Automatic gain control compresses sound to fit impaired hearing’s reduced dynamic range.

Evidence

Using a limiter alone with linear amplification is inadequate in hearing aids, since hearing loss is often level-dependent because of recruitment. Thus, hearing aids typically employ automatic gain control (AGC) which enables the level compression of sound – the amplification of low input levels more than high ones. Consequently, the dynamic range of the input signal is reduced so that it better fits the decreased dynamic range of the impaired hearing. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2743

Categorization

• DEFINE: Defines AGC and recruitment-driven compression as responses to level-dependent hearing loss.