Comparison of binaural beamformers for speech extraction in complex auditory scenes

Abstract

The goal of this study was to assess and compare the capacities of several array-processing algorithms to extract on-axis signals in the presence of one or more off-axis interferers. Performance comparisons are made between the localization/extraction (L/E) algorithm [Liu et al., J. Acoust. Soc. Am. 108, 1888–1905 (2000)], the frequency-banded minimum-variance beamformer (FBMVB) [Lockwood et al., J. Acoust. Soc. Am. 106, 2278 (1999)], the Frost beamformer, the Griffiths–Jim generalized sidelobe canceller (GSC), and the Peissig–Kollmeier (P-K) algorithm [Kollmeier et al., J. Rehab. Res. Dev. 30, 82–94 (1993)]. The two metrics used to evaluate algorithm performance were the signal-to-noise ratio gain (SNRG) and the intelligibility-weighted signal-to-noise ratio gain (IWSNRG). The signals used simulated an omnidirectional microphone array in free field and were composed of sentence-length speech by male and female speakers against a background of one to four interfering sound sources. Overall, the IWSNRGs for the L/E and FBMVB algorithms were similar to those for the Frost, GSC, and P-K algorithms when there was a single interferer, but 3–4 dB higher when there were two or more interferers. This study shows that FBMVB and L/E algorithms hold promise for hearing aids to be used in noisy environments. [Work supported by NIH-NIDCD Grant R21DC04840.]