US 11,972,767 B2
Systems and methods for covariance smoothing
David S. McGrath, Rose Bay (AU); Stefanie Brown, Lewisham (AU); and Juan Felix Torres, Darlinghurst (AU)
Assigned to Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
Appl. No. 17/632,225
Filed by Dolby Laboratories Licensing Corporation, San Francisco, CA (US)
PCT Filed Jul. 31, 2020, PCT No. PCT/US2020/044670
§ 371(c)(1), (2) Date Feb. 1, 2022,
PCT Pub. No. WO2021/022235, PCT Pub. Date Feb. 4, 2021.
Claims priority of provisional application 63/057,533, filed on Jul. 28, 2020.
Claims priority of provisional application 62/881,825, filed on Aug. 1, 2019.
Prior Publication US 2022/0277757 A1, Sep. 1, 2022
Int. Cl. G10L 19/008 (2013.01); G10L 19/26 (2013.01); G10L 21/0208 (2013.01); G10L 25/18 (2013.01)
CPC G10L 19/008 (2013.01) [G10L 19/26 (2013.01); G10L 21/0208 (2013.01); G10L 25/18 (2013.01); G10L 2021/02082 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of providing an audio service, the method comprising:
for a time-domain sequence of signal frames, comparing an effective count of bins in a frequency band to a desired count of bins for the frequency band;
computing a forgetting factor for the frequency band as a ratio of the effective count to the desired count;
for each frequency band of a plurality of frequency bands, in response to determining that the effective count of bins in the frequency band is smaller than the desired count, generating a respective smoothed band-specific covariance matrix for a present signal frame using a previously generated value of the respective smoothed band-specific covariance matrix for a previous signal frame relative to the present signal frame and the forgetting factor; and
generating an audio signal for the audio service using frequency domain representations of the time-domain sequence of signal frames and further using corresponding sets of the respective smoothed band-specific covariance matrices,
wherein the comparing, computing, and generating are performed by a system including one or more computer processors.