Speech perception in noise using directional microphones in open-canal hearing AIDS

Background: Individuals with impaired hearing find it difficult to understand speech in the presence of background noise - a problem addressed effectively by directional microphones. As open-canal fittings have become increasingly popular in the recent past, so has the debate about the effective directional benefit available from these devices. Purpose: This study investigates the benefit of directional microphones in two commercially available open-canal behind-the-ear hearing aids using the Hearing in Noise Test (HINT). Study Sample: Sixteen individuals, between 50 and 85 year of age, with high-frequency bilateral sensorineural hearing loss and no previous hearing aid experience participated in this study. Data Collection and Analysis: Data Collection and Analysis: Individuals were asked to repeat sentences (presented at 0° azimuth) in the presence of a diffuse-field uncorrelated broadband speech-shaped noise. HINT performance was compared across hearing instruments and conditions using a linear model with repeated measures. Results: There was a directional advantage of 2.6 dB as compared to the unaided condition. Average performance was worse in the omnidirectional mode as compared to the unaided condition. Conclusions: These results suggest that directional signal processing should not be precluded in open-canal instruments for listening in noisy environments.