FEEDFORWARD-BASED ANR ADJUSTMENT RESPONSIVE TO ENVIRONMENTAL NOISE LEVELS

摘要

A compression circuit of a device providing feedforward-based ANR monitors the electric signal output by a feedforward microphone for indications of the voltage levels of the electric signal output by the feedforward microphone ceasing to have a linear relationship with the acoustic levels of the sounds detected by the feedforward microphone. As long as there are no such indications, the compression circuit relays a signal to a feedforward anti-noise generator that is at least representative of the electric signal output by the feedforward microphone in which the sounds represented are not compressed, perhaps by directly relaying the signal output by the feedforward microphone as feedforward reference sounds. However, in response to detecting such indications, the compression circuit compresses the sounds represented by the signal output by the feedforward microphone prior to providing those sounds to the feedforward anti-noise generator as feedforward reference sounds, perhaps by attenuating the signal output by the feedforward microphone.