Dual feedback control system for implantable hearing instrument

A method for reducing noise in a drive signal of an implantable hearing instrument, comprising:

• producing a first cancellation signal associated with motion of an implanted microphone;
• producing a second cancellation signal indicative of feedback received by said implanted microphone from operation of an implanted auditory stimulation device,
• combining said first and second cancellation signals to an output signal of said implanted microphone to generate a first and second cancelled microphone output signals, respectively;
• selecting at least a portion of one of said first and second cancelled microphone signals for at least one frequency band;
• and
• utilizing at least said portion of selected signal to generate a digital drive signal for use in actuating an implantable auditory stimulation device.

A system for reducing noise in a drive signal of an implantable hearing instrument wherein an implantable processor receives an input signal originating from an implantable microphone and generates said drive signal for actuating an implantable auditory stimulation device, comprising:

• a microphone operative to receive sound and generate a microphone output, said microphone being adapted for subcutaneous positioning;
• a motion sensor for generating a motion signal indicative of motion of said microphone;
• a first digital filter adapted to receive said motion signal and generate a filtered motion signal that models a response of said microphone to motion;
• a first summation device for combining said microphone output and said filtered motion signal to generate a first compensated microphone signal;
• a second digital filter adapted to receive said drive signal and generate a feedback signal that models a response of said microphone to operation of said implantable auditory stimulation device;
• a second summation device for combining said microphone output and said feedback signal to generate a second compensated microphone signal;
• and
• a controller operative to select at least a portion of one of said first and second compensated microphone signals for at least one frequency band and provide such selected portions to a signal processor for use in generating drive signals for actuating said implantable auditory stimulation device.