Convention Paper
Amplitude Compression in Hearing Aids
AES Convention 46 · Paper 945 · September 1973
Abstract
Amplitude compression is used in hearing aids (HAs) for protection and dynamic range reduction. While small distortion of strong signals should be secured, deformations of the output voltage may be observed. Intelligibility tests were preformed with commercially available HAs with amplitude compression (HACs) with various values of time constants of compression, harmonic distortion, and distortion during overshoots. Ten normal hearing listeners were presented with speech of Modified Rhyme Test (MRT) with signal to noise ratio (s/n) of -2 dB and +2 dB. For the first condition the shorter were the time constants of compression the better was the result. For the second condition the importance of time constants decreased and distortion during overshoots or harmonic distortion gained weight. The larger the distortion the smaller the score.
