Sound-dependent ANR signal processing adjustment

摘要

A method of controlling provision of active noise reduction (ANR) by an ANR circuit of a personal ANR device comprising: monitoring amplitude levels of sounds of more than one frequency that are within a piece of audio employed by the ANR circuit in providing the ANR; starting compression of an ANR reference noise sound from which an ANR anti-noise sound is derived in response to a first sound within the piece of audio having a first frequency and having an amplitude that reaches a first predetermined level; and starting compression of the ANR reference noise sound in response to a second sound within the piece of audio having a second frequency different from the first frequency and having an amplitude that reaches a second predetermined level greater than the first predetermined level.