Active noise reduction system for vehicle passenger - uses weighing of microphone signals to simulate virtual source at position of passengers head

摘要

The active noise reduction system uses microphones (1,2) for detecting the noise level at points within the vehicle which are spaced from the passenger's head. The microphones (1,2) are coupled to variable amplifiers (3,4,8,11) supplying weighted output signals to a microprocessor (9) used to generate a similar frequency counter phase noise signal for reducing the effective noise level at the position of the passenger's head. The weighting provided by the variable amplifiers (3,4,8,11) allows the received microphone signals to be adjusted to simulate a virtual microphone source at the position of the passenger's head. ADVANTAGE - Accurate reduction of noise level at position of passenger's head.