Comparison of performance across three directional hearing aids.

This study compared the speech recognition performance of 12 hearing-impaired listeners fit with three commercially available behind-the-ear hearing aids in both directional and omnidirectional modes. One digitally programmable analog and two "true digital" hearing aids were selected as test instruments. Testing was completed in both "living room" and anechoic room environments. Speech recognition was examined using modified forms of the Hearing in Noise Test and the Nonsense Syllable Test. The single competing stimuli of these tests were replaced with five uncorrelated competing sources. Results revealed a significant speech recognition in noise advantage for all directional hearing aids in comparison to their omnidirectional counterparts. Maximum performance of the directional hearing aids did not significantly vary across circuit type, suggesting that processing differences did not affect maximum directional hearing aid performance. In addition, the results suggest that performance in one reverberant environment cannot be used to accurately predict performance in an environment with differing reverberation.