Microphone position and gain calibration for a large-aperture microphone array

Large-aperture microphone arrays have the potential for providing quality speech acquisition from multiple talkers over a large focal area for such applications as teleconferencing and speech-recognition input. The cost of computing is rapidly approaching the point at which these arrays will be prac...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on speech and audio processing 2005-01, Vol.13 (1), p.42-52
Main Authors: Sachar, J.M., Silverman, H.F., Patterson, W.R.
Format: Article
Language:English
Subjects:
Acoustic measurements
Acoustics
Applied sciences
array processing
Arrays
Calibration
Channels
Costs
Electrets
Exact sciences and technology
Gain
Gain measurement
Information, signal and communications theory
locations
Microphone arrays
microphone positions
Microphones
Noise levels
Position measurement
Signal processing
Speech
Speech processing
Telecommunications and information theory
Teleconferencing
Time measurement
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Large-aperture microphone arrays have the potential for providing quality speech acquisition from multiple talkers over a large focal area for such applications as teleconferencing and speech-recognition input. The cost of computing is rapidly approaching the point at which these arrays will be practical in many common environments. However, an important issue is the calibration of an array. We discuss procedures to accurately determine both the coordinates in three-dimensions for the position of each microphone and the individual gains of each microphone/microphone channel. For the positions, we found that calibration by direct measurement, using a surveyor's transit, is simply too error prone, time consuming, and difficult for large arrays and is too inaccurate for small arrays. We have also seen that without the careful matching of inexpensive electret microphones, the channel sensitivities vary by as much as 6 dB and performance can be enhanced by suitable compensation. This paper describes new apparatus and techniques for automatic calibration using acoustic signals. Experimental results using both small and large-aperture microphone array systems show the acoustically-determined positions to be more consistent than the ones measured directly. Gain measurements are somewhat more difficult but gains can be found within 1-2 dB with reasonable care.
ISSN:1063-6676
2329-9290
1558-2353
2329-9304
DOI:10.1109/TSA.2004.834459