HEARING AID WITH PERMANENTLY ADJUSTED FREQUENCY RESPONSE

摘要

A hearing aid is permanently adjusted to match prescribed amplification characteristics at predetermined frequencies. A single channel filter (24) includes three identical filter stages (60, 62, and 64) that are optionally cascaded in series. Each of the filter stages (60, 62, and 64) exhibits a frequency response curve having a first corner frequency (36) below which the magnitude of the response curve approaches a predetermined minimum value, a second corner frequency (38) above which the magnitude of the response curve approaches a maximum value, and a predetermined gain in magnitude between the minimum and maximum values.