Effect of two-microphone noise reduction on speech recognition by normal-hearing listeners.

An idealized 2-channel noise reducing adaptive filter of the type developed by Widrow requires that one channel contain noise only and that the microphones be fixed in position relative to the signal and noise sources. These conditions are unlikely to be met in a wearable hearing aid. In a typical situation, the microphones will be mounted in close proximity on a moving head in a room that is moderately reverberant. Experimental data have been obtained showing that, despite these deviations from the ideal conditions, significant improvements in speech intelligibility can be obtained using 2-channel adaptive filtering.