Actively reducing internal noise in motor vehicle - using measuring microphone(s) and loudspeaker(s) to compensate detected noise by propagating sound field of opposite phase to that of disturbing noise

摘要

Sensors (2) are deployed to register the surrounding parameters affecting the physical transmission function between the one or more compensating loudspeakers (6) and the one or more measuring microphones (5) as well as between at least one interference source and the microphone(s). The imitated balanced transmission function is corrected from the physical values of the varied noise propagation as ascertained by the sensors. The sensor signals are correlated with values stored in a memory (10) of a digital processor (11). The latter includes a sinusoidal signal generator (12) coupled to a phase regulator (8) as well as an optimising unit (9). The outputs of the latter are fed to an amplitude regulator (7) and the phase regulator. The input of the optimising unit is connected to the microphone(s). ADVANTAGE - Pertaining transmission function ascertained and taken into account in calculating compensation signal.