Calibration of a playback device based on an estimated frequency response

• US 10,459,684 B2
• Filed: 08/05/2016
• Issued: 10/29/2019
• Est. Priority Date: 08/05/2016
• Status: Active Grant

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Shih, Shao-Fu, McPherson, Patrick
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): Mohammed, Assad
• Application Number:
  US15/229,693
• Publication Number:
  US 20180039474A1
• Time in Patent Office: 1,180 Days
• CPC Class Codes: G06F 3/165 Management of the audio stream, e.g. setting of volume, audio stream path
• CPC Class Codes: H04R 2227/003 Digital PA systems using, e.g. LAN or internet
• CPC Class Codes: H04R 2227/005 Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 2227/007 Electronic adaptation of audio signals to reverberation of the listening space for PA
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• 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 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone

Abstract

A first stream and second stream of audio are received. The first stream of audio may comprise source audio content to be played back by the audio playback device. The second stream of audio may comprise a recording of an audio signal output by the audio playback device based on the audio playback device playing the source audio content. An estimated frequency response of an audio playback device may be calculated based on the received first stream of audio and the received second stream of audio. Acoustics of the audio playback device may be adjusted based on the estimated frequency response.

Claims

1. A method comprising:

receiving, via a wide area network (WAN), a first stream of audio comprising source audio content to be played back by an audio playback device located in a given room;

receiving a second stream of audio comprising a recording of an audio signal output by the audio playback device in the given room based on the audio playback device playing the source audio content, wherein the second stream of audio is recorded via one or more microphones on the audio playback device;

determining a transfer function between a frequency-domain representation of a frequency response of the first stream of audio and a frequency-domain representation of a frequency response of the second stream of audio;

calculating an estimated frequency response of the audio playback device in the given room based on (i) the transfer function and (ii) a self-response of the audio playback device in an anechoic chamber, wherein the self-response of the audio playback device in the anechoic chamber is stored in a memory of the audio playback device; and

adjusting an acoustic response of the audio playback device based on the estimated frequency response of the audio playback device in the given room.

2. The method of claim 1, wherein determining the transfer function between the frequency-domain representation of the frequency response of the first stream of audio and the frequency-domain representation of the frequency response of the second stream of audio comprises determining whether the transfer function has converged.

3. The method of claim 1, wherein the estimated frequency response of the audio playback device is calculated based on an acoustic echo cancellation algorithm.

4. The method of claim 1, wherein receiving, via the WAN, the first stream of audio comprises receiving, via the WAN, music from a music service provider.

5. The method of claim 1, further comprising:

determining that the audio playback device has changed at least one of spatial location and orientation and wherein calculating the estimated frequency response comprises calculating the estimated frequency response in response to determining that the audio playback device has changed at least one of spatial location and orientation.

6. The method of claim 1, further comprising determining a spectral coverage of the source audio content prior to calculating the estimated frequency response.

7. The method of claim 1, further comprising playing back the source audio content based on the adjusted acoustics.

15. The method of claim 1, wherein adjusting the acoustic response of the audio playback device based on the estimated frequency response of the audio playback device in the given room comprises adjusting acoustics of the audio playback device based on an audio processing algorithm that is selected from a database of audio processing algorithms based on the estimated frequency response.

17. The method of claim 1, further comprising:

determining that the audio playback device is bonded to a second audio playback device to form a bonded zone in which the audio playback device plays the source audio content in synchrony with the second audio playback device, and

wherein calculating the estimated frequency response comprises calculating the estimated frequency response in response to determining that the audio playback device is bonded to the second audio playback device to form the bonded zone.

19. The method of claim 1, wherein the estimated frequency response is an estimated sound pressure level output of the audio playback device as a function of input frequency.

20. The method of claim 1, wherein the self-response of the audio playback device in the anechoic chamber is determined during a testing phase of another audio playback device that is similar to the audio playback device.

8. A tangible non-transitory computer readable storage medium including instructions executable by a processor to cause the processor to implement a method comprising:

receiving, via a wide area network (WAN), a first stream of audio comprising source audio content to be played back by an audio playback device located in a given room;

receiving a second stream of audio comprising a recording of an audio signal output by the audio playback device in the given room based on the audio playback device playing the source audio content, wherein the second stream of audio is recorded via one or more microphones on the audio playback device;

determining a transfer function between a frequency-domain representation of a frequency response of the first stream of audio and a frequency-domain representation of a frequency response of the second stream of audio;

calculating an estimated frequency response of the audio playback device in the given room based on (i) the transfer function and (ii) a self-response of the audio playback device in an anechoic chamber, wherein the self-response of the audio playback device in the anechoic chamber is stored in a memory of the audio playback device; and

adjusting acoustics of the audio playback device based on the estimated frequency response of the audio playback device in the given room.

9. The tangible non-transitory computer readable storage of claim 8, wherein the instructions for determining the transfer function between the frequency-domain representation of the frequency response of the first stream of audio and the frequency-domain representation of the frequency response of the second stream of audio comprises determining whether the transfer function has converged.

10. The tangible non-transitory computer readable storage of claim 8, further comprising instructions for determining that the audio playback device has changed at least one of spatial location and orientation and wherein calculating the estimated frequency response comprises calculating the estimated frequency response in response to determining that the audio playback device has changed at least one of spatial location and orientation.

11. The tangible non-transitory computer readable storage of claim 8, further comprising instructions for determining a spectral coverage of the source audio content prior to calculating the estimated frequency response.

12. The tangible non-transitory computer readable storage of claim 8, further comprising instructions for playing back the source audio content based on the adjusted acoustics.

13. The tangible non-transitory computer readable storage of claim 8, wherein the instructions for receiving, via the WAN, the first stream of audio comprises receiving music from a music service provider via the WAN.

14. The tangible non-transitory computer readable storage of claim 8, wherein the estimated frequency response of the audio playback device is calculated based on an acoustic echo cancellation algorithm.

16. The tangible non-transitory computer readable storage of claim 8, wherein the instructions for adjusting the acoustic response of the audio playback device based on the estimated frequency response of the audio playback device in the given room comprises adjusting acoustics of the audio playback device based on an audio processing algorithm that is selected from a database of audio processing algorithms based on the estimated frequency response.

18. The tangible non-transitory computer readable storage of claim 8, further comprising instructions for determining that the audio playback device is bonded to a second audio playback device to form a bonded zone in which the audio playback device plays the source audio content in synchrony with the second audio playback device,

wherein calculating the estimated frequency response comprises calculating the estimated frequency response in response to determining that the audio playback device is bonded to the second audio playback device to form the bonded zone.

21. The tangible non-transitory computer readable storage of claim 8, wherein the estimated frequency response is an estimated sound pressure level output of the audio playback device as a function of input frequency.

22. The tangible non-transitory computer readable storage of claim 8, wherein the self-response of the audio playback device in the anechoic chamber is determined during a testing phase of another audio playback device that is similar to the audio playback device.