摘要 |
The output of a noise canceling first or second order electret gradient microphone in a very high noise environment has background noise attenuated and certain phonemes shaped to improve intelligibility by means of a slow action automatic gain control circuit 22 which matches dynamic range of the microphone 10 with dynamic range of the following communication channel, and a fast action automatic gain control circuit 24 in parallel with the first circuit, that reshapes puff noise into plosive, fricative and affricative speech component signals that produced the puff noise. |