Active reduction of harmonic noise from multiple noise sources

摘要

A system and method for reducing harmonic noise caused by two or more noise sources by causing one or more loudspeakers to produce sounds that are at about the same frequencies as the noise and of substantially opposite phase. There is a noise canceller associated with each noise source. Each noise canceller includes a harmonic sine wave generator that generates an output sine wave. Each noise canceller also has an adaptive filter that uses a sine wave to create a noise reduction signal that is used to drive one or more transducers with their outputs directed to reduce noise caused by the noise sources. There is an overlap detector that compares the harmonic frequencies and, based on their proximity, alters the operation of one or more adaptive filters.

主权项

1. A system for reducing harmonic noise caused by a plurality of noise sources by causing one or more loudspeakers to produce sounds that are at about the same frequencies as the noise and of substantially opposite phase, the system comprising:
a plurality of noise cancellers, each noise canceller comprising a harmonic sine wave generator that generates an output sine wave having a frequency that corresponds to the noise to be reduced, and an adaptive filter that uses a sine wave to create a noise reduction signal that is used to drive one or more transducers with their outputs directed to reduce noise caused by the noise sources; and an overlap detector that compares the frequencies of the noise caused by the plurality of noise sources, and, based on the proximity of the frequencies, alters the operation of one or more of the adaptive filters.