Open Access

Postfiltering Using Multichannel Spectral Estimation in Multispeaker Environments

  • Hai Quang Dam1,
  • Sven Nordholm1,
  • Hai Huyen Dam1Email author and
  • Siow Yong Low1
EURASIP Journal on Advances in Signal Processing20072008:860360

Received: 14 September 2006

Accepted: 5 July 2007

Published: 16 July 2007


This paper investigates the problem of enhancing a single desired speech source from a mixture of signals in multispeaker environments. A beamformer structure is proposed which combines a fixed beamformer with postfiltering. In the first stage, the fixed multiobjective optimal beamformer is designed to spatially extract the desired source by suppressing all other undesired sources. In the second stage, a multichannel power spectral estimator is proposed and incorporated in the postfilter, thus enabling further suppression capability. The combined scheme exploits both spatial and spectral characteristics of the signals. Two new multichannel spectral estimation methods are proposed for the postfiltering using, respectively, inner product and joint diagonalization. Evaluations using recordings from a real-room environment show that the proposed beamformer offers a good interference suppression level whilst maintaining a low-distortion level of the desired source.

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Authors’ Affiliations

Western Australian Telecommunications Research Institute (WATRI)


© Hai Quang Dam et al. 2008

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.