Journal of Rehabil itation Research & Development Directional hearing aids: Then and now

Abstract—Directional microphone hearing aids can lead to improved speech recognition when speech and noise are com-ing from different directions. This technology provides limited benefits, however, and in specific instances use of a directional hearing aid mode can be detrimental. This article discusses the benefits and limitations of directional amplification, summa-rizes some current work in directional amplification, and rec-ommends clinical application relative to the use of directional amplification. Key words: critical distance, directional hearing aids, directivity, front-to-back ratio, listening environment, localization, noise reduction, speaker-to-listener distance, speech transmission index