Facilitating calibration of an audio playback device

• US 10,585,639 B2
• Filed: 11/07/2018
• Issued: 03/10/2020
• Est. Priority Date: 09/17/2015
• Status: Active Grant

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Sheen, Timothy W.
• Primary Examiner(s): Tsang, Fan S
• Assistant Examiner(s): Siegel, David
• Application Number:
  US16/182,886
• Publication Number:
  US 20190073192A1
• Time in Patent Office: 489 Days
• CPC Class Codes: G06F 3/165 Management of the audio stream, e.g. setting of volume, audio stream path
• CPC Class Codes: H03G 5/005 of digital signals
• CPC Class Codes: H03G 5/165 Equalizers; Volume or gain control in limited frequency bands
• CPC Class Codes: H04R 2227/001 Adaptation of signal processing in PA systems in dependence of presence of noise
• CPC Class Codes: H04R 2227/005 Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence
• CPC Class Codes: H04R 29/007 for public address systems public address systems per se H04R27/00
• CPC Class Codes: H04R 3/04 for correcting frequency response
• CPC Class Codes: H04S 2420/07 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation
• CPC Class Codes: H04S 7/307 Frequency adjustment, e.g. tone control H04S7/301 takes precedence

Abstract

Example techniques facilitate calibration of a playback device. An example implementation involves a computing device capturing, via a microphone, data representing multiple iterations of a calibration sound as played by a playback device. The computing device identifies multiple sections within the captured data. Two or more sections represent respective iterations of the calibration sound as played by the playback device. Based on the multiple identified sections, the computing device determines a frequency response of the playback device, the frequency response of the playback device representing audio output by the playback device and acoustic characteristics of an environment around the playback device. Based on the frequency response of the playback device and a target frequency response, the computing device determines one or more parameters of an audio processing algorithm and sends, to the playback device, the one or more parameters of the audio processing algorithm.

Claims

1. A non-transitory computer-readable medium storing instructions that, when executed by a computing device, cause the computing device to perform a method comprising:

capturing, via a microphone of the computing device, data representing multiple iterations of a calibration sound as played by a playback device, wherein the calibration sound includes (i) a first component that includes calibration noise at frequencies between a minimum of a calibration frequency range and a first threshold frequency and (ii) a second component that includes a signal sweeping through frequencies between a second threshold frequency and a maximum of the calibration frequency range;

identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device, wherein two or more sections represent respective iterations of the calibration sound as played by the playback device;

based on the multiple identified sections within the data representing multiple iterations of a calibration sound as played by the playback device, determining a frequency response of the playback device over the calibration frequency range, wherein the frequency response of the playback device represents audio output by the playback device and acoustic characteristics of an environment around the playback device;

based on the frequency response of the playback device and a target frequency response, determining one or more parameters of an audio processing algorithm; and

sending, to the playback device, the one or more parameters of the audio processing algorithm.

2. The non-transitory computer-readable medium of claim 1, wherein the computing device is moving within the environment around the playback device while the computing device is capturing at least a portion of the data representing multiple iterations of a calibration sound as played by the playback device.

3. The non-transitory computer-readable medium of claim 1, wherein the multiple iterations of the calibration sound are separated in time by respective guard bands comprising the first component, and wherein the respective guard bands exclude the second component.

4. The non-transitory computer-readable medium of claim 3, wherein identifying multiple sections within the data representing multiple iterations of the calibration sound as played by the playback device comprise:

identifying one or more first sections of the data that corresponds to the respective guard bands that exclude the second component; and

based on (i) the identified one or more first sections of the data and (ii) a pre-determined periodicity of the calibration sound, identifying one or more second sections of the data that correspond to respective iteration of the calibration sound as played by the playback device.

5. The non-transitory computer-readable medium of claim 3, wherein identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device comprises:

identifying, within the data representing the multiple iterations of the calibration sound, a first section representing a first guard band;

identifying, within the data representing the multiple iterations of a calibration sound, a second section representing a second guard band; and

identifying, within the data representing the multiple iterations of a calibration sound between the first section and the second section, a third section representing a given iteration of the calibration sound.

6. The non-transitory computer-readable medium of claim 3, wherein identifying multiple sections within the data representing the multiple iterations of the calibration sound as played by the playback device comprises:

identifying a portion of the data representing multiple iterations of the calibration sound, the identified portion having a signal-to-noise ratio (SNR) that is greater than a threshold SNR, wherein the SNR of the identified portion is a ratio of (i) a signal level of (a) a given iteration of the calibration sound and/or (b) the guard band to (ii) background noise detected by the microphone within the environment of the playback device;

identifying a sub-section of the identified portion corresponding to the guard band, the sub-section having a sound intensity that is less than a threshold sound intensity; and

identifying one or more sections of the multiple sections based on (i) the identified sub-section of the identified portion and (ii) a predetermined periodicity of the calibration sound.

7. The non-transitory computer-readable medium of claim 3, wherein the method further comprises:

determining respective signal-to-noise ratios (SNR) of a plurality of sections within the data representing the multiple iterations of a calibration sound as played by the playback device, wherein the respective SNRs represent ratios of (i) a signal level of (a) respective iterations of the calibration sound and/or (b) respective iterations of the guard band to (ii) background noise detected by the microphone within the environment of the playback device; and

identifying, as the multiple sections, particular sections having SNRs that exceeds a threshold SNR.

8. The non-transitory computer-readable medium of claim 3, wherein the guard band includes first audio frequency and a second audio frequency at a particular time, and wherein the method further comprises:

detecting the first audio frequency and the second audio frequency at the particular time,

wherein identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device comprises identifying the multiple sections based on (i) detecting the first audio frequency and the second audio frequency at the particular time and (ii) a predetermined periodicity of the calibration sounds.

9. The non-transitory computer-readable medium of claim 1, wherein determining the one or more parameters of the audio processing algorithm comprises limiting at least one parameter of the one or more parameters of the audio processing algorithm to prevent a portion of audio played by the playback device from being amplified by more than a threshold amplification factor when the audio processing algorithm is implemented by the playback device.

10. The non-transitory computer-readable medium of claim 1, wherein the method further comprises:

capturing, via the microphone, one or more additional calibration sounds played by the playback device when implementing the audio processing algorithm; and

based on the captured one or more additional calibration sounds, determining that the playback device is calibrated to the environment around the playback device.

11. A method comprising:

capturing, via a microphone of a computing device, data representing multiple iterations of a calibration sound as played by a playback device, wherein the calibration sound includes (i) a first component that includes calibration noise at frequencies between a minimum of a calibration frequency range and a first threshold frequency and (ii) a second component that includes a signal sweeping through frequencies between a second threshold frequency and a maximum of the calibration frequency range;

identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device, wherein two or more sections represent respective iterations of the calibration sound as played by the playback device;

based on the multiple identified sections within the data representing multiple iterations of a calibration sound as played by the playback device, determining a frequency response of the playback device over the calibration frequency range, wherein the frequency response of the playback device represents audio output by the playback device and acoustic characteristics of an environment around the playback device;

based on the frequency response of the playback device and a target frequency response, determining one or more parameters of an audio processing algorithm; and

sending, to the playback device, the one or more parameters of the audio processing algorithm.

12. The method of claim 11, wherein the computing device is moving within the environment around the playback device while the computing device is capturing at least a portion of the data representing multiple iterations of a calibration sound as played by the playback device.

13. The method of claim 11, wherein the multiple iterations of the calibration sound are separated in time by respective guard bands comprising the first component, and wherein the respective guard bands exclude the second component.

14. The method of claim 13, wherein identifying multiple sections within the data representing multiple iterations of the calibration sound as played by the playback device comprise:

identifying one or more first sections of the data that corresponds to the respective guard bands that exclude the second component; and

based on (i) the identified one or more first sections of the data and (ii) a pre-determined periodicity of the calibration sound, identifying one or more second sections of the data that correspond to respective iteration of the calibration sound as played by the playback device.

15. The method of claim 13, wherein identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device comprises:

identifying, within the data representing the multiple iterations of the calibration sound, a first section representing a first guard band;

identifying, within the data representing the multiple iterations of a calibration sound, a second section representing a second guard band; and

identifying, within the data representing the multiple iterations of a calibration sound between the first section and the second section, a third section representing a given iteration of the calibration sound.

16. The method of claim 13, wherein identifying multiple sections within the data representing the multiple iterations of the calibration sound as played by the playback device comprises:

identifying a portion of the data representing multiple iterations of the calibration sound, the identified portion having a signal-to-noise ratio (SNR) that is greater than a threshold SNR, wherein the SNR of the identified portion is a ratio of (i) a signal level of (a) a given iteration of the calibration sound and/or (b) the guard band to (ii) background noise detected by the microphone within the environment of the playback device;

identifying a sub-section of the identified portion corresponding to the guard band, the sub-section having a sound intensity that is less than a threshold sound intensity; and

identifying one or more sections of the multiple sections based on (i) the identified sub-section of the identified portion and (ii) a predetermined periodicity of the calibration sound.

17. The method of claim 13, wherein the method further comprises:

determining respective signal-to-noise ratios (SNR) of a plurality of sections within the data representing the multiple iterations of a calibration sound as played by the playback device, wherein the respective SNRs represent ratios of (i) a signal level of (a) respective iterations of the calibration sound and/or (b) respective iterations of the guard band to (ii) background noise detected by the microphone within the environment of the playback device; and

identifying, as the multiple sections, particular sections having SNRs that exceeds a threshold SNR.

18. The method of claim 13, wherein the guard band includes first audio frequency and a second audio frequency at a particular time, and wherein the method further comprises:

detecting the first audio frequency and the second audio frequency at the particular time,

wherein identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device comprises identifying the multiple sections based on (i) detecting the first audio frequency and the second audio frequency at the particular time and (ii) a predetermined periodicity of the calibration sounds.

19. The method of claim 11, wherein determining the one or more parameters of the audio processing algorithm comprises limiting at least one parameter of the one or more parameters of the audio processing algorithm to prevent a portion of audio played by the playback device from being amplified by more than a threshold amplification factor when the audio processing algorithm is implemented by the playback device.

20. A mobile device comprising:

a microphone;

a network interface;

one or more processors;

data storage storing instructions that, when executed by the one or more processors, cause the mobile device to perform a method comprising

capturing, via the microphone, data representing multiple iterations of a calibration sound as played by a playback device, wherein the calibration sound includes (i) a first component that includes calibration noise at frequencies between a minimum of a calibration frequency range and a first threshold frequency and (ii) a second component that includes a signal sweeping through frequencies between a second threshold frequency and a maximum of the calibration frequency range;

identifying multiple sections within the data representing the multiple iterations of a calibration sound as played by the playback device, wherein two or more sections represent respective iterations of the calibration sound as played by the playback device;

based on the multiple identified sections within the data representing multiple iterations of a calibration sound as played by the playback device, determining a frequency response of the playback device over the calibration frequency range, wherein the frequency response of the playback device represents audio output by the playback device and acoustic characteristics of an environment around the playback device;

based on the frequency response of the playback device and a target frequency response, determining one or more parameters of an audio processing algorithm; and

sending, to the playback device via the network interface, the one or more parameters of the audio processing algorithm.