System for reducing the effects of acoustically noisy environments on detected sound signals

摘要

The intensity of an incoming sound signal in a pickup device is detected and used to control the signal output by a microphone (20) of the device. In an exemplary configuration, a signal proportional to the microphone output signal is applied to a level detector (26) which senses for example the average amplitude of the signal. The level detector (26) then generates a control signal (fc) representative of the level of the sound detected by the microphone (20). The control signal (fc) is applied to a filter (24) receiving the microphone output signal and operates to dynamically control the frequency of the filter (24) and its effects on the microphone output signal. The filter is thus used to reduce interfering signal frequencies in proportion to intensity of the sensed sound signal.