Patent ID: 9373318
Filing Date: 2016-06-21
CPC Classification: G10K,G10L,H04R

Claim Text:
1. A method, comprising: producing output audio at a speaker of a first device; generating reference clock cycles at the first device to establish a first signal rate; generating a digital reference signal that contains the output audio at the first signal rate; maintaining a reference index at the first device, the reference index having a value that is incremented in response to the reference clock cycles; providing the digital reference signal to a second device; repeatedly providing a current value of the reference index to the second device; generating input clock cycles at the second device to establish a second signal rate; generating a digital audio signal from a microphone of the second device at the second signal rate, wherein the digital audio signal contains the output audio produced by the first device; maintaining an input index at the second device, the input index having a value that is incremented in response to the input clock cycles; determining a rate of change of the reference index and a rate of change of the input index based at least in part on the repeatedly provided current value of the reference index and a corresponding current value of the input index; comparing the rate of change of the reference index and the rate of change of the input index to determine a signal rate difference between the first and second signal rates; increasing or decreasing at least one of the second signal rate of the digital audio signal or the first signal rate of the digital reference signal to reduce the signal rate difference; and performing acoustic echo cancellation at the second device in response to the digital reference signal to suppress the output audio in the digital audio signal.