how to make good audio recordings in the field?

How to make good audio

recordings in the field?

held January 2006 at the LSA meeting in Albuquerque, New Mexico

Sven GrawunderMax Planck Institute for evolutionary Anthropology,

Dep. of Linguistics, Leipzig, Germany

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How to decide on what I need? What is good?Everybody will tell you: “It depends on… What do you want to do? What for? What is the field (recording) situation like? What can You handle? How big is your budget?

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Technology

Purpose

Quality

Field situation

Feasibility

Costs

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Costs (technique,

transport)

Feasibility(Power supply,

Know How)

Purpose(documentation,

specific elicitation)

Recording Quality (frequency range,

S/N ratio, quantization )

Technology (Microphone,

Recorder)

Field situation (recording

environment, speaker)

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Goals (purpose) Recorders Microphones (incl. wind shield) Setups Field situation (recording environment)

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Analysis Transcription Annotation

Human hearing (20-18000Hz)

Pitch Intensity Formant estimation VOT Voice Quality

Common practice in acoustic phonetic analysis (40-12000Hz)

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Why field recordings? language

documentation (variety of linguistic genres, incl. musical genres)

conversational analyses

oral history

specific elecitation of paradigms for a decent number of speakers (morphosyntax, phonology, phonetics) Wordlists Narrative interview Short stories

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Example 1

Time (s)34.0026 48.0155

-0.7548

0.8599

0

Time (s)34.0026 48.0155

0

5000

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Field situation Ambient noises (people, animals, natural

sources, vehicles, machines etc.) Climate (temperature range, humidity) Long Distances (Transport) Energy supply Interacting in foreign languages (working

language, contact language, elicited language)

Equipment

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Recorders Analog/Digital (costs, formats, media) Digital Formats (16bit PCM, 22.05kHz,

44.1kHz, 48kHz) Quality (signal-to-noise ratio) Power Supply (accumulator / battery) Metering (details, delay, channel split) Media (costs, durability, long-lasting)

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Barely acceptable to acceptable

Acceptable (but not recommendable)

IPod PC/Mac Laptop

internal soundcard dv-camera tone (ext.

mic)

Barely acceptable (but not recommendable)

Micro cassettes via Dictaphone

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Good to Very Good Good (but not

recommendable) Tape recorders

(analogue, DCC)

(Hi-)MD recorders

Very good DAT-Recorder Solid State Recorder

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DAT-Recorders

Sony TCD-D100

TASCAM DA-P1

Fostex PD 4 MK II

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solid state recorders

But: •Power supply via Accu•Price

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A good solution for the field? e.g. Marantz PMD 660

Battery powered Individual Channel

metering Mono recording possible 44.1 & 48 kHz / 16bit Speakers + Line Out Professional XLR Input

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Not bad, but …

It needs E-net connection for direct USB-copying to PC/MAC card reader

Bad circuit insulation: phantom power current influences the recording Never run out of batteries shielded cables, self powered mics

Actual presets are invisible

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smaller siblings

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Saving Raw DataTo your computer Via Card-Reader orDirectly via USB-cable (Electricity needed!!!)

Another solution:Direct Copying to a “mobile photo hard drive”

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MD and Hi-MD ATRAC opaque format ATRACWAV : Don’t betray yourself MD-WAVMD-PC: Beware losing your

data Still Open Software “needed”

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Microphones Frequency range Frequency response directionality powering

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Microphone types built-in mics only in case of emergency!!!

bad quality machine noise omni directional

Dynamic mics mic-mouth distance crucial

Self-powered electrets (condenser) mics Rather than phantom powered condenser mics

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Frequency responseFrequency range

Directionality

•Omnidirectional (cartoid charcteristic)•Directional (hyperbolic characteristic)

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Microphone stands On a tripod or stand? On the table? In your hand? On the speaker? Head mounted mic?

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21 / 02 / 06

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Mono or Stereo???Mono Elicitation (One-to-

one) 1 Speaker (+ close

standing interviewer)

Stereo More than 1 Speaker Moving Speakers Music

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AKG C100 S

Sony ECM-MS957

StereoMono

Shure Beta 53 B

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windshields

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Don’t ignore… Phantom power (48 Hz) Electric circuit (55-60 Hz) Cable (kinks and adapters) Cable shielding (microphone cable, NOT

monitor cable) Connections (jacks, plugs etc.)

Field conditions

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The 7 enemies of your equipment Dust Heat Humidity / Water Cold Hard shaking/sudden

motion/vibration Thieves

Yourself

Insolate your devices! Watch the cables! Keep the equipment

dry!

Protect your devices!!! Watch or let watch! Take save backups

with you!!!

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Some Rules 1 (Time) Have a time buffer Expect that the

recording (setup) takes twice as long as in the lab

Practice the record setup (microphone settings, cable ports/jacks, recorder settings)

Check “Recording Onset Time” (especially for Tape-Recorders of all types: MC, DAT, DCC)

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Some Rules 2 (Equipment) Get to know your equipment before you go

to the field You don’t want to play with settings in a real

situation Consider that the field session may be a

‘stressful’ situation You need to focus on your subject (plus

Monitoring, Metering, Prompting paradigms, Making notes, …)

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Some Rules 3 (Supply) Make sure that you never run out of Power

(Batteries)! Accumulators Solar panel for recharging?

Make sure that you never run out of storage (Cassetes, Cards, etc.)! Consider a ratio of 5:1

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Some Rules 4 (Field Situation) Get aware of the recording environment

The more “natural” the more “distorted” – Lower sometimes your expectations

Nonetheless try to control the recording environment

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Recording environment Choose a possibly quiet location Close doors and windows Cover large reverberant surfaces Ask for turning off lights, refrigerators, fans,

air conditioning etc. Remove anything that ticks, buzzes, bangs,

rattles, squeaks, hisses, or otherwise makes itself heard

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Speaker Find the appropriate Microphone – Mouth

distance (Headworn M. / Static M.) Watch hands and feet Ask for reiterations

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Some Rules 5 (After Recording) Control your data again – listen through

your recordings Make notes (on settings, solutions, etc.) Don’t lower the quality requirements for

digitization

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References: EMELD: http://emeld.org/school/toolroom/ DOBES: http://www.mpi.nl/DOBES Oral history:

http://www.historicalvoices.org/oralhistory/ http://bartus.org/akustyk/

signal_aquisition.pdf Radio feature literature

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Good luck with your recordings!!!