Noise reduction system for motor vehicle includes transducer adjacent to each exhaust producing compensating noise

摘要

The active device for an engine (10) exhaust system (12) comprises two exhaust outlets (16A, 16B). For each exhaust outlet there is a particular transducer (24A, 24B) for emitting a noise reduction sound wave. A processing line (28) is provided for generating the noise reduction signal, activating the transducers on the basis of this signal. The single processing line is capable of processing an element of signal which is common to both of the exhaust outlets. At each exhaust outlet there is a residual noise sensor (26A, 26B) whose output is fed to the processing line. A single amplifier (38) is provided in the signal processing line. A multiplex system may enable different signals to be processed for the two exhaust outlets.