Patent ID: 8111849

Claim:
A hearing aid comprising: a microphone for converting an environmental sound to an electric signal; a hearing aid processor for hearing aid processing of an output signal of said microphone; an earphone for converting an output signal of said hearing aid processor to a sound signal; an external ear canal microphone for converting a sound within an external ear canal to an electric signal; and a signal processor for comparing an output signal of said external ear canal microphone and the output signal of said hearing aid processor and for automatically adjusting the output signal of said hearing aid processor such that the output signal of said external ear canal microphone approaches the output signal of said hearing aid processor, wherein said signal processor comprises an adaptive filter, the output signal of said hearing aid processor functions as an input signal xk and a desired signal dk of said adaptive filter, and the output signal of said external ear canal microphone functions as a response signal yk of said adaptive filter.