peak clipping (hearing aid) (PC)
Peak clipping( PC) is a limiting technique used in hearing aids in which the maximum output pressure( MPO) of the hearing aid is limited to a saturation level, thereby protecting the wearer of the hearing aid from excessive sound pressure and strong sound pressure fluctuations and preventing damage to the ear.
Peak clipping, or peak limitation, limits the amplitude of volume peaks so that the volume level, or sound pressure, does not exceed a predetermined limit. Level limiting is done with linear or non-linear passive components; with resistors, diodes - silicon and germanium diodes - and Zener diodes. The linear devices degrade the signal-to- noise ratio( SNR) and reduce the dynamic range of the volume, while the nonlinear ones additionally generate intermodulation distortion and degrade the audio quality.
To avoid peak clipping, the gain of the hearing aid can be reduced using Automatic Gain Control( AGC), the hearing aid can use High Level Compressor( HLC), limiters or audio compression.