The Choice of Compression Speed in Hearing Aids: Theoretical and Practical Considerations and the Role of Individual Differences

Compression is used in hearing aids to compensate for the effects of loudness recruitment. This article describes the distinction between, and relative merits of, slow and fast compression systems. A study of Gatehouse and coworkers leads to the following conclusions: (a) The benefit from compression is greatest among individuals who experience a wide range of sound levels within short periods of time, (b) slow compression generally leads to higher listening comfort than fast compression, (c) the benefit from fast compression varies across individuals, and those with high cognitive ability are able to benefit from fast compression to take advantage of temporal dips in a background sound. It is argued that listening in the dips depends on the ability to process the temporal fine structure of sounds. It is proposed that a test of the ability to process temporal fine structure might be useful for selecting compression speed for an individual.