US 11,695,876 B2
Echo detection
Alexandre Loiko, Mountain View, CA (US); Marcus Wirebrand, Huddinge (SE); Samuel Martin Zackrisson, Mountain View, CA (US); Ivo Creusen, Stockholm (CA); Mans Gustaf Sebastian Ullberg, Mountain View, CA (US); Alessio Bazzica, Järfälla (SE); and Daniel Johansson, Mountain View, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Filed by Google LLC, Mountain View, CA (US)
Filed on Oct. 5, 2021, as Appl. No. 17/450,014.
Application 17/450,014 is a continuation of application No. 17/260,219, granted, now 11,418,655, previously published as PCT/US2019/042208, filed on Jul. 17, 2019.
Claims priority of provisional application 62/700,138, filed on Jul. 18, 2018.
Prior Publication US 2022/0030116 A1, Jan. 27, 2022
Int. Cl. H04M 9/08 (2006.01); G10L 21/0208 (2013.01)
CPC H04M 9/082 (2013.01) [G10L 21/0208 (2013.01); G10L 2021/02082 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented echo detection method when executed by data processing hardware causes the data processing hardware to perform operations comprising:
receiving a frequency representation of a playout audio signal corresponding to a microphone audio signal;
determining features based on the frequency representation of the playout audio signal, each feature corresponding to a pair of frequencies of the frequency representation of the playout audio signal and a period of time between the pair of frequencies, each corresponding pair of frequencies comprising a respective first frequency and a respective second frequency, the respective first frequency different than the respective second frequency;
determining that a match occurs between a first feature based on a frequency representation of the microphone audio signal and a second feature based on the frequency representation of the playout audio signal; and
determining that an echo within the microphone audio signal exists when a delay value between the first feature and the second feature satisfies an echo value threshold that is predictive of a respective echo being human perceptible.