Patent ID: 9478212
Filing Date: 2016-10-25
CPC Classification: G10K,G10L,H03G,H04R

Claim Text:
1. A personal audio device, comprising: a personal audio device housing; a transducer coupled to the housing for reproducing an output audio signal including an equalized source audio signal for playback to a listener; an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of an acoustic output of the transducer; a processing circuit that implements: a secondary path estimate filter for modeling an electro-acoustical path of a source audio signal through the transducer; a secondary path estimate filter coefficient control block that shapes a response of the secondary path estimate filter in conformity with the error microphone signal; an adjustable equalization filter having a response that generates an equalized source audio signal from the source audio signal to account for effects of changes in the electro-acoustical path of the source audio signal; and an equalizer coefficient control block that adapts the response of the adjustable equalization filter in response to changes in the response of the secondary path estimate filter to shape the response of the adjustable equalization filter in conformity with a response of a target filter by adapting the response of the adjustable equalization filter to minimize a difference between the response of the target filter and the response of the adjustable equalization filter; wherein: