Efficacy of directional-microphone hearing aids

Difficulty understanding speech in the presence of noise is a common cause of users’ dissatisfaction with hearing aids. Several technological approaches have been explored to offer hearing-impaired people better listening ability in noisy environments. Work on microphone directionality has pursued this goal.

According to AETMIS’s evaluation, the few studies presenting an intermediate level of evidence allow us to classify as “experimental” technologies both single-microphone solutions and approaches based on a microphone array. These solutions appear promising but further controlled trials will be required
to confirm their efficacy.

Dual-microphone approaches can be considered “accepted” technologies but only in optimal listening conditions, when the speaker and the noise are diametrically opposite each other in environments with low reverberation. The application of this technology in other conditions reduces (sometimes significantly) their effectiveness. Finally, eligibility requirements for devices with the directionality option must take into account the candidate’s physical and cognitive abilities to use the directional properties effectively.