Tone interference cancellation

• US 10,621,981 B2
• Filed: 09/28/2017
• Issued: 04/14/2020
• Est. Priority Date: 09/28/2017
• Status: Active Grant

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Sereshki, Saeed Bagheri
• Primary Examiner(s): Kazeminezhad, Farzad
• Application Number:
  US15/718,521
• Publication Number:
  US 20190096398A1
• Time in Patent Office: 929 Days
• Field of Search: 455570, 348 1401
• CPC Class Codes: G10K 11/1785 Methods, e.g. algorithms; Devices G10K11/1781, G10K11/1783 take precedence
• CPC Class Codes: G10L 15/08 Speech classification or search
• CPC Class Codes: G10L 15/22 Procedures used during a speech recognition process, e.g. man-machine dialogue
• CPC Class Codes: G10L 2015/088 Word spotting
• CPC Class Codes: G10L 2015/223 Execution procedure of a spoken command
• CPC Class Codes: G10L 2021/02085 Periodic noise
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 21/0232 Processing in the frequency domain
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10
• CPC Class Codes: H04M 3/53 Centralised arrangements for recording incoming messages , i.e. mailbox systems
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone

Abstract

Example techniques involve systems with multiple acoustic echo cancellers. An example implementation captures first audio within an acoustic environment and detecting, within the captured first audio content, a wake-word. In response to the wake-word and before playing an acknowledgement tone, the implementation activates (a) a first sound canceller when one or more speakers are playing back audio content or (b) a second sound canceller when the one or more speakers are idle. In response to the wake-word and after activating either (a) the first sound canceller or (b) the second sound canceller, the implementation outputs the acknowledgement tone via the one or more speakers. The implementation captures second audio within the acoustic environment and cancelling the acoustic echo of the acknowledgement tone from the captured second audio using the activated sound canceller.

Claims

1. A system comprising:

one or more speakers;

one or more microphones;

one or more processors;

data storage storing instructions executable by the one or more processors to cause the system to perform operations comprising;

capturing, via the one or more microphones, first audio within an acoustic environment;

determining whether the one or more speakers are (a) playing back audio content or (b) idle;

detecting, within the captured first audio, a wake-word for a voice service;

identifying a set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content;

in response to detecting the wake-word for the voice service and before playing an audible tone in acknowledgement of the detected wake-word on the one or more speakers, activating either (a) a first sound canceller or (b) a second sound canceller, wherein activating either the (a) first sound canceller or (b) the second sound canceller comprises;

when the one or more speakers are playing back audio content, activating the first sound canceller, the first sound canceller configured to cancel audio output from the one or more speakers in a full audible frequency spectrum; and

when the one or more speakers are idle, activating the second sound canceller, the second sound canceller configured to cancel audio output from the one or more speakers in the identified frequency bands of the full audible frequency spectrum in which the audible tone in acknowledgment of the detected wake-word has content;

in response to detecting the wake-word for the voice service and after activating either (a) the first sound canceller or (b) the second sound canceller, outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers;

capturing, via the one or more microphones, second audio within the acoustic environment, wherein the second audio comprises sound produced by the one or more speakers in outputting the audible tone in acknowledgement of the detected wake-word; and

cancelling the audible tone in acknowledgement of the detected wake-word from the captured second audio using the activated sound canceller.

2. The system of claim 1, wherein detecting, within the captured first audio, the wake-word for the voice service comprises triggering an event detector in response to detecting the wake-word, and wherein the operations further comprise resetting the event detector upon detecting a reset event.

3. The system of claim 2, wherein detecting the reset event comprises at least one of:

(i) cancelling the audible tone from the captured second audio using the activated sound canceller;

(ii) expiration of a timer on the activated sound canceller;

(iii) initiation of audio content playback via the one or more speakers;

(iv) cancellation of a voice input corresponding to the wake-word detected within the captured first audio via a control interface;

(v) muting of the one or more microphones; and

(iv) de-activation of the audible tone via the control interface.

4. The system of claim 1, wherein identifying the set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content comprises:

measuring spectral content of the audible tone in the frequency domain;

identifying, from the spectral content of the audible tone in the frequency domain, a set of the frequency bands in which the audible tone has content; and

instructing the second sound canceller to process only the set of frequency bins in which the audible tone has content.

5. The system of claim 1, wherein audio captured by the one or more microphones is divided into frames for processing by either (a) the first sound canceller or (b) the second sound canceller, and wherein activating either (a) the first sound canceller or (b) the second sound canceller before playing the audible tone in acknowledgement of the detected wake-word comprises activating either (a) the first sound canceller or (b) the second sound canceller at least one frame before outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers.

6. The system of claim 1, wherein determining whether the one or more speakers are (a) playing back audio content or (b) idle comprises determining that the one or more speakers are playing back audio content based on an audio stage of the system passing an audio signal representing the audio content.

7. The system of claim 1, wherein the system includes a playback device comprising a network interface and the one or more speakers and a networked-microphone device comprising a network interface, the one or more microphones, the one or more processors, and the data storage storing instructions executable by the one or more processors, and wherein the playback device and the networked-microphone device are connected via the network interface of the playback device and the network interface of the networked-microphone device.

8. The system of claim 1, wherein the system includes a playback device comprising a housing in which the one or more speakers and the one or more microphones are housed.

9. A method to be performed by a system comprising a playback device, the method comprising:

capturing, via one or more microphones, first audio within an acoustic environment;

determining whether one or more speakers of the playback device are (a) playing back audio content or (b) idle;

detecting, within the captured first audio, a wake-word for a voice service;

identifying a set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content;

in response to detecting the wake-word for the voice service and before playing an audible tone in acknowledgement of the detected wake-word on the one or more speakers, activating either (a) a first sound canceller or (b) a second sound canceller, wherein activating either the (a) first sound canceller or (b) the second sound canceller comprises;

when the one or more speakers are playing back audio content, activating the first sound canceller, the first sound canceller configured to cancel audio output from the one or more speakers in a full audible frequency spectrum; and

when the one or more speakers are idle, activating the second sound canceller, the second sound canceller configured to cancel audio output from the one or more speakers in the identified frequency bands of the full audible frequency spectrum in which the audible tone in acknowledgment of the detected wake-word has content;

in response to detecting the wake-word for the voice service and after activating either (a) the first sound canceller or (b) the second sound canceller, outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers;

capturing, via the one or more microphones, second audio within the acoustic environment, wherein the second audio comprises sound produced by the one or more speakers in outputting the audible tone in acknowledgement of the detected wake-word; and

cancelling the audible tone in acknowledgement of the detected wake-word from the captured second audio using the activated sound canceller.

10. The method of claim 9, wherein detecting, within the captured first audio, the wake-word for the voice service comprises triggering an event detector in response to detecting the wake-word, and wherein the method further comprise resetting the event detector upon detecting a reset event.

11. The method of claim 10, wherein detecting the reset event comprises at least one of:

(i) cancelling the audible tone from the captured second audio using the activated sound canceller;

(ii) expiration of a timer on the activated sound canceller;

(iii) initiation of audio content playback via the one or more speakers;

(iv) cancellation of a voice input corresponding to the wake-word detected within the captured first audio via a control interface;

(v) muting of the one or more microphones; and

(iv) de-activation of the audible tone via the control interface.

12. The method of claim 9, wherein identifying the set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content comprises:

measuring spectral content of the audible tone in the frequency domain;

identifying, from the spectral content of the audible tone in the frequency domain, a set of the frequency bands in which the audible tone has content; and

instructing the second sound canceller to process only the set of frequency bins in which the audible tone has content.

13. The method of claim 9, wherein audio captured by the one or more microphones is divided into frames for processing by either (a) the first sound canceller or (b) the second sound canceller, and wherein activating either (a) the first sound canceller or (b) the second sound canceller before playing the audible tone in acknowledgement of the detected wake-word comprises activating either (a) the first sound canceller or (b) the second sound canceller at least one frame before outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers.

14. The method of claim 9, wherein determining whether the one or more speakers are (a) playing back audio content or (b) idle comprises determining that the one or more speakers are playing back audio content based on an audio stage of the system passing an audio signal representing the audio content.

15. A tangible, non-transitory, computer-readable media having stored therein instructions executable by one or more processors to cause a system to perform operations comprising:

capturing, via one or more microphones, first audio within an acoustic environment;

determining whether one or more speakers are (a) playing back audio content or (b) idle;

detecting, within the captured first audio, a wake-word for a voice service;

identifying a set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content;

in response to detecting the wake-word for the voice service and before playing an audible tone in acknowledgement of the detected wake-word on the one or more speakers, activating either (a) a first sound canceller or (b) a second sound canceller, wherein activating either the (a) first sound canceller or (b) the second sound canceller comprises;

when the one or more speakers are playing back audio content, activating the first sound canceller, the first sound canceller configured to cancel audio output from the one or more speakers in a full audible frequency spectrum; and

when the one or more speakers are idle, activating the second sound canceller, the second sound canceller configured to cancel audio output from the one or more speakers in the identified frequency bands of the full audible frequency spectrum in which the audible tone in acknowledgment of the detected wake-word has content;

in response to detecting the wake-word for the voice service and after activating either (a) the first sound canceller or (b) the second sound canceller, outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers;

capturing, via the one or more microphones, second audio within the acoustic environment, wherein the second audio comprises sound produced by the one or more speakers in outputting the audible tone in acknowledgement of the detected wake-word; and

cancelling the audible tone in acknowledgement of the detected wake-word from the captured second audio using the activated sound canceller.

16. The tangible, non-transitory, computer-readable media of claim 15, wherein detecting, within the captured first audio, the wake-word for the voice service comprises triggering an event detector in response to detecting the wake-word, and wherein the operations further comprise resetting the event detector upon detecting a reset event.

17. The tangible, non-transitory, computer-readable media of claim 16, wherein detecting the reset event comprises at least one of:

(i) cancelling the audible tone from the captured second audio using the activated sound canceller;

(ii) expiration of a timer on the activated sound canceller;

(iii) initiation of audio content playback via the one or more speakers;

(iv) cancellation of a voice input corresponding to the wake-word detected within the captured first audio via a control interface;

(v) muting of the one or more microphones; and

(iv) de-activation of the audible tone via the control interface.

18. The tangible, non-transitory, computer-readable media of claim 15, wherein identifying the set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content comprises:

measuring spectral content of the audible tone in the frequency domain;

identifying, from the spectral content of the audible tone in the frequency domain, a set of the frequency bands in which the audible tone has content; and

instructing the second sound canceller to process only the set of frequency bins in which the audible tone has content.

19. The tangible, non-transitory, computer-readable media of claim 15, wherein audio captured by the one or more microphones is divided into frames for processing by either (a) the first sound canceller or (b) the second sound canceller, and wherein activating either (a) the first sound canceller or (b) the second sound canceller before playing the audible tone in acknowledgement of the detected wake-word comprises activating either (a) the first sound canceller or (b) the second sound canceller at least one frame before outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers.

20. The tangible, non-transitory, computer-readable media of claim 15, wherein determining whether the one or more speakers are (a) playing back audio content or (b) idle comprises determining that the one or more speakers are playing back audio content based on an audio stage of the system passing an audio signal representing the audio content.