| 摘要 |
PCT No. PCT/AU84/00223 Sec. 371 Date Jun. 17, 1985 Sec. 102(e) Date Jun. 17, 1985 PCT Filed Oct. 25, 1984 PCT Pub. No. WO85/02085 PCT Pub. Date May 9, 1985.An amplification circuit for hearing aids performs independent amplification of different frequency bands of the signal generated by a microphone of the hearing aid, to match the loss of hearing of a user of the hearing aid. Prior to this multi-band amplification, however, the microphone output signal is passed through an optional filter having a characteristic which is the inverse of the spectrum of long term speech, and through a signal compressor. The signals from the multi-band amplification are combined using an adder and the combined signal is modified by a control signal derived from the envelope of the signal generated by the microphone. The result of this processing is to cause the range of spectral shapes present in received signals to be enlarged or exaggerated in the output signal, but to cause the range of overall levels present in the received signal to be decreased in the output signal. The processing thus increases both signal comfort and signal discriminability for the hearing impaired user of the hearing aid.
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