Broadband beamforming with adaptive postfiltering for speech acquisition in noisy environments

In this paper the implementation of a broadband beamformer which is built up by several harmonically nested subarrays for each octave band combined with optimal postfiltering is described. This method has the advantage of providing large sensor distances for the postfilter estimation by simultaneously controlling the directivity of the array. The selection of an optimal postfilter is discussed in detail and its estimation based on a Nuttall/Carter method for spectrum estimation is described. The resulting noise reduction system yields improved performance in diffuse noise fields and no distortions in the case of coherent direct path noise. Furthermore, the system is robust to steering misadjustment.

[1]  R. Zelinski,et al.  A microphone array with adaptive post-filtering for noise reduction in reverberant rooms , 1988, ICASSP-88., International Conference on Acoustics, Speech, and Signal Processing.

[2]  A.H. Nuttall,et al.  Spectral estimation using combined time and lag weighting , 1982, Proceedings of the IEEE.

[3]  Y. Mahieux,et al.  A microphone array for multimedia applications , 1993, Proceedings of IEEE Workshop on Applications of Signal Processing to Audio and Acoustics.

[4]  Norbert Wiener,et al.  Extrapolation, Interpolation, and Smoothing of Stationary Time Series , 1964 .

[5]  F. Jacobsen,et al.  Spatial correlation and coherence in a reverberant sound field , 1987 .

[6]  James L. Flanagan,et al.  Autodirective Microphone Systems , 1991 .

[7]  A. Wasiljeff,et al.  Adaptive Microphone Arrays for Noise Suppression in the Frequency Domain , 1992 .

[8]  Yannick Mahieux,et al.  Performance of adaptive dereverberation techniques using directivity controlled arrays , 1996, 1996 8th European Signal Processing Conference (EUSIPCO 1996).

[9]  Sven Fischer,et al.  Beamforming microphone arrays for speech acquisition in noisy environments , 1996, Speech Commun..

[10]  Jont B. Allen,et al.  Image method for efficiently simulating small‐room acoustics , 1976 .

[11]  John H. L. Hansen,et al.  Discrete-Time Processing of Speech Signals , 1993 .

[12]  Walter Kellermann.  A self-steering digital microphone array , 1991, [Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing.