fan Room"

Very uneven timbre caused pitch shifts

More presence (room)

Shifting placement on long notes

Tired vocal chords

RB7(7) Singer's Impressions for "Fan Room"

I tried to fill the space without over-singing

Very convincing -- full sound

Tight in the top -- voice is getting tired. A few clutches from time to time. Breathing

is inconsistent.

RB13(8) Listeners' Impressions for "No Sides"

Tired, losing breath, affects everything

RB13(8) Singer's Impressions for "No Sides"

12I tried to focus the sound

Tired.

Tired and inconsistent. Top is weak and thin. High note in Amor Ti Vieta was strained

and forced.

RB9(9) Listeners' Impressions for "Reversed"

Trebly

TIRED (not voice -- Ray himself)

Too bright

SATB is relaxed, on top of things, moving

In right vocal place (tired, taking weight out, lighter)

RB9(9) Singer's Impressions for "Reversed"

I was aware of intonation problems (perhaps setting, perhaps tired voice) and tried to adjust

by not listening too closely to the sound.

Inconsistent

Tight & tired -- clutches and grabbing due to tiredness

RB10(10) Listeners' Impressions for "Sides Only"

Much more energy at ends of phrases

Tired seems to help his style

RB10(10) Singer's Impression for "Sides Only"

I tried not to fight the room -- allowing the sound to go where it would

Where did his sound go? It never really reached me ...

Full sound, but tired. Tried to vary vowel placements.

13

Graph 1: RB's Vocal Glitches Totals

5

1 0

1 5

20

14

5

1 0

1 5

20

Graph 2: RB's Breathing Glitches Totals

Graph 3: RB's Pitch Trouble Totals

1 0

2 0

3 0

15

Graph 4: RB's Enunciation Problems Totals

5

1 0

1 5

Graph 5: RB's Style Glitches Totals

5

1 0

1 5

Graph 6: RB's Opinions [100% - X] (Darker: "How Powerful..." Lighter: "Overall")

50

100

Ana

lysis

16First, it should be noted that overall, RB had more vocal glitches than any other kind. This is probably

because the "vocal glitches" category contains the largest number of possible problems, including vocal

pops, phlegm, cracks, hoarseness, and so on.

There is a variety of ways that the above graphs could be interpreted. This paper summarizes the set of

performances in terms of whether the evaluator graphs (graph 1 to graph 5) follow the same contour as

the singer graph (graph 6), and points out the sessions for which the contours vary. This comparison can

be found in Table 1. Alternate methods of analysis are left to the reader.

Generally, a glance at the Table 1 shows that RB's impressions of his performances follow the same con-

tour as the impressions of the listeners, although the scale of the changes is exaggerated. This is due to

discrepancies between the structure of the singer surveys and the evaluator surveys, which is discussed

later in this paper.

In some cases, the contours of the two sets of graphs differ greatly. In general, RB's performance in set-

ting 6 ("Anechoic") was equally as good as his performance in setting 7 ("Fan Room"). Yet he felt

much better about his performance in 7 than in 6. He also thought set 6 was worse than set 5 ("Less

Presence"), when in fact the opposite is true. His mistaken impression about performance 7 may arise

from a "rebound" effect, or a period of recovery, from setting 6. This suggests that previous settings

may have a profound effect on the perception of current performance. He also did not feel very good

about his performance in setting number 10 ("Sides Only"), which was rated quite well by the objective

listeners. Perhaps the unnaturalness of having sound returning only from his sides made him uneasy. It

is also possible that fatigue played a factor in his impressions of his performance.

17Did much worse than thought

Did worse than thought

Follows con-tour

Did better than thought

Did much bet-ter than thought

"Standard" VBPES"High Enhanced" B VPS"Most Live" VBPES"High Inhibited" VBPES"Less Presence" VS BPE"Anechoic" V B PES"Fan Room" V BPES"No Sides" B E VPS"Reversed" VBPES"Sides Only" VBPES

Table 1 - Comparison of RB's Opinions to Evaluators' OpinionsV = Vocal Glitches, B = Breathing, P = Pitch, E = Enunciation, S = Style

18Performer 2: RO

RO1(1) Listeners' Impressions for "Standard"

Not enough space to the sound

Voice doesn't have enough room particularly in lower range -- sounds thin + dry

Too fast

Good dynamic control

Had a hard time understanding what was sung

Notes slid near the end

RO1(1) Singer's Impression for "Standard"

I held back a little

Blah

Mediocre. I didn't really think about breath support. And I could have been more musical--

alot more--especially using louds + softs.

RO6(1) Listeners' Impressions for "Standard"

Shifting positions top to bottom

A bit oversung

Consonants better / some [unint.]

Sibilance again. Very "trebly" in high register

Very few "d's" came across

RO6(1) Singer's Impressions for "Standard"

I brightened the sound -- I felt that improved the pitch.

Depends on audience. Members of big-country-low class-uncultured but real nice friendly +

warm--would like this kind of singing.

19Piggish. I used to think this was a good environment for me -- but now I think that I kind of sing

like a pig in it.

RO9(2) Listeners' Impressions for "High Enhanced"

All but upper notes too bright

Most of it caught on end of soft palette [sic]

More legato

This was the tightest sound

Good dynamics -- good musically -- except ringing piano

Sound tired

Sounded too tired, almost sluggish

Harsh "th"

RO9(2) Singer's Impressions for "High Enhanced"

Darkened the quality. i.e., more room further back in my mouth.

For patriotic stuff -- very good.

The "America the Beautiful" was better than the Star Spangled Banner because I darkened the

sound but I think both were very good. The art song was decent.

RO12(3) Listeners' Impressions for "Most Live"

Top notes too dark

Cut off w/throat

RO12(3) Singer's Impressions for "Most Live"

I had to back off my middle register.

Pretty good.

20RO4(4) Listeners' Impressions for "High Inhibited"

Changes in vocal position 1/3 through

Hard consonants weak

RO4(4) Singer's Impressions for "High Inhibited"

I had to think of my technique more.

I don't know -- that's the problem.

RO13(5) Listeners' Impressions for "Less Presence"

Stuck just low of placement but very even quality all the way through

Too Italian

Ends of notes -- probably fatigue

Piano -- tinny

RO13(5) Singer's Impressions for "Less Presence"

I had to darken the sound and lower the breath. I also probably pulled back a bit.

Pretty good.

A little pushed.

RO3(5) Listeners' Impressions for "Less Presence"

Good -- more controlled

Notice "scooping"

Lovely sounding until gutteral notes at the end [of chosen piece]

RO3(5) Singer's Impressions for "Less Presence"

I tended to push some -- I tried not to after a while.

Pretty good -- I almost forgot the words in America the Beautiful.

21RO11(6) Listeners' Impressions for "Anechoic"

Too bright + shallow vowels

Obvious tried to brighten to keep pitch up -- but because not high enough placement pitch is still

not quite on

Stuck in low vocal position / only burst of energy gets it a little bit into correct position.

Some scooping up to pitch

RO11(6) Singer's Impressions for "Anechoic"

I did[n't?] really adjust at all.

Pretty good.

Pretty good -- to very good.

RO7(7) Listeners' Impressions for "Fan Room"

Stuck in a low position more forward

This was the most below the correct placement.

Consonants better

Funny sounds -- Feedback? Don't like trebly sound.

Most "musical" (moving) version.

RO7(7) Singer's Impressions for "Fan Room"

I didn't have to [adjust] too much -- I had to be careful not to push but I think that was more the

fault of the accompaniment being too present.

Very high -- they often do.

Good. I was a little thrown by the accompaniment.

22RO8(8) Listeners' Impressions for "No Sides"

Using throat to cut off some notes

Placed very high even up + down

This was much more even top to bottom with regard to timbre + quality.

Clean sound

Piano -- strange sound

Very carefree rendition [of America The Beautiful]

RO8(8) Singer's Impressions for "No Sides"

I had to sing darker.

For opera -- very good. Lighter stuff overblown.

Good but better when I pretended that I was singing opera -- especially in America the Beautiful.

The art song (my selection) I was in danger of trashing my voice.

RO2(8) Listeners' Impressions for "No Sides"

Changed approach 1/3 through

Tendency to scoop up to note

More clarity & good pitch. Sibilants more noticeable.

Clarity but s's a problem

Sounded more relaxed than the first version

Was able to understand more clearly

Sounds like she had a lot of trouble breathing.

RO2(8) Singer's Impressions for "No Sides"

I think I relaxed a little and listened to myself more.

Pretty good.

23I just think I could do everything more especially sing with longer line.

RO10(9) Listeners' Impressions for "Reversed"

Stuck on soft palette [sic]

End consonants not always accurate

A very tight sound.

Sounding tired.

Present

RO10(9) Singer's Impressions for "Reversed"

I had to pull back + darken some -- sing more easily.

Pretty good -- I pushed at times.

RO5(10) Listeners' Impressions for "Sides Only"

Slipped out of position a little bit

More presence

More presence of the voice

RO5(10) Singer's Impressions for "Sides Only"

I sang much lighter I really had to pull back on the upper range.

It would depend on the audience. A real opera audience would probably boo you off the stage.

Whereas an "earlier than thou" pretentious recital audience would probably find it

delightfully "safe."

Not very exciting--or dramatic but healthy to a certain extent

24

1 0

20

30

Graph 7: RO's Vocal Glitches Totals

5

1 0

1 5

Graph 8: RO's Breathing Glitches Totals

25

Graph 9: RO's Pitch Trouble Totals

1 0

20

Graph 10: RO's Enunciation Problems Totals

5

1 0

1 5

26

5

1 0

1 5

Graph 11: RO's Style Glitches Totals

Graph 12: RO's Opinions [100% - X] (Darker: "How Powerful..." Lighter: "Overall")

20406080100

AnalysisAs with RB, the comparison of the contours of RO's opinion graph and the objective listeners' opinion

graph is summarized in Table 2.

Overall, RO's impressions of her performances follow very closely with the opinions of the objective lis-

teners. This is especially pronounced with regard to setting number 7, which she rates the most highly

of the ten rooms. The evaluators agree that her best performance was produced in that environment.

27Surprisingly, RO enjoyed setting number 6, which was supposed to be the worst setting for a singer to

perform in. The only area in which she did exceptionally poorly in setting number 6 was pitch, which

further suggests that singers use the concert hall as a "sounding board" to maintain their tuning and key.

Did much worse than thought

Did worse than thought

Follows con-tour

Did better than thought

Did much bet-ter than thought

"Standard" VBPES"High Enhanced" V BPES"Most Live" VBS PE"High Inhibited" VBPES"Less Presence" VBPES"Anechoic" P VBES"Fan Room" E VBPS"No Sides" BPES V"Reversed" VBPES"Sides Only" PE VBS

Table 2 - Comparison of RO's Opinions to Evaluators' OpinionsV = Vocal Glitches, B = Breathing, P = Pitch, E = Enunciation, S = Style

28Performer 3: WM

WM2(3) Listeners' Impressions for "Most Live"

Tended to slide notes a lot

Choppy beginning

Better resonance

Better presence

Consonants

WM2(3) Singer's Impressions for "Most Live"

Just sang and tried not to listen because it was too confusing

Fairly good but not great

If I listened to myself too closely, I got confused

WM3(5) Listeners' Impressions for "Less Presence"

This was much cleaner and not breathy like the other two times

Tired / PRESENT

Consonants

WM3(5) Singer's Impressions for "Less Presence"

This is the type of setting I am used to and does not take much adjusting

Pretty good

I felt fairly satisfied -- a few glitches. I feel comfortable in this setting because I could play my

voice off the walls

29WM1(6) Listeners' Impressions for "Anechoic"

Scooping - [unint.] - Pop

Tone changes in different registers

Consonants

Good voice for this song (Piece of choice)

WM1(6) Singer's Impressions for "Anechoic"

Listened to the sound of my voice coming from me, not off the walls -- of which I'm not used to

50% of what my voice shows

Forgot words. Since my sound ends once I stop singing, I needed to breath [sic] quickly so no

30dead space would occur.

5

10

15

20

Graph 13: WM's Vocal Glitches Totals (Incomplete)

5

10

15

Graph 14: WM's Breathing Glitches Totals (Incomplete)

31

5

10

15

Graph 15: WM's Pitch Trouble Totals (Incomplete)

5

10

15

20

Graph 16: WM's Enunciation Problems Totals (Incomplete)'

32

5

10

15

Graph 17: WM's Style Glitches Totals (Incomplete)

50

100

150

Graph 18: WM's Opinions (Darker: "How Powerful..." Lighter: "Overall")

Analysis

Because the objective listeners never finished listening to WM's performance set, it would be useless to

present her results in the form of a graph. However, there are some features of the limited amount of

data available about WM's performances that should be noted.

33It is very interesting that all five of the evaluator graphs follow the exact same contour: two roughly sim-

ilar performances in settings 3 and 6, and a better performance in setting number 5. WM's opinions of

the settings does not reflect this at all. Instead, WM seems to feel equally comfortable in settings 3 and

5, and uncomfortable with setting 6. It would seem, based on the small amount of data available, that

WM's opinion about an environment has little effect on her performance quality. The reverse is also

true.

It is possible that, because of WM's lesser experience when compared to RO and RB, she is not as aware

of her level of performance quality. This could only be determined through further study.

34

Conclusion-

Although there were too few participants in this survey to establish any statistically definitive answers to

the questions posed in the introduction, several interesting points did come up in the course of the analy-

sis of the data gathered which are worth noting, and which provide a solid foundation for future re-

search. Although this research did not provide any statistically significant answers about the effects of

concert hall acoustics on performance, it provides some very specific questions. That is, hypotheses

which previously did not exist in the literature.

The theme which recurs most often in the gathered data is the desire by musicians to perform in even en-

vironments. Performers prefer, and actively ask for, evenness in frequency response and sound distribu-

tion. When faced with an uneven performance environment, the singer will adjust the singing technique

to force the environment's response to be more even. In environments with frequency problems, the

singer may darken or brighten the vocal timbre. To fill directional holes, the singer may turn his head

while singing. In non-reverberant environments, the singer will hold notes for a longer period of time.

Unevenness can be particularly detrimental in environments which enhance undesirable aspects of a

singer's sound, such as breathing or vocal stops. In these cases, there is very little that the singer can do

to correct the problem. For example, a singer certainly can not stop breathing. However, despite that

logical assertion, the singer may actually unconsciously try to stop breathing, or at least to quiet the

breathing, which can result in the deterioration of a performance.

Most often, a singer's adjustment is completely unconscious, and is a natural reaction, even when the

singer is not aware that adjustment is occurring. In some cases, the singer can become fatigued, sore, or

35unmotivated without even realizing that the room is the cause. This is illustrated particularly well by

RB's situation in the "Most Live" setting, in which he responded verbally differently in his two evalua-

tions, but in which he responded physically identically. The voice reacts the same to an environment,

even if the mind does not.

There is a point, however, at which the adjustment has become so extreme that the singer can not help

but realize that it is occurring. When this "peril point" has been crossed, the singer will consciously

make an effort not to adjust. The consciousness of having crossed this point makes the difference be-

tween a singer holding back and adjusting to an environment, or singing all-out and refusing to adjust.

The peril point seems to differ from singer to singer, and seems to vary directly with the singer's level of

solo experience.

Despite their listening very carefully to their performances, sometimes singers are deceived into thinking

that they are delivering a poor performance, even when the performance is flawless. Although singers

are aware that the acoustics on the stage are not the same as the acoustics in the audience, it is impossi-

ble for them to judge their performance any way other than with their own ears. Oddly, though, the par-

ticipants in this experiment sometimes perceived the same environment very differently in different tri-

als. It is likely that these differences in perception were purely contextual. The singers' ears had ad-

justed to the sound of the previous environment, and that memory colored their perception of the present

environment.

This phenomenon is further supported by the fact that, toward the end of their trials, the singers seemed

perfectly at ease in the artificial environment that they had previously thought sounded treble-heavy and

unnatural.

Although some environments can apparently be made to sound better by comparison to others, the vocal

response of the singer has nothing to do with how the environment is perceived at the time. In other

36words, the physical response of the voice has little to do with how the singer may feel about the environ-

ment, but has a lot to do with how the singer feels in the environment. A singer may think that a setting

is relatively good, and yet may not sing well because he or she is not aware that the room is having a

negative effect.

The most interesting effect observed in this particular run of settings was the "fight or flight" reaction of

RB and CF in one of the particularly loud environments, which drove them to sing their voices raw. Al-

though the adrenaline rush resulting from having one's voice amplified and returned directly in front of

one's face can be quite exhilarating, having an excessive energy level does not make for the best perfor-

mances, and can be quite exhausting over time. Fortunately, in real-life performing environments, the

volume of the return of the hall never reaches the "fight or flight" volume level.

Some interesting results came from the use of the anechoic chamber's natural acoustics. Although some

of the performers commented on how even the acoustics of the chamber were, no performer was com-

pletely happy with its response to their voices. Their pleasure at the chamber's natural acoustics only

furthers the hypothesis that ears can be trained to appreciate any environment, even one as unfriendly as

an anechoic chamber. It was established, with all of the singers, that although performing with no return

from a room is not pleasurable, it is possible. And it is interesting to note that all of the singers were

consciously resisting the urge to adjust to the anechoic chamber, which supports the hypothesis that

there exists a point where a singer will become conscious of vocal peril, and re-adjust.

Another theory which came about because of the use of the anechoic chamber is the idea of the use of

reverberation as a sort of "pitch memory." In much the same way as human beings use repetition to re-

member a series of numbers, musicians use a hall's natural repetition--reverberation--to hold their pitch.

37In environments which lack reverberation in crucial frequency ranges, singers tend to have more trou-

bles holding on to the pitch, and tend to perceive themselves as falling out of tune. They may adjust by

holding their notes for a longer period of time. However, this adjustment causes problems with expres-

sion and artistry.

Regarding sound distribution, the singers had definitive preferences for the direction of the return of

their voice from the environment. In this six-speaker setup, the front is without a doubt the most impor-

tant source of a singer's feedback (which is logical, since human beings are visually-frontal beings, and

usually associate sounds with visual cues). Secondarily important is feedback from the rear. The sides

seem to be almost an afterthought, which is not consciously missed when it is not present, but which is

appreciated when it reappears at subtle levels.

Section Two of the Analysis portion of this paper demonstrates that singers' impressions of their perfor-

mances are, for the most part, quite accurate when compared with the impressions of objective listeners.

There are some circumstances, though, under which a performer may judge their performance as much

better or much worse than it really is. These circumstances seem to involve context more than absolute

room acoustics. For example, Room 7 seemed to be the favorite of all of the singers, yet the perfor-

mances in Room 7 were not judged as being particularly better than any of the other performances. It is

likely that because the singers were the most satisfied by Room 7, they thought their performances

would be perceived as better. The exact opposite case holds for Room 6, in which the singers did not

feel powerful or effective at all, and yet in which they sometimes delivered performances which were

comparable to their performances in Room 7. These two rooms--supposedly the best and the worst in

the set--were contextually very different from the other settings. Their difference from the other settings

were the most dramatic, and therefore the singers felt the most affected by them.

38

Fatigue also played a very important factor in the singers' impressions of their performances. A good

example is RB, who thought that his performance in Room 10, one of the last four of his performances,

was terrible. In fact, his performance was no worse than any other. Yet RB seemed to have a very

strong need for a return of his voice from the sides, while the other participants did not.

Generally, then, singers usually have a very accurate idea of the quality of the performance they are de-

livering. Each singer has a preference for certain settings, and will judge their performance based on

their comfortability level with that setting. In circumstances where the singer feels terribly about the

performance setting, the singer will almost inevitably feel terribly about the performance, even if it is

stellar.

All of these hypotheses could benefit from further experimentation to determine their validity. The fol-

lowing section, written for the enterprising acoustician, describes the problems encountered in perform-

ing this experiment, and contains suggestions on conduction of future research in this field.

39

For Future Research-

The driving premise behind this project was that, regardless of the data acquired, the project report

should be made into a guide for researchers conducting this type of survey in the future. This section

summarizes all of the problems, both expected and unexpected, that were encountered during this re-

search. It contains suggestions for new experimental procedures which may help to avoid these prob-

lems, and which could result in more conclusive data than is presented here. Suggestions for new re-

search topics are also presented. It concludes with a note about budgets and funding. It is the author's

hope that this work will inspire larger, more well-funded, more conclusive efforts in this field and re-

lated fields.

EXPERIMENTAL METHODIn conducting the experiment, a number of problems were found with the equipment and the experimen-

tal procedure which could not be fixed at the time. However, a revised experimental procedure should

take all of these problems into consideration. The result would be a much more efficient, more reliable,

more flexible experiment.

Subjects

The decision to use singers in this experiment was explained in the body of the report. However, there

are some additional notes about the use of singers which were not evident until the experiment was al-

ready underway. These points are important to any future research in this area.

The first obvious problem inherent in using singers was the need for accompaniment. Although this was

overcome with prerecorded tapes, the accompaniment playback volume was inconsistent between

40sessions, because each singer had their own accompanist record their tape. Instrumentalists would have

no such problems.

Fatigue was also a factor in the singers' performance over time. Pianists have much more endurance, be-

cause their performance involves mostly their hands and feet. Vocalists are severely limited by the du-

ration for which they can sing at full performance quality.

Although these factors could be lessened by doing fewer trials on each performer, the warmup/fatigue

curve would inevitably affects the overall performance quality over time. Although it would be desir-

able to account for this in the data analysis, with the information currently available in the literature, that

is impossible.

In future experiments, then, the number of performance sets should be restricted to six or seven, or the

number of songs in each set should be reduced. Unless the difference between a cappella singing and

accompanied singing is specifically being studied, the number of songs in a set could actually be cut to

one. In general, singers seem to be capable of approximately one hour of singing, plus brief breaks, be-

fore fatigue begins to affect mental composure and performance quality. Total warm-up usually occurs

after the first twenty to thirty minutes of singing. This leaves approximately thirty to forty minutes of

rock-solid, consistent singing time during which the performer is completely warmed up, but not fa-

tigued.

Equipment

A properly designed equipment setup can make a profound difference in the reliability of data, the com-

fort of the experimenter, and the flexibility of the experimental procedure. All of the equipment used in

this project was borrowed, meaning it was impossible to plan the environment from scratch. Although

41the equipment used in this experiment was of exceptional quality for the applications for which it was

designed, it fell short of creating a flexible, realistic artificial acoustical environment. Assuming that fu-

ture experimenters will have the luxury of choosing their own equipment, there are several equipment is-

sues which need to be addressed.

The microphone/speaker/time invariant DSP processor combination resulted in the type of high-fre-

quency enhancement that occurs when a PA system is on the edge of acoustic feedback. This caused the

singers to be quite irritated by the environments that had a lot of high frequency content by definition,

and caused every environment to sound a bit unnatural. Placing a high-impact microphone on a boom in

front of the singer's mouth would ease this problem. Such a setup would also make it possible to make

accurate loudness measurements of the singer's voice.

A lot of equipment was needed to create the environment, and the setup had to be reassembled from

scratch for each singer. Although every care was taken to make each setup exactly the same, it was im-

possible to guarantee that the equipment was set exactly the same every time it was set up. Because the

effect is random, it would be impossible to account for it in the data analysis. A permanent setup would

be desirable.

The only frequency controls in this system were the EQ controls on the mackie mixer which was being

used as a microphone preamplifier, and the internal DSP controls of the CP1. A 30-band graphic equal-

izer should be included in any system design to make frequency effect tests more subtle.

The CP1 DSP processor was designed for home theater and hi fi systems, not as an artificial acoustical

environment processor. Because of this, it feeds its inputs directly to some of its outputs, and mixes the

42processed signal on top of the direct signal. This resulted in an instant "slapback" of the singer's voice,

which could not be avoided, and also contributed to the acoustic feedback problem described above.

Further, its controls are all calibrated in terms of home theater and hi fi audio parameters, not room

acoustical parameters, which made it difficult to vary the artificial environments in terms of Gade's mea-

surement system. Use of a more appropriate DSP system is the most crucial change described here.

One piece of equipment which could be explored is a real-time auralizer. As the cost of these units

drops, it is becoming more feasible to record binaural room impulse responses with a dummy head, and

to create a "room" using a set of headphones. Because binaural techniques have trouble placing reflec-

tions in specific locations, this would make it impossible to test the effects of directionality. However, a

system like this would be much more convenient to transport and set up than a set of speakers and am-

plifiers in an anechoic chamber. For experiments that are not concerned with directionality effects, a

real-time auralizer and a pair of good closed-air headphones would be a reasonable alternative.

If directionality is a concern, with a bit of a budget it would be possible to use a Lexicon Lares system,

set up in a Wenger Acoustic Variable Environment (WAVE) Chamber. These environments are de-

signed to produce extremely realistic acoustical environments, and although WAVE chambers are de-

signed to be set up permanently, the components used in its construction are capable of parametrically

altering the simulated environment. Such a chamber is additionally advantageous because it has already

been designed. The user need only call Wenger and order one.

43Procedure

Because consistency was a very important part of gathering reliable data, it was impossible to alter the

experimental procedure once the project had begun. In retrospect, there are several techniques that

could have been used to produce better data.

Although it is beyond the scope of this report, this research suggests that the context in which a singer

encounters a particular environment affects the singer's perception of that environment. For example, it

seems that singers are relieved upon leaving the anechoic setting (setting 6), and perform extremely well

in the environment that follows it. Although contextual effects are a fascinating field for future research,

in experiments like this one they are undesirable, and steps should be taken to reduce their effect on the

data. Sheer numbers of singers would solve this problem, if each singer encountered the settings in a

different order. Alternatively, each performance session should be separated from the previous one with

a buffer period in an anechoic setting (or some other neutral environment) for the singer to warm up and

"clear the ears."

Also beyond the scope of this report is the phenomenon of ear adjustment and coloration. As the experi-

ment progressed, the singers became more accustomed to singing in artificial environments. What

seemed artificial to them at the beginning of the experiment did not seem artificial by the fourth or fifth

performance session. This could have been corrected in one of two ways: either the first two environ-

ments could have "warm-up rooms," discarded during the analysis, or non-artificial-sounding equipment

could have been used.

Also, it was briefly mentioned in the data analysis section that this survey is "subtractive" in nature. The

standard room from which every other room is derived, has some ambience. It might be wise, in future

44experiments, to use the anechoic chamber as the starting point, and to base all of the other rooms off of

that, adding one bit of ambience at a time, carefully choosing the environments such that a single acous-

tical feature is added in each one. Assuming that the results could be superimposed, this would provide

much insight into the reactions of singers to very specific forms of a hall's acoustic feedback.

Finally, future experiments should make use of a "control" group. This control could be arranged such

that each performer in the group performs in the same environment 10 times. This would allow for cor-

rection of the data based on fatigue, and would make the data analysis more conclusive.

Questionnaires

The questionnaires which were given to the singers after each performance set were very carefully de-

signed to yield a variety of data about the singers' feelings about the environments, in both numerical

and subjective terms. Because no research of this type had been done before, the sheets had to be de-

signed from scratch, based on expected results. The survey contained a large number of subjective ques-

tions, to allow the musicians to express opinions that were not expected, and thus not numerically repre-

sented on the survey. As the body of knowledge in this field increases, subjective questions should be

de-emphasized, with more attention being paid to numerically analyzable data. In these early stages of

research, the singers' subjective answers serve the purpose of providing revision information for future

questionnaires.

It was obvious in reading the musicians' answers that the questionnaires must be cleverly designed to

pull more information from the singers--to almost "trick" the singers into providing more data. It was

also apparent that the questions should have been phrased much more specifically and precisely. For ex-

ample,

45questions like "how do you think a member of an audience would rate your performance in this setting"

can be made clearer by specifying the type of audience: other singers, for example.

Also, comparing the singers' evaluations with those of the objective listeners was difficult because of the

discrepancies between the two questionnaires. The singer questionnaire focused more on evaluating the

environment, while the listener questionnaire emphasized the singer's performance. Because the focus

of the project should be the performance, not the environment, all references to the effects of the envi-

ronment on the singer should be eliminated from the singer's questionnaire. Such questions can easily

be replaced with questions about the performance. Most importantly, all of the numerical questions on

the singer's questionnaire should be on the evaluator questionnaire, and vice versa. All numerical an-

swers should be based on a percentage scale (0 - 100), with 0 always being the worst case.

Another problem arose because of the three-song structure of the performance sets. The singers were

asked to evaluate themselves after each performance session, which was a more efficient way to manage

the singer's time in the chamber. The objective listeners, on the other hand, rated each song. This

caused resulted in some ambiguity, because in some cases one particular song of a three-song set was

rated lower than the other two. In the future, all evaluations should be done on a session-by-session ba-

sis, or the listeners' individual song evaluations (now on a percentage scale) should be averaged over a

session.

Problems also arose from the inclusion of technical terms, such as "resonant" and "reverberant," in the

singer survey. The singers seemed to latch onto the terms contained in the questionnaire, and used them

to describe phenomena that had nothing to do with resonance or reverberation/reverberance. Future

questionnaires should contain no technical terms, or the singers should be provided with a glossary of

acoustical terms to study prior to the experiment.

46

Based on these observations, a revised singers questionnaire has been created, and can be found in Ap-

pendix 9. This questionnaire should yield a greater quantity of data that is more consistent, and which

can be more easily analyzed. Appendix 10 contains the revised objective listener questionnaire.

ANALYSIS

Time shortages are the enemy of data analysis. Given an infinite amount of time to break down, present,

and analyze data, it would be possible to read a near-infinite amount of information from a finite amount

of data. Given more time, more equipment, and the new questionnaires described in the previous sec-

tion, there are several measurements of interest which could be done which were not done in this report.

The intent of the author, in designing a procedure which involved singing a cappella and with accompa-

niment, was to study the effect of environment on tempo. Although the tempo data could be easily mea-

sured with a calculator and a stopwatch, there was not enough time before the due date of this report to

take tempo measurements of all of the performance sets. Therefore the study of the effect of environ-

ment on tempo is left to future research.

Another reason for the use of a cappella singing was to measure the effect of environment on pitch.

This analysis was not done because of a lack of equipment, not a lack of time. Frequency analyzers are

rather expensive, and proper pitch measurements would require digitizing the session and measuring the

pitch of specific segments at the beginning, middle, and end of each piece. This is also left to future re-

search.

One other equipment-limited measurement which could not be done in this experiment is the measure-

ment of the average volume of the singer's voice in each environment. This would require a

47high-impact microphone at a fixed distance from the singer's mouth, which would be extremely difficult

to keep completely still. Again, this will be left for future researchers.

Finally, something should be said about the method used to analyze and present the numerical data gath-

ered in this project. The method used to analyze the numerical data in this study is "meta-statistical."

That is, standard statistical analysis of the data presented here would yield a near-zero significance, and

it was decided to create a new method of presentation that would communicate a sense of possibility of

statistical significance, given a larger number of survey participants. Later, larger studies would have

more cause to use traditional statistical analysis, because a larger number of singers would produce more

statistical significance.

48

BUDGET

49The largest frustration in this project was the lack of a budget. If the author had had the foresight and re-

sources to approach sponsors, to request endowments from the WPI Humanities Department, or to seek

out corporations which would benefit from the results of this research, many of the problems associated

with inadequate funding could have been avoided.

If the project had had a medium budget ($800 to $5000), the singers could have been paid a stipend, and

would have had more of an incentive to stay through their entire session. More singers could have been

hired. An assistant could have been brought in to help acquire and move equipment. An anechoic

chamber could have been rented for an extended period of time, which would have eliminated the need

to "strike" the equipment after each session. Specific equipment, most notably a signal processing sys-

tem designed specifically to simulate rooms, could have been rented, rather than found and borrowed by

happenstance.

If the project were conducted on a large budget ($5000 to $30,000), the author could have conducted the

experiments as at least a part-time job for an extended period of time. A temporary site, independent of

a parent company, could have been set up. The DSP equipment could have been leased for an extended

period. Many more singers could have been hired, resulting in many more data points, and statistically

significant data.

It is the author's recommendation, based on this experience, that future experiments in this area should

be conducted on at least a $1000 budget. A budget proposal for a follow-up project can be found in Ap-

pendix 11.

NEW QUESTIONS

50This research suggests a number of possible directions for future research in the area of the effects of

acoustics on musical performance. Some of these areas were originally intended to be explored in this

project, before it was realized that the magnitude of the experiment and data analysis was simply too

large to fit within the scope of this project.

One parameter which was originally going to be studied in this experiment was frequency response. Al-

though the room settings did include "High Enhanced" and "High Inhibited" settings, the equipment

used to affect the frequency alteration was not as precise as would have been desirable. Further, an en-

tire project could be conducted simply to study the effects of the frequency response of a room; this

project does not even scratch the surface of frequency effects.

Another parameter which would merit its own project would be directionality. Although this project ex-

plored the effects of turning off the side speakers and front speakers, there are many, much more subtle,

ways of changing the directional response of a room. Most important among these is the study of the ef-

fects of initial reflections on performance. Not only was the project limited by the DSP equipment (the

only parameter the CP1 has that involves direction is the "Room shape" parameter, which was shown to

have a profound effect on the singers), it was limited to a two-dimensional array of loudspeakers.

Three-dimensional directional research merits a project of its own.

The idea of a warmup/fatigue curve was touched upon in the performer-by-performer analysis section of

this paper. It is undisputed that singers must warm up their voices. It is also undisputed that, after an in-

determinate period of singing, a performer will become fatigued, then exhausted, and finally hoarse. Al-

though the last two would be very difficult to study, the transition from "cold" to "warm" to "tired" is a

very interesting phenomenon which deserves a closer look.

51

Another interesting question which was raised in the analysis of the objective listeners' surveys, is

whether a singer would evaluate himself on a recording the same way he evaluates himself directly after

a performance. This could be a very valuable phenomenon to study, in determining whether the psycho-

logical effects of acoustics on a performer change his perceptions of the performance. If, for example, a

singer judged a performance as "very bad" directly afterward, but on a recording judged it as "good," it

would be obvious that the singer's opinion was profoundly shifted by the environment.

Related to this phenomenon is the idea of ear coloration. That is, the determination of whether a person

can be forced, over time, to hear a completely unnatural setting as natural--and by extension, whether a

person can be forced to hear a wretched environment as wonderful. Phrased in even more simpler

terms: of a singer same in the same setting five times, would the setting be viewed as progressively bet-

ter?

This raises a further question: does warming up involve getting used to an environment, as much as it in-

volves getting the voice physically limber?

Several times, the author has raised the question of the existence of a "peril point:" a point at which the

singer becomes aware of adjusting to a hall's acoustics, and subsequently resets the voice and refuses to

adjust anymore. Time should be spent in determining exactly where this point falls. It is likely that the

point lies in a different place for each performer, and varies with the singer's level of solo experience.

Also, in passing, the question was raised: how would a singer perform if he could not hear his voice at

all? Obviously this is an academic exercise, since bone conduction would always allow the singer to

hear

52some part of his voice, but the question brings the problems associated with poor concert hall acoustics

to its logical extreme.

Finally, it should be noted that the view of concert hall acoustics presented in this survey may be erro-

neous. It is possible that the environment in which a singer performs has no effect on the performance.

Instead, it may be possible that the combination of the present environment and the previous environ-

ment in which a singer performed may have a combined effect. The change from environment to envi-

ronment may be more important than the environments themselves. This could be easily determined,

with proper experimentation.

The above points--the relationship of warm-up to ear coloration, the idea of environmental change ver-

sus absolute environmental conditions--are truly worthy of more study. In the author's opinion, they are

more important than the search for an ideal environment in which to perform. Because if these phenom-

ena operate as hypothesized, there is no ideal performance environment. Instead, there is a very specific

regimen which a singer can follow, in warming up and in practicing, to make the most of an environ-

ment. And making the most of an environment is the very foundation of the art of performance.

54

Works Cited

Backus, John. The Acoustical Foundations of Music. New York: W.W. Norton & Company, Inc., 1977.

Beranek, Leo L. Acoustics. New York: American Institute of Physics, Inc., 1990.

Bolzinger, S., Warusfel, O., and Kahle, E. "A Study of the influence of room acoustics on piano performance." Journal de Physique IV 4 May 1994: c5-617.

Campbell, Murray and Greated, Clive. The Musician's Guide to Acoustics. New York: Shirmer Books, 1988.

Gade, Anders Christian. Musicians' Ideas About Room Acoustical Qualities: An InterviewSurvey and a Derivation of Subjective Room Acoustical Parameters. Denmark: TheAcoustics Laboratory, Technical University of Denmark, 1981.

Geerdes, Harold P. Music Facilities: Building, Equipping, and Renovating. Reston, VA: Music Educators National Conference, 1989.

Jordan, Vilhelm Lassen. "Acoustical Criteria and Acoustical Qualities of Concert Halls." Music and Room Acoustics. Ed. Royal Institute of Technology. Stockholm: Royal Swedish Academy. 114-

Lovelace, Austin C. "Good Acoustics for Music and Word." The Hymn 41.3 (July 1990) 15-16.

Olson, Harry F. Music, Physics and Engineering. New York: Dover Publications, Inc., 1967.

Roederer, Juan G. Introduction to the Physics and Psychophysics of Music. Ed. 2. New York: Springer-Verlag, 1975.

Sundberg, Johan. "Singing and Timbre." Music and Room Acoustics. Ed. Royal Institute of Technology. Stockholm: Royal Swedish Academy. 57-

55

Appendix 1 - Acoustical Measurements and Standards

Some foreknowledge of acoustical measurement and acoustical standards is assumed in the body of the text of this paper. To supplement the reader who may not be familiar with certain terms, below is an ap-pendix of terms associated with acoustical measurement. Much of this information can be found in Be-ranek's Acoustics. Those references that can not are referenced individually.

dB or decibel - means that there is a logarithmic ratio between two numbers mentioned, which is charac-terized by the term 10*log(N/M). For example, a sound pressure level N, twice as loud as sound pres-sure level M, would be said to be 10*log(2/1)=3.01 decibels louder.

Newton (N) - SI unit of force, measured in kilograms per square meter.

SI - Systeme International, or metric, measurement system. We will exclusively use MKS measure-ment, meaning all distances will be in Meters, all masses will be in Kilograms, and all times will be in Seconds.

SPL - Sound Pressure Level. This is a means of determining the 'standard' loudness of a sound. The unit of Sound Pressure Level is the dbSPL, or decibels of Sound Pressure Level, determined by the for-mula SPL = 20*log10 (p/pref), where p is the pressure of the sound being measured, in newtons/m2, and pref= 2*10-5 newton/m2 for applications dealing with measurements in air, or 0.1 newton/m2 for calibra-tion of transducers. We will use the first value exclusively in this paper, since we will be dealing exclu-sively with air measurements.

T60 - the standardized measure of a hall's reverberance, defined as "the time required for the sound en-ergy density to decay 60db, that is, to 10-6 of its original value." Note that T60 does not specify what frequency range should be measured--this is left to the measurer to clarify.

56

Appendix 2 - Letter of Invitation

Dear N,

>Individual greeting, by context<

I am currently working on a six-term, two-part project in audio and acoustics, that may, as a fortunate byproduct, improve the performability of WPI's Alden Memorial Hall. The first half of the project, which will be advised by Doug Weeks of the WPI Humanities Department, deals with performers' per-ceptions of sound and room acoustics, with a focus on musical and dramatic vocal performance.

I am writing to you because you are a recognized authority in the area of vocal performance, and I would like to invite you to be a part of the project. Should you choose to become involved, your subjec-tive observations, combined with that of other performers, would be the basis for the first half of the project, and would lead to the implementation of an electronic system that will hopefully make Alden's Great Hall a more hospitable environment in which to perform.

Your role in the project would involve some performance, and analysis of the performances of others, as they relate to the acoustics of the hall. Because all of the musicians involved undoubtedly have other time commitments, I have left the project schedule "dangling" until I hear from all of them. The time commitment will not involve more than two periods (two or three hours each) of performance and evalu-ation of the hall, and will likely fall on weekends.

This project gives us an opportunity to improve the lives of musicians at WPI--and if it works out as planned, musicians around the world. If you are interested in participating, or have any questions about the project, please contact me. I look forward to hearing from you.

Sincerely,

Tom Guyette, '95ECE/ID HumanitiesWorcester Polytechnic Institute

57

Appendix 3 - Equipment List

Califone tape deck8 channel Mackie mixer w/power cord2 Shure 57 microphones2 floor mic stands

12 RCA male to RCA male cables2 XLR mic cables1 RCA male to 1/4" cable10' power cord6 outlet power strip

RCA female to RCA male cable1/8" female to double XLR male cablecupsGallon of wateraccompaniment tapeSurvey sheets, pen, list of room settingsDA88 tapeBinaural headset & batteriesHeadphones

6 Bose 151 loudspeakers1 Bose Roommate speaker6 speaker stands1 Crown D-75 power amp1 Crown MT2400 power amp1 Crown MT600 power ampLexicon CP1 with remote and instructionsDA88 digital 8 track recorder

1 pink banana-banana snake1 10' banana-banana cable1 40' banana-banana cable4 10' BNC-BNC cables4 3' BNC-BNC cables

6 RCA-1/4" adapters4 BNC-RCA adapters4 BNC-1/4" adapters

58

Appendix 4 - Chamber Settings

#1 - "Standard" Crown D-75 on fronts, all the way upEFF LEV -13dB Crown MT2400 on rears, @15ROOM 4 Crown MT600 on sides, @12BAL Equal All CP1 gains at maxVOL -8dB 60 degree panoramaAMBIENCE Input level horizontalSHAPE Rectangle Mic pre-amp gain verticalLIVENESS 4ROLLOFF 2.9KHzPAN 28POSITION 127ANGLE 57

#2 - "High Enhanced" Standard, with high EQ all the way up, 14.9KHz rolloff.#3 - "Most Live" Standard, with LIVENESS = 6.#4 - "High Inhibited" Standard, with high EQ down, rolloff at 329Hz.#5 - "Less Presence" EFF LEVEL -20dB#6 - "Anechoic" SYSTEM/EFFECT MUTE#7 - "Fan Room" SHAPE Fan#8 - "No Sides" Sides disconnected#9 - "Reversed" Mains to rear, Rears to Main#10 - "Sides Only" Front & Rear disconnected

Record for Rebecca O'Brien, 04.18.95RO1(1) - 00:00 RO8(8) - 50:00RO2(8) - 08:00 RO9(2) - 57:00RO3(5) - 15:00 RO10(9) - 1:04:00RO4(4) - 22:00 RO11(6) - 1:11:00RO5(10) - 29:00 RO12(3) - 1:18:00RO6(1) - 36:00 RO13(5) - 1:25:00RO7(7) - 43:00

Record for Ray Bauwens, 05.04.95Room Order:RB1(2) - RB8(3) - RB2(3) - RB9(9) -RB3(4) - RB10(10) - RB4(1) - RB11(4) - RB5(2) - RB12(5) - RB6(6) - RB13(8) - RB7(7) -

59Record for Christina Freeman, 05.03.95CF1(6) - CF8(6) -CF2(7) - CF9(8) - CF3(9) - CF10(10) - CF4(4) - CF11(3) - CF5(9) - CF12(5) - CF6(1) - CF13(7) - CF7(2) -

Record for Jean-Pierre Trevisani, 05.05.95JP1(10) - JP8(1) - JP2(8) - JP9(9) - JP3(7) - JP10(5) - JP4(4) - JP11(2) - JP5(6) - JP12(3) - JP6(10) - JP13(8)JP7(7) -

Record for Extra Person, 05.0X.95 (WM)FF1(6) - FF8(3) - FF2(3) - FF9(9) - FF3(5) - FF10(6) - FF4(1) - FF11(4) - FF5(8) - FF12(7) - FF6(10) - FF13(5) - FF7(2) -

Record for Extra Person, 05.0X.95 (Never used)GG1(9) - GG8(9) - GG2(4) - GG9(5) - GG3(10) - GG10(1) - GG4(4) - GG11(3) - GG5(7) - GG12(6) - GG6(10) - GG13(2) - GG7(8) -

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Appendix 5 - Script for Introduction to the Artificial Acoustical Environment

I'm going to read this introduction so that I don't leave anything out, and so that everyone who partici-pates in this project gets the same instructions. There is nothing mysterious going on, and no surprises. This message is just for consistency. In fact, consistency is a very important part of this experiment. Although some of these instructions may seem strange, such as the directions regarding water later on, they are necessary for consistency.

The room behind that door has been fitted with equipment that makes it possible to adjust its level of re-sponsiveness from that of a hilltop in the middle of nowhere to the inside of the most reverberant room in existence, and a variety of different settings in between. It is well-lit and well ventilated, so although you will be isolated, you will be comfortable.

You will be performing in [x] different environments inside this room. Each performance set will in-clude two minutes of warm-up in any form you wish. At the end of those two minutes, a tone will sound. When the tone finishes, please recite the phrase [hand slip] "Joe took father's shoebench out, she is waiting at my lawn." This is for calibration of the microphones. The tone will sound again. The tone is tuned to A-440, and should help you fix your own sense of pitch.

While the tone is sounding, please place your guide sheet on the floor of the chamber, where you can ac-cess it at a glance. When the tone ends, please sing the Star Spangled Banner, in whatever key you wish. Sing it as though you were in a performance situation.

When you have finished singing the Star Spangled Banner, we will give you a minute to catch your breath and make whatever comments you wish for the recording. We will then start your accompani-ment tape, and you will perform the piece which you chose. Again, sing it as though you were in a per-formance situation.

When you have finished singing the piece which you chose, we will give you a minute to catch your breath and make whatever comments you wish for the recording. We will then start our accompaniment tape, and you will perform America the Beautiful. Pick the highest octave which is comfortable for you. Again, sing it as though you were in a performance situation.

When you have finished singing America the Beautiful, we will give you a minute to catch your breath and make whatever comments you wish for the recording. We will then open the door and bring you out to fill out a survey based on that room setting. We will then go through this procedure again, starting with the tone and the Joe Lawn sentence, and ending with the survey outside the chamber.

Do not worry if you miss a note, crack, run out of breath, or have any other sort of vocal glitch. That data is just as important to the experiment as the performance itself. If you have problems, keep going to the end of the performance session as well as you can. We will supply water for you to drink between performance sessions.

If you'd like, I can repeat any or all sections of these instructions for you at any time. If you have any questions that are not answered by these instructions, write them down and I will answer them after the entire session is over. If at some point you need a break, feel free to ask and we will take five to ten

61minutes. However, the reliability of the data in this experiment relies on consistency between perfor-mance sessions.

Here is your first survey sheet. Please complete all questions as fully and clearly as you can. Here is a cup of room temperature water for you to drink. The amount that you drink now must be the same amount that you drink during all of the breaks this afternoon, so please remember how much you drink, and drink enough.

[after survey] Thank you.

Now we will enter the room, and fit you with a microphone headset. Once it has been fitted, please do not touch the headset for any reason. The data in the experiment rely on the headset being in the exact same position throughout each performance. You may remove it between performance sessions.

About twenty seconds after the door closes, the tone will sound, and the performance session will begin. Make sure you place your guidesheet on the floor, where you can see it at a glance.

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Appendix 6 - Performance Session Guidesheet[Reduced to 90% original size]

PERFORMANCE SESSION GUIDESHEET

* ENTER CHAMBER

* WAIT FOR TONE

* RECITE SENTENCE "JOE TOOK FATHER'SSHOEBENCH OUT, SHE IS WAITING AT MY LAWN."

* PLACE GUIDESHEET ON FLOOR, IN VIEW

* WAIT FOR SECOND TONE, A-440

* PICK A KEY, SING THE STAR SPANGLED BANNER[PERFORMANCE CONDITIONS!]

* 1 MINUTE BREAK FOR REST/COMMENTS TO MIC

* LISTEN FOR ACCOMPANIMENT, SING THE PIECEYOU CHOSE. [PERFORMANCE CONDITIONS!]


* LISTEN FOR ACCOMPANIMENT, SING AMERICA THEBEAUTIFUL. [PERFORMANCE CONDITIONS!]


* DOOR OPENS, COME OUTSIDE FOR 5-MIN SURVEY

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Appendix 7 - QuestionnairePlease complete the following survey, which contains questions about the room setting in which you just sang. Please be as complete and as precise as you can. In answering the questions, bear in mind your needs when singing in a concert environment, and answer accordingly.

Acoustically, what would you say this setting lacked? How did you notice it?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Acoustically, what would you say this setting did not lack? How did you notice it?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How do you think you adjusted, in order to sound your best in this environment?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

If you could change one specific acoustical property of this environment to make it better, what would it be? Why did you choose that particular property?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Approximately how many times have you sung the Star Spangled Banner? _____

Approximately how many times have you sung America the Beautiful? _____

Approximately how many times have you sung your song of choice? _____

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Please answer the following questions on a percentage scale:

How friendly would you rate this environment? _____

How responsive would you rate this environment? _____

How reverberant would you rate this environment? _____

How supportive would you rate this environment? _____

How resonant would you rate this environment? _____

How powerful do you feel in this environment? _____

How would you rate this setting, overall? _____

Does this setting remind you of any halls you have sung in, or listened to music in, before?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How do you think a member of an audience would rate your performance in this setting?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How would you critique your performance in this setting? What mistakes did you catch yourself mak-ing [including momentary vocal glitches]?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Appendix 8 - Performance Evaluation SheetWhile listening to the three pieces, please tabulate the following items, and note unusual features of each performance in the space provided. If you need more space, please use the back of the sheets, and be sure to indicate what number/letter you are extending.

(1) - The Star Spangled Banner

a) Vocal glitches: 1___________________ d) Enunciation prblms1_________________2___________________ 2_________________3___________________ 3_________________4___________________ 4_________________5___________________ 5_________________6___________________ 6_________________7___________________ 7_________________8___________________ 8_________________9___________________ 9_________________10__________________ 10________________

b) Breathing glitches: 1___________________ e) Technique glitches:1_________________2___________________ 2_________________3___________________ 3_________________4___________________ 4_________________5___________________ 5_________________6___________________ 6_________________7___________________ 7_________________8___________________ 8_________________9___________________ 9_________________10__________________ 10________________

c) Pitch trouble: 1___________________ f) Other glitches: 1_________________2___________________ 2_________________3___________________ 3_________________4___________________ 4_________________5___________________ 5_________________6___________________ 6_________________7___________________ 7_________________8___________________ 8_________________9___________________ 9_________________10__________________ 10________________

What vocal adjustments/performance characteristics make this performance different from all or some of the other performances? Any other comments?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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(2) - Piece of choice (____________________)




What vocal adjustments/performance characteristics make this performance different from all or some of the other performances? Any other comments?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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(3) - America the Beautiful




What vocal adjustments/performance characteristics make this performance different from all or some of the other performances? Any other comments?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Appendix 9 - Revised QuestionnairePlease complete the following survey, which contains questions about the performance you just completed. Please be as thorough and as precise as you can. If you need more space, please use the back of this sheet, and be sure to indicate which question you are extending.

How would you describe this room, acoustically?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How would you rate your performance? _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How would you change the acoustics of this room, to make it more friendly?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How did you adjust in order to sound your best in this room, if at all?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

How would you describe this room physically (size, materials, architectural features)?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

69Please answer the following questions using a percentage scale, where 0% is the worst case, and 100% is the best.

How relaxed did you feel during this session? _____%

How energetic did you feel during this session? _____%

How satisfied are you with this performance? _____%

Please rate your performance in terms of the following criteria. Use a percentage scale, where 0% is an absolute failure and 100% is a flawless performance.

Vocal Glitches (hoarseness, phlegm, catches...) _____%

Breathing (shortness, gasps, no support...)_____%

Pitch (flat, sharp) _____%

Enunciation (consonants) _____%

Timbre (too dark, too bright...) _____%

Style (musicality, phrasing, dynamics...) _____%

How would you rate this room, if it were a concert hall? _____%

How do you think another musician would rate your performance, overall? _____%

How do you think a member of an audience of singers would rate your performance?_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Appendix 10 - Revised Performance Evaluation Sheet

While listening to the performance sets (1-10), please evaluate the performances in terms of the follow-ing criteria. Use a percentage scale, where 0% is an absolute failure, and 100% is a flawless perfor-mance. Use the extra blank space provided to note unusual features of each performance.

Vocal glitches [hoarseness, phlegm, catches...] Enunciation Problems [consonants]Perf. 1_____%__________________________ Perf. 1_____%_______________________Perf. 2_____%__________________________ Perf. 2_____%_______________________Perf. 3_____%__________________________ Perf. 3_____%_______________________Perf. 4_____%__________________________ Perf. 4_____%_______________________Perf. 5_____%__________________________ Perf. 5_____%_______________________Perf. 6_____%__________________________ Perf. 6_____%_______________________Perf. 7_____%__________________________ Perf. 7_____%_______________________Perf. 8_____%__________________________ Perf. 8_____%_______________________Perf. 9_____%__________________________ Perf. 9_____%_______________________Perf. 10____%__________________________ Perf. 10____%_______________________

Breathing [shortness, gasps, no support...] Timbre [too dark, too bright...]Perf. 1_____%__________________________ Perf. 1_____%_______________________Perf. 2_____%__________________________ Perf. 2_____%_______________________Perf. 3_____%__________________________ Perf. 3_____%_______________________Perf. 4_____%__________________________ Perf. 4_____%_______________________Perf. 5_____%__________________________ Perf. 5_____%_______________________Perf. 6_____%__________________________ Perf. 6_____%_______________________Perf. 7_____%__________________________ Perf. 7_____%_______________________Perf. 8_____%__________________________ Perf. 8_____%_______________________Perf. 9_____%__________________________ Perf. 9_____%_______________________Perf. 10____%__________________________ Perf. 10____%_______________________

Pitch [flat, sharp] Style [musicality, phrasing, dynamics...]Perf. 1_____%__________________________ Perf. 1_____%_______________________Perf. 2_____%__________________________ Perf. 2_____%_______________________Perf. 3_____%__________________________ Perf. 3_____%_______________________Perf. 4_____%__________________________ Perf. 4_____%_______________________Perf. 5_____%__________________________ Perf. 5_____%_______________________Perf. 6_____%__________________________ Perf. 6_____%_______________________Perf. 7_____%__________________________ Perf. 7_____%_______________________Perf. 8_____%__________________________ Perf. 8_____%_______________________Perf. 9_____%__________________________ Perf. 9_____%_______________________Perf. 10____%__________________________ Perf. 10____%_______________________

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Appendix 11 - Budget For Future Projects

------MEDIUM SCALE for one month of solid data-gathering------------------------------------------

DSP Real-time auralizer rental $400

Microphone, amplifier, speaker, DA88, cable rental $1000

Rented anechoic chamber, 20 days $1000

OR

Assistant for equipment setup/takedown $600

8mm video tape for Tascam DA88 $80

$50 stipend for 20 singers $1,000

Dinner for 10 objective evaluators $75

Copying costs $60

TOTAL $3215

------LARGE SCALE for two months of solid data-gathering-------------------------------------------

DSP Real-time auralizer rental $800

Microphone, amplifier, speaker, DA88 rental $2000

Cost of living for conductor of experiment $2700

Rental of WAVE chamber and space $11,200?

8mm video tape for 50 singers $200

Full 2 Hours' pay for 50 singers $4,000

Pizza dinner for 20 objective evaluators $150

Copying costs $140

TOTAL $21,190

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