Ultra low current amplifier
Loudness contour compensated hearing aid having ganged volume, bandpass filter, and compressor control
Hearing aid with adjustable frequency response
Hearing aid amplifier
Programmable signal processing device
Microphone with stepped response
Digital hearing aid and method
Prosthetic device for optimizing speech understanding through adjustable frequency spectrum responses
ApplicationNo. 318039 filed on 03/02/1989
US Classes:381/320, Spectral control330/279, And significant control voltage developing means381/120, WITH AMPLIFIER381/323Power supply or programming interface terminals
ExaminersPrimary: Isen, Forester W.
Assistant: McGeary, III, M. Nelson
Attorney, Agent or Firm
International ClassH04R 025/00
AbstractA power efficient hearing aid uses a programmable biasing technique to set the quiescent operating points of amplifiers used by the hearing aid to avoid excessive power usage by the hearing aid. The hearing aid also includes power supply circuitry which develops +1.25 volts and -1.25 volts relative to ground from a single +1.25 volt source. The hearing aid also conserves power by selectively disabling low frequency signal processing channels in the presence of relatively large amplitude ambient noise.