Robustness of an adaptive beamforming method for hearing aids.
We describe the results of computer simulations of a multimicrophone adaptive-beamforming system as a noise reduction device for hearing aids. Of particular concern was the system's sensitivity to violations of the underlying assumption that the target signal is identical at the microphones. Two- and four-microphone versions of the system were tested in simulated anechoic and modestly-reverberant environments with one and two jammers, and with deviations from the assumed straight-ahead target direction. Also examined were the effects of input target-to-jammer ratio and adaptive-filter length. Generally, although the noise-reduction performance of the system is degraded by target misalignment and modest reverberation, the system still provides positive advantage at input target-to-jammer ratios up to about 0 dB. This is in contrast to the degrading target-cancellation effect that the system can have when the equal-target assumption is violated and the input target-to-jammer ratio is greater than zero.
Peterson
P M
PM
Massachusetts Institute of Technology, Research Laboratory of Electronics, Cambridge.
Wei
S M
SM
Rabinowitz
W M
WM
Zurek
P M
PM
D003198:Computer Simulation; D004867:Equipment Design; D006310:Hearing Aids; D012815:Signal Processing, Computer-Assisted; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013067:Speech Perception