Patent ID: 7203328

Claim:
An amplifier circuit for a hearing aid, comprising: an amplification device having an input at which acoustically-generated signals and inductively-generated signals are present; a first filter device operating with first filter coefficients connected in a first feedback path to said amplification device for compensating acoustic feedback in said first feedback path; a first switch connected to said input for selectively connecting and disconnecting said acoustically-generated signals to and from said input a second filter device, different from said first filter device and operating with second filter coefficients, connected in a second feedback path to said amplification device for statically compensating inductive feedback in said second feedback path; and a second switch connected between said input and said second filter device for connecting and disconnecting said second filter device to and from said input, said first switch being operable to disconnect said input from said acoustically-generated input signal while said second switch is operated to interrupt said second feedback oath for calibration of said second filter device.