Vorrichtung zur aktiven Geräuschdämpfung mit adaptiver Steuerung

摘要

An active noise attenuating device includes a first microphone (22) located in a propagation path (21) of noise, a loud speaker (23) located downstream from the first microphone (22), a second microphone (24) located downstream from the loud speaker (23) for receiving sound, and an operational unit (26) for executing an operation on the basis of a detection signal from the first microphone (22) to generate a control signal supplied to the loud speaker (23) so that a sound interfering with the noise is produced. An operational factor of the operational unit (26) is controlled by an adaptive controller (33) on the basis of the detection signal from the second microphone (24) so that an amount of noise attenuated by the sound produced from the loud speaker (23) is rendered maximum. A transfer characteristic of a transfer path between the loud speaker (23) and the second microphone (24) is identified on the basis of the detection signals generated by the second microphone (24) when a sound represented by a periodical identifying signal is produced in a plurality of periods. An operational factor of the adaptive controller (33) is adjusted by an adaptive control identifying unit (40) on the basis of the identified transfer characteristic. $$