### ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

## 2pSP2. Stable dereverberation using microphone arrays for speaker
verification.

**A. C. Surendran
**

**
J. L. Flanagan
**

**
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*Ctr. for Comput. Aids for Indust. Productivity, P.O. Box 1390, Piscataway,
NJ 08855-1390
*

*
*
The impulse response of a reverberant environment, in general, is a
nonminimum phase and cannot be inverted. But an exact inverse of the
environment can be obtained by modeling the room as a multiple input--output
(MINT) system [M. Miyoshi and Y. Kaneda ICASSP (1986)]. In this report, this
model is applied to a microphone array and is used as a front-end processor for
a speaker verification system. The G matrix is inverted using row action
projection (RAP), an iterative approach to solving a system of linear
equations. Starting from an initial guess, the solution is repeatedly projected
onto each hyperplane of the equation system until it converges. The method is
stable, robust to noise, and converges to the pseudo-inverse solution. In
computer-simulated experiments, the signal-to-reverberant-noise ratio is found
to improve with the number of microphones in the array. A speaker verification
system using the array is evaluated at various signal-to-competing-noise ratios
(SCNR). Results suggest that verification performance can be substantially
elevated in adverse acoustic environments.