Active noise control system with a helmholtz resonator

摘要

An active noise control system (26) includes an error microphone (28), a speaker (29) and an active resonator (30) which communicate with an ANC controller (32). The active resonator is a Helmholtz resonator which is coupled to an air introduction body (19). The resonance frequency of the active resonator is varied in response to the ANC controller (32) which provides logic which responds to sensor signals to eliminate low frequency noise such that the ANC system speaker (29) will effectively control and/or spectral shape the remaining noise.