SH 565- Instrumentation in Communicative Disorders

Spring ‘02

Text/Lab Books

• Text: Clinical Measurements of Speech & Voice by RJ Baken

• Laboratory Assignments: Will be handed first day of class and some addendums may be handed out in class in terms of instruction on software to be used.

Instrumentation & Concepts

• CSL- Acoustic parameters (Frequency, Shimmer, Jitter, Intensity, Formants, Harmonics, Open Quotient)

• Sound Pressure Level- Intensity

• Aerophone- Intensity, Frequency, Subglottal pressure, Airflow, Vital capacity

• Nasometer- Nasalance

• Speechviewer: Therapy for phonology, voice

Course Design

• Lectures

• Laboratory exercises

• Demonstrations

Laboratory Assignments

• Handouts in class

• Some labs will involve:

– Independent calculations

– Instrumentation to complete

• 70% of grade

Quizzes

• Quizzes will be given the presentation week

and the content of each quiz is indicated on

your syllabus.

• 20% of total grade

Presentation

• Topics are listed on syllabi with number of participants

• Some topics may be changed in advance of the day of the presentation

• All presentations have specific criteria in which to address on syllabi

• 20% of grade

Why Instrumentation?

• Speech & voice are not a product of physiological processes

• Problem in a speech system is a symptom, not a disorder (Speech subsystems effected)

• Therapy involves getting rid of symptoms

• Must change function…So, must understand system functioning

How To Assess Symptoms?

• Pinpoint abnormality by listening?

• Sometimes? Most problems lie under the surface.

• Ears not as reliable as you think!

• Perception differs from function

• Auditory system creates a whole picture and we need to assess the parts of speech.

True Assessment

SpeechAssessment

PhysicalAssessment

Structure

SomaticFunction

Aerodynamics

AcousticsPerceptualFeatures

PhysiologicalAssessment

Objectives

• How speech production measures are taken accurately.

• Understanding what your data means.

• Being able to calculate measures by hand so you understand what the computer is doing

• Than use the computer!!

Calibration

• Instruments produce outputs

• Output = numerical value that the transducer is sensing

• Calibration is the process for determining the equivalence between the output of a system and standard units of measurement– Ex. 1cm on a chart is = 0.5 cm H20

Calibration

• All instruments must be calibrated

• Even commercial instruments have to report

final values in conventional units- Need to

be periodically tested

Calibration

• Calibration begins with a known value (we measure its output in volts, etc,)

• Inject 500 ml into a spirometer and note the pen movement

• 500 ml of air causes the pen to move 4 cm

• If 4 cm of pen motion = 500 ml what is the value for 1 cm of movement?

• 500 ml = 1cm

4 cm ?

Calibration

• (500/4) 1= 125 ml

• So, 1cm = 125 ml

• Lab exercises:– Several problems– Calibration of Aerophone for flow &

Nasometer for nasalence

Oscilloscope

• Makes electrical waveforms and voltages visible on screen

• It allows us to see speech waveforms: Airflow, Pressure, EGG

• Can be computerized or separate module for calibration, etc.

Reading Oscillograms

• Utilize oscillograms of the acoustic signal to visualize amplitude and time based data– Mean vocal period

– Fundamental frequency

– Peak-to-Peak amplitude

– Segment speech into phones based on their acoustic features

Reading OscillogramsComfortable Pitch /a/

t (sec)= .0083 Fo (Hz)= 120Amp (volts)= 25

6 cycles in 50 ms50/6= 8.33 ms or .0083 secF0 (Hz)= 1/t (sec)1/.0083= 120 Hz

Reading Oscillograms

Reading Oscillograms