The amplification of a hearing aid should be provided in a way which makes the amplified sound audible without being uncomfortably loud. If the sound is too loud at a certain frequency, the user may turn down the volume control to a point where the gain at other frequencies is insufficient.
The highest sound level, a certain hearing aid can produce, is specified as the maximum output level of that aid. If this level is too loud for the user, it must be reduced. The output control and the compression control are used to accomplish this task.
The Output Control
The best way to reduce the output of a hearing aid will depend very much on the properties of its output control and AGC circuit. Normally, the output control; when ...