CPC G10K 11/17854 (2018.01) [G10K 11/17823 (2018.01); G10K 11/17825 (2018.01); G10K 11/17881 (2018.01); H04R 1/406 (2013.01); H04R 3/005 (2013.01); G10K 2210/3026 (2013.01); G10K 2210/3027 (2013.01); G10K 2210/3028 (2013.01)] | 20 Claims |
1. An active sound cancelling device that comprises: a primary external microphone that produces a primary receive signal; a secondary external microphone that produces a secondary receive signal, the primary and secondary receive signals representing ambient audio that includes sound having a predominate direction of arrival; a speaker that converts an output signal into internal audio to at least partly cancel said sound, the output signal including a forward cancellation signal; a forward filter that operates solely on the primary receive signal to produce the forward cancellation signal; and a direction finder that operates on the primary and secondary receive signals to derive an estimate of said predominate direction of arrival, the direction finder adjusting the forward filter to implement a filter response corresponding to said estimate.
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