Effect of hearing aids with directional microphones in different acoustic environments.

In a number of studies, hearing aids with directional microphones and conventional hearing aids with omni-directional microphones were compared. Listening tests with normal-hearing and hearing-impaired persons as well as objective measurements were performed in rooms differing with regard to reverberation and background noise. Furthermore, a number of hearing-impaired persons were interviewed about their experience of the two types of hearing aid. The results show that hearing aids with directional microphones are superior to the conventional aids in a number of situations. The effect of the directional microphone is of particular significance when listening conditions are difficult because of loud background noise. In situations with reverberation and less background noise the difference is less marked. None of the hearing-impaired listeners had observed any particular disadvantages attributable to the lesser sensitivity of directional microphones to sound coming from the rear and to low-frequency sounds.