Feedback cancelation for enhanced conversational communications in shared acoustic space

• US 9,672,805 B2
• Filed: 07/24/2015
• Issued: 06/06/2017
• Est. Priority Date: 12/12/2014
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kim, Lae-Hoon, Visser, Erik, Mohammad, Asif Iqbal
• Primary Examiner(s): HOLDER, REGINA NEAL
• Application Number:
  US14/808,746
• Publication Number:
  US 20160171964A1
• Time in Patent Office: 683 Days
• CPC Class Codes: G10K 11/178 by electro-acoustically regenerating the original acoustic waves in anti-phase
• CPC Class Codes: G10L 2021/02082 the noise being echo, reverberation of the speech
• CPC Class Codes: G10L 21/02 Speech enhancement, e.g. noise reduction or echo cancellation reducing echo effects in line transmission systems H04B3/20; echo suppression in hands-free telephones H04M9/08
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23
• CPC Class Codes: H04R 2227/009 Signal processing in [PA] systems to enhance the speech intelligibility
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• 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 3/02 for preventing acoustic reaction , i.e. acoustic oscillatory feedback specially adapted for hearing aids H04R25/453
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• CPC Class Codes: H04S 7/00 Indicating arrangements; Control arrangements, e.g. balance control
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence

Abstract

A crosstalk cancelation technique reduces feedback in a shared acoustic space by canceling out some or all parts of sound signals that would otherwise be produced by a loudspeaker to only be captured by a microphone that, recursively, would cause these sounds signals to be reproduced again on the loudspeaker as feedback. Crosstalk cancelation can be used in a multichannel acoustic system (MAS) comprising an arrangement of microphones, loudspeakers, and a processor to together enhance conversational speech between in a shared acoustic space. To achieve crosstalk cancelation, a processor analyzes the inputs of each microphone, compares it to the output of far loudspeaker(s) relative to each such microphone, and cancels out any portion of a sound signal received by the microphone that matches signals that were just produced by the far loudspeaker(s) and sending only the remaining sound signal (if any) to such far loudspeakers.

Claims

1. A method for providing crosstalk cancelation in a shared acoustic space, the method comprising:

receiving, at a first adaptive filter, a first set of sound signals detected by a first microphone in a first zone, the first set of sound signals produced by a first loudspeaker in the first zone;

receiving, at the first adaptive filter, a second set of sound signals detected by a second microphone in a second zone, the second set of sound signals including components of the first set of sound signals;

determining a first value associated with the first set of sound signals;

determining a second value associated with the second set of sound signals;

filtering, at the first adaptive filter, the second set of sound signals to cancel the components of the first set of sound signals included in the second set of sound signals, the filtering being based on the first set of sound signals received from the first microphone and based on determining that a ratio of the second value to the first value exceeds a threshold value; and

sending, by the first adaptive filter, the filtered second set of sound signals to the first loudspeaker.

2. The method of claim 1, wherein sound signals detected at the first microphone in the first zone are produced on one or more loudspeakers in each zone that together comprise a plurality of zones corresponding to the shared acoustic space, and wherein the filtering includes reducing the filtered second set of sound signals proportional to the ratio of the second value to the first value.

3. The method of claim 2, further comprising:

using a multichannel acoustic system comprising a plurality of microphones and a plurality of loudspeakers, the plurality of zones comprising at least the first zone and the second zone, to calibrate the first adaptive filter, prior to filtering the second set of sound signals, by;

playing a sound on each of the one or more loudspeakers in each zone of the plurality of zones, and recording a response by each of the plurality of microphones, and wherein the second set of sound signals are filtered based on the plurality of recordings.

4. The method of claim 3, wherein the shared acoustic space is one of an interior passenger compartment of a transportation vehicle for persons and a non-transportation shared acoustic space, and wherein calibrating, using the multichannel acoustic system, is done without persons in the shared acoustic space.

5. The method of claim 4, wherein the shared acoustic space is an interior passenger compartment of a vehicle, wherein the plurality of loudspeakers corresponds to a plurality of seats in the vehicle, and wherein the plurality of microphones also corresponds to the plurality of seats, wherein using the multichannel acoustic system to calibrate the first adaptive filter includes determining a set of possible combinations of persons occupying the plurality of seats, one person per seat, and recording a response by each of the plurality of microphones for each combination of the set of possible combinations.

6. The method of claim 5, wherein the multichannel acoustic system associates a first passenger seated in a front row of the vehicle with a microphone and a loudspeaker for the zone in which the first passenger is located, wherein one loudspeaker corresponds to one seat, and wherein one microphone corresponds to one seat.

7. The method of claim 1, further comprising:

receiving, at a second adaptive filter, a third set of sound signals detected by the second microphone in the second zone, the third set of sound signals produced by a second loudspeaker in the second zone;

receiving, at the second adaptive filter, a fourth set of sound signals detected by the first microphone in the first zone, the fourth set of sound signals including components of the third set of sound signals;

filtering, at the second adaptive filter, the fourth set of sound signals to cancel the components of the third set of sound signals included in the fourth set of sound signals, the filtering being based on a second reference sound output received from the second microphone; and

sending, by the second adaptive filter, the filtered fourth set of sound signals to the second loudspeaker.

8. A multichannel acoustic system for crosstalk cancelation in a multi-zone shared acoustic space, the system comprising:

a first loudspeaker located in a first zone configured to produce a first set of sound signals;

a first microphone located in the first zone configured to detect the first set of sound signals;

a second microphone in a second zone configured to detect a second set of sound signals, the second set of sound signals including components of the first set of sound signals; and

a first adaptive filter coupled to the first microphone, the second microphone, the first loudspeaker, and a second loudspeaker, the first adaptive filter configured to;

determining a first value associated with the first set of sound signals;

determining a second value associated with the second set of sound signals;

filter the second set of sound signals to cancel the components of the first set of sound signals from the second set of sound signals, the filtering being based on a first reference sound output received from the first microphone and based on determining that a ratio of the second value to the first value exceeds a threshold value; and

transmit the filtered second set of sound signals to the first loudspeaker.

9. The system of claim 8, wherein sound signals detected at the first microphone in the first zone are produced on one or more loudspeakers in each zone that together comprise a plurality of zones corresponding to the shared acoustic space.

10. The system of claim 9, wherein the crosstalk cancelation is utilized by a multichannel acoustic system operating within the shared acoustic space, the multichannel acoustic system comprising a plurality of microphones and a plurality of loudspeakers, the plurality of zones comprising at least the first zone and the second zone.

11. The system of claim 10, wherein the shared acoustic space is one of an interior passenger compartment of a transportation vehicle for persons and a non-transportation shared acoustic space.

12. The system of claim 11, wherein the shared acoustic space is an interior passenger compartment of a vehicle, wherein the plurality of loudspeakers corresponds to a plurality of seats in the vehicle, and wherein the plurality of microphones also corresponds to the plurality of seats.

13. The system of claim 12, wherein the multichannel acoustic system associates a first passenger seated in a front row of the vehicle with a microphone and a loudspeaker for the zone in which the first passenger is located.

14. The system of claim 8, further comprising:

a second loudspeaker in the second zone configured to produce a third set of sound signals; and

a second adaptive filter coupled to the first microphone, the second microphone, the first loudspeaker, and the second loudspeaker, the second adaptive filter configured to;

receive a fourth set of sound signals detected by the first microphone, the fourth set of sound signals comprising components of the third set of sound signals detected by the first microphone;

filter the fourth set of sound signals to cancel the components of the third set of sound signals, the filtering being based on the second reference sound output received from the second microphone; and

transmit the filtered fourth set of sound signals to the second loudspeaker.

15. An apparatus for providing crosstalk cancelation in a shared acoustic space, the apparatus comprising:

means for receiving, at a first adaptive filter, a first set of sound signals detected by a first microphone in a first zone, the first set of sound signals produced by a first loudspeaker in the first zone;

means for receiving, at the first adaptive filter, a second set of sound signals detected by a second microphone in a second zone, the second set of sound signals including components of the first set of sound signals;

means for determining a first value associated with the first set of sound signals;

means for detetinining a second value associated with the second set of sound signals;

means for filtering, at the first adaptive filter, the second set of sound signals to cancel the components of the first set of sound signals included in the second set of sound signals, the filtering being based on the first set of sound signals received from the first microphone and based on determining that a ratio of the second value to the first value exceeds a threshold value; and

means for sending, by the first adaptive filter, the filtered second set of sound signals to the first loudspeaker.

16. The apparatus of claim 15, wherein sound signals detected at the first microphone in the first zone are produced on one or more loudspeakers in each zone that together comprise a plurality of zones corresponding to the shared acoustic space.

17. The apparatus of claim 16, wherein the crosstalk cancelation is utilized by a multichannel acoustic system operating within the shared acoustic space, the multichannel acoustic system comprising a plurality of microphones and a plurality of loudspeakers, the plurality of zones comprising at least the first zone and the second zone.

18. The apparatus of claim 17, wherein the shared acoustic space is one of an interior passenger compartment of a transportation vehicle for persons and a non-transportation shared acoustic space.

19. The apparatus of claim 18, wherein the shared acoustic space is an interior passenger compartment of a vehicle, wherein the plurality of loudspeakers corresponds to a plurality of seats in the vehicle, and wherein the plurality of microphones also corresponds to the plurality of seats.

20. The apparatus of claim 19, wherein the apparatus associates a first passenger seated in a front row of the vehicle with a microphone and a loudspeaker for the zone in which the first passenger is located.

21. The apparatus of claim 15, further comprising:

means for receiving, at a second adaptive filter, a third set of sound signals detected by the second microphone in the second zone, the third set of sound signals produced by a second loudspeaker in the second zone;

means for receiving, at the second adaptive filter, a fourth set of sound signals detected by the first microphone in the first zone, the fourth set of sound signals including components of the third set of sound signals;

means for filtering, at the second adaptive filter, the fourth set of sound signals to cancel the components of the third set of sound signals included in the fourth set of sound signals, the filtering being based on a second reference sound output received from the second microphone; and

means for sending, by the second adaptive filter, the filtered fourth set of sound signals to the second loudspeaker.

22. A non-transitory computer readable medium comprising computer-executable instructions for providing crosstalk cancelation in a shared acoustic space, the computer-executable instructions comprising instructions for:

receiving, at a first adaptive filter, a first set of sound signals detected by a first microphone in a first zone, the first set of sound signals produced by a first loudspeaker in the first zone;

receiving, at the first adaptive filter, a second set of sound signals detected by a second microphone in a second zone, the second set of sound signals including components of the first set of sound signals;

determining a first value associated with the first set of sound signals;

determining a second value associated with the second set of sound signals;

filtering, at the first adaptive filter, the second set of sound signals to cancel the components of the first set of sound signals included in the second set of sound signals, the filtering being based on the first set of sound signals received from the first microphone and based on determining that a ratio of the second value to the first value exceeds a threshold value; and

sending, by the first adaptive filter, the filtered second set of sound signals to the first loudspeaker.

23. The computer readable medium of claim 22, wherein sound signals detected at the first microphone in the first zone are produced on one or more loudspeakers in each zone that together comprise a plurality of zones corresponding to the shared acoustic space.

24. The computer readable medium of claim 23, wherein the crosstalk cancelation is utilized by a multichannel acoustic system operating within the shared acoustic space, the multichannel acoustic system comprising a plurality of microphones and a plurality of loudspeakers, the plurality of zones comprising at least the first zone and the second zone.

25. The computer readable medium of claim 24, wherein the shared acoustic space is one of an interior passenger compartment of a transportation vehicle for persons and a non-transportation shared acoustic space.

26. The computer readable medium of claim 25, wherein the shared acoustic space is an interior passenger compartment of a vehicle, wherein the plurality of loudspeakers corresponds to a plurality of seats in the vehicle, and wherein the plurality of microphones also corresponds to the plurality of seats.

27. The computer readable medium of claim 26, wherein the instructions associate a first passenger seated in a front row of the vehicle with a microphone and a loudspeaker for the zone in which the first passenger is located.

28. The computer readable medium of claim 22, further comprising instructions for:

receiving, at a second adaptive filter, a third set of sound signals detected by the second microphone in the second zone, the third set of sound signals produced by a second loudspeaker in the second zone;

receiving, at the second adaptive filter, a fourth set of sound signals detected by the first microphone in the first zone, the fourth set of sound signals including components of the third set of sound signals;

filtering, at the second adaptive filter, the fourth set of sound signals to cancel the components of the third set of sound signals included in the fourth set of sound signals, the filtering being based on a second reference sound output received from the second microphone; and

sending, by the second adaptive filter, the filtered fourth set of sound signals to the second loudspeaker.