Robustness of beamforming algorithms with head-related transfer functions

• Published in: The Journal of the Acoustical Society of America 2001-05, Vol.109 (5_Supplement), p.2493-2493
• Main Authors: Lockwood, Michael E., Jones, Douglas L., Bilger, Robert C., Lansing, Charissa R., O’Brien, William D., Wheeler, Bruce C., Feng, Albert S.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4744873

This study examines the robustness of the frequency-banded minimum-variance beamformer (FBMVB) when processing signals from in-the-ear microphones or signals that include head-related transfer function (HRTF) effects. In previous work using simulated signals from a free-field array [Lockwood et al., J. Acoust. Soc. Am. 106, 2278 (1999)], the two-channel FBMVB proved to be highly effective in extracting the signal of a target sound from a known direction amidst multiple interfering sound sources from other unknown directions. When the signals were modified to include the effects of a measured HRTF [G. Gardner and K. D. Martin, J. Acoust. Soc. Am. 97, 3907–3908 (1995)], the performance of the FBMVB improved as measured by the SNR gain and intelligibility-weighted SNR gain. The FBMVB also outperformed conventional algorithms in both the free-field and HRTF tests. Additionally, analytical results show that under certain conditions the FBMVB may extract a target source and perfectly cancel multiple interfering sound sources despite differences in the frequency-dependent intersensor gains for each source. Consequently, the FBMVB may extract signals from the on-axis direction without knowledge of the HRTF, as long as the HRTF in the on-axis direction is identical for both ears. [Work supported by NIH-NIDCD Grant R21DC04840.]