1. 1 Compression is a method employed to reduce the intensity of either the input to, or output of, a hearing aid in order to achieve maximum auditory comfort of a hearing aid wearer. Input compression reduces the input to a hearing aid, while output compression reduces the output of a hearing aid. Linear hearing aids employ no compression strategies at all.

2. Linear Amplification 70 80 90 100 110 Output (dB SPL) 505560657075808590 Maintains 1:1 input- to-output ratio. Peak Clipping employed to keep output from increasing beyond wearer’s comfort level. Input (dB SPL)

3. Compression 70 80 90 100 110 Output (dB SPL) 505560657075808590 Compression is introduced at a certain point, creating a kneepoint on the input/output curve. Input (dB SPL) Input-to-output ratio is not 1:1 past the kneepoint. The slope of this line depends upon the compression ratio being used.