US 12,444,431 B1Granted

Microphone reference echo cancellation

AssigneeAmazon Technologies, Inc.

InventorsCarlos Renato Nakagawa, Ludger Solbach, Robert Ayrapetian

Life of this patent

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Abstract

Techniques for improving microphone noise suppression are provided. When a playback signal is available, a device may use the playback signal as a reference while performing Acoustic Echo Cancellation (AEC) processing. When the playback signal is not available, the device may instead use microphone audio signal(s) as the reference while performing Adaptive Interference Cancellation (AIC) processing. For example, the device may use first audio data generated by first microphones as the reference while performing AIC processing on the first audio data and second audio data generated by second microphones. As the adaptive filter used to perform AIC processing is updated at a slower rate, the reference signal only cancels stationary portions of the first audio data (e.g., noise), leaving a representation of transient sounds such as speech. In some examples, the device may perform AIC processing and AEC processing in series.

Claims23

Dependent claims

A computer-implemented method, the method comprising:

receiving first audio data associated with a first microphone;
receiving second audio data associated with a second microphone, the second audio data representing a combination of speech and noise;
generating, by a first adaptive filter using the first audio data as a first target signal and the second audio data as a first reference signal, a first portion of third audio data, wherein generating the first portion of the third audio data further comprises:
generating first reference audio data by applying first filter coefficient values to the second audio data, the first reference audio data representing the noise, and
generating the first portion of the third audio data by subtracting the first reference audio data from a first portion of the first audio data;
generating, by a second adaptive filter using the second audio data as a second target signal and the second audio data as a second reference signal, a first portion of fourth audio data, wherein generating the first portion of the fourth audio data further comprises:
generating second reference audio data by applying second filter coefficient values to the second audio data, the second reference audio data representing the noise, and
generating the first portion of the fourth audio data by subtracting the second reference audio data from a first portion of the second audio data;
generating, by a beamformer component, a first portion of directional audio data using the first portion of the third audio data and the first portion of the fourth audio data, the directional audio data comprising:
first beamformed audio data corresponding to a first direction relative to a device, and
second beamformed audio data corresponding to a second direction relative to the device, the second direction different from the first direction;
and
causing an action to be performed using the directional audio data.

10 more elements

A system comprising:

at least one processor;
and
memory including instructions operable to be executed by the at least one processor to cause the system to:
receive first audio data associated with a first microphone;
receive second audio data associated with a second microphone, the second audio data representing a combination of speech and noise;
generate, by a first adaptive filter using the first audio data as a first target signal and the second audio data as a first reference signal, a first portion of third audio data, wherein generating the first portion of the third audio data further comprises:
generating first reference audio data by applying first filter coefficient values to the second audio data, the first reference audio data representing the noise, and
generating the first portion of the third audio data by subtracting the first reference audio data from a first portion of the first audio data;
generate, by a second adaptive filter using the second audio data as a second target signal and the second audio data as a second reference signal, a first portion of fourth audio data, wherein generating the first portion of the fourth audio data further comprises:
generating second reference audio data by applying second filter coefficient values to the second audio data, the second reference audio data representing the noise, and
generating the first portion of the fourth audio data by subtracting the second reference audio data from a first portion of the second audio data;
generate, by a beamformer component, a first portion of directional audio data using the first portion of the third audio data and the first portion of the fourth audio data, the directional audio data comprising:
first beamformed audio data corresponding to a first direction relative to a device, and
second beamformed audio data corresponding to a second direction relative to the device, the second direction different from the first direction;
and
cause an action to be performed using the directional audio data.

13 more elements

A computer-implemented method, the method comprising:

sending playback audio data to one or more loudspeakers;
receiving first audio data associated with a first microphone;
receiving second audio data associated with a second microphone;
generating, by a first adaptive filter using the first audio data as a first target signal and both the second audio data and the playback audio data as first reference signals, a first portion of third audio data, wherein generating the first portion of the third audio data further comprises:
generating first reference audio data by applying first filter coefficient values to the second audio data and the playback audio data, and
generating the first portion of the third audio data by subtracting the first reference audio data from a first portion of the first audio data;
generating, by a second adaptive filter using the second audio data as a second target signal and both the second audio data and the playback audio data as second reference signals, a first portion of fourth audio data, wherein generating the first portion of the fourth audio data further comprises:
generating second reference audio data by applying second filter coefficient values to the second audio data and the playback audio data, and
generating the first portion of the fourth audio data by subtracting the second reference audio data from a first portion of the second audio data;
generating a first portion of output audio data using the first portion of the third audio data and the first portion of the fourth audio data;
and
causing an action to be performed using the output audio data.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/488,471Filed 29 Sep 2021
Granted: 14 Oct 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

G10L 21/0364
By changing the amplitude: for improving intelligibility
G10K 11/17823
Characterised by the analysis of the input signals only: reference signals, e.g. ambient acoustic environment
G10L 21/0208
Speech enhancement, e.g. noise reduction or echo cancellation: noise filtering
H04L 27/2651
Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators: modification of fast Fourier…