US 12,444,428 B2
Method and device for variable pitch echo cancellation
Clément Gaultier, Chatillon (FR); Alexandre Guerin, Chatillon (FR); Marc Emerit, Chatillon (FR); and Grégory Pallone, Chatillon (FR)
Assigned to Orange, Issy-les-Moulineaux (FR)
Appl. No. 18/249,225
Filed by Orange, Issy-les-Moulineaux (FR)
PCT Filed Sep. 27, 2021, PCT No. PCT/FR2021/051659
§ 371(c)(1), (2) Date Apr. 14, 2023,
PCT Pub. No. WO2022/079365, PCT Pub. Date Apr. 21, 2022.
Claims priority of application No. 2010570 (FR), filed on Oct. 15, 2020.
Prior Publication US 2023/0395090 A1, Dec. 7, 2023
Int. Cl. G10L 21/0224 (2013.01); G10L 21/0232 (2013.01); G10L 21/0264 (2013.01); G10L 21/0208 (2013.01)
CPC G10L 21/0224 (2013.01) [G10L 21/0232 (2013.01); G10L 21/0264 (2013.01); G10L 2021/02082 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of processing a signal y(t) coming from at least one microphone of an equipment item, the equipment item further comprising at least one loudspeaker intended to be supplied a signal x(t),
the processing of the signal y(t) from the microphone comprising:
at least partially limiting an echo effect induced by the microphone capturing a sound emitted by the loudspeaker in an environment of the equipment item, the sound emitted by the loudspeaker and any possible acoustic reflections following an acoustic path w from the loudspeaker to the microphone,
and comprising, in order to limit the echo effect, a determination ŝ(t) of a useful signal s(t) by subtracting from the signal y(t) coming from the microphone an estimate of an echo signal x(t)*ŵ(t) given by applying a filter ŵ(t) to the signal x(t) supplied to the loudspeaker, the filter ŵ(t) being adaptive by variable step size in order to take account of a change over time of the acoustic path w(t),
the method wherein:
the signal x(t) supplied to the loudspeaker is obtained in the form of a succession over time of frames of signal samples, and
the adaptive filter ŵ(t) is produced at each frame k of samples as a function of an update ΔW(k) to the acoustic path w(t) for this frame k and by applying a normalization Λ satisfying a criterion chosen for minimal variance,
the normalization Λ being a function of a parameter representative of a statistical expectation of the useful signal s(t).