US 11,677,879 B2
Howl detection in conference systems
Kai Li, Beijing (CN); David Gunawan, Sydney (AU); Feng Deng, Beijing (CN); and Qianqian Fang, Beijing (CN)
Assigned to DOLBY LABORATORIES LICENSING CORPORATION, San Francisco, CA (US)
Filed by DOLBY LABORATORIES LICENSING CORPORATION, San Francisco, CA (US)
Filed on Mar. 10, 2022, as Appl. No. 17/691,966.
Application 17/691,966 is a continuation of application No. 16/640,169, granted, now 11,277,518, previously published as PCT/US2018/053119, filed on Sep. 27, 2018.
Claims priority of provisional application 62/575,701, filed on Oct. 23, 2017.
Claims priority of application No. PCT/CN2017/104604 (WO), filed on Sep. 29, 2017; and application No. 17201011 (EP), filed on Nov. 10, 2017.
Prior Publication US 2022/0201125 A1, Jun. 23, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04M 3/56 (2006.01); G10L 25/48 (2013.01)
CPC H04M 3/568 (2013.01) [G10L 25/48 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method of howl detection, comprising:
detecting, during a communication session between two or more communication devices at two or more locations, a howl state, the howl state being a state of acoustic feedback involving the two or more communication devices in a teleconference client location, wherein detecting the howl state includes:
receiving audio data from one or more of the communication devices;
transforming the audio data from time domain to frequency domain;
dividing the transformed audio data in frequency bands;
detecting, in the transformed and banded audio data, at least one of short-term spectral features or medium-term spectral and temporal features, the short-term spectral features and medium-term spectral and temporal features being structural features of a howl, wherein short-term is in the order of tens of milliseconds and medium-term is in the order of hundreds of milliseconds;
estimating a howl presence probability and outputting a howl indicator indicative of a presence of the howl state; and
determining which of the two or more communication devices is causing the howl state.