Near-field noise cancellation

• US 9,183,844 B2
• Filed: 05/22/2012
• Issued: 11/10/2015
• Est. Priority Date: 05/22/2012
• Status: Active Grant

• Current Assignee: Harris Global Communications, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Tennant, Bryce
• Primary Examiner(s): Breene, John
• Assistant Examiner(s): Aiello, Jeffrey
• Application Number:
  US13/477,154
• Publication Number:
  US 20130317783A1
• Time in Patent Office: 1,267 Days
• Field of Search: 381/71.1, 381/73.1, 381/92, 381/94.1, 455/41.1, 455/63.1, 702/191
• US Class Current: 1/1
• CPC Class Codes: G10L 21/0208 Noise filtering

Abstract

Systems and methods for cancelling a near-field noise signal. The methods generally involve: receiving (604), from a first acoustic sensing device (120), a first signal (214) comprising a near-field noise signal (206); synthesizing (320, 420, 520, 606) a replica signal (322, 422, 522) which replicates the near-field noise signal; and communicating (608) the replica signal and the first signal to a far-field noise cancellation process (150). Prior to communicating the replica signal to the far-field noise cancellation process, at least one characteristic of the replica signal is controlled (606) so that the far-field noise cancellation process will identify the near-field noise signal as far-field noise. The far-field noise cancellation process cancels (610) the near-field noise signal and generates (612) an output signal (360, 460, 560) in which the near-field noise signal is reduced in amplitude.

Claims

1. A method for reducing an interference of a near-field noise signal with a select near-field sound, the method comprising:

receiving, from a first acoustic sensing device, a first electronic signal comprising the select near-field sound signal and the near-field noise signal including near-field noise originating from at least one first sound source located relatively proximal to the first acoustic sensing device as compared to a second sound source from which a far-field noise originates;

analyzing the first electronic signal to detect the near-field noise signal based on a known recognizable acoustic signature or pattern of the first sound source which was known prior to the near-field noise'"'"'s origination;

generating a replica signal when a presence of the near-field noise signal is detected within the first electronic signal, where the replica signal is a replica of the near-field noise signal;

controlling at least one characteristic of the replica signal so as to cause a far-field noise cancellation process to consider the corresponding near-field noise as constituting far-field noise;

communicating said replica signal to a first input of a far-field noise cancellation process and said first electronic signal to a second input of the far-field noise cancellation process, where the far-field noise cancellation process is designed to cancel far-field noise from audio signals while preserving near-field sound; and

generating an output signal of said far-field noise cancellation process in which said near-field noise signal is reduced in amplitude whereby the interference thereof with the select near-field sound signal is also reduced.

2. The method according to claim 1, further comprising:

receiving an electronic trigger signal for said near-field noise signal; and

controlling a timing of said replica signal based on said electronic trigger signal.

3. The method according to claim 1, wherein said first electronic signal further includes a speech signal originating in a near field of said first acoustic sensing device, and said far-field noise cancellation process preserves said speech signal in said output signal.

4. The method according to claim 3, further comprising:

receiving, from a second acoustic sensing device, a second electronic signal; and

prior to said communicating step, adding said second electronic signal to said replica signal;

wherein said speech signal is also included in said second electronic signal in a form that is attenuated relative to said speech signal in said first electronic signal.

5. The method according to claim 4, wherein said first electronic signal and said second electronic signal include a far-field noise signal, and wherein said far-field noise signal is substantially reduced in said output signal.

6. The method according to claim 1, wherein a timing of said replica signal is controlled.

7. The method according to claim 6, wherein a periodicity of said replica signal is controlled.

8. The method according to claim 1, wherein said near-field noise signal is produced by pulsating an air flow in an SCBA mask.

9. The method according to claim 1, wherein said near-field noise signal is a quasi-periodic signal.

10. The method according to claim 1, wherein said analyzing step comprises comparing said near-field noise signal to stored information concerning a model near-field noise signal.

11. A communications device comprising:

a first acoustic sensing device configured to receive acoustic signals and generate a first electronic signal based on said acoustic signals;

a far field noise cancellation device comprising a primary input and a secondary input, and configured to reduce interference of received near-field noise signals identified as far-field noise with select near-field sound signals; and

at least one electronic circuit configured to;

receive, from said first acoustic sensing device, said first electronic signal comprising a select near-field sound signal and a near-field noise signal including near-field noise originating from at least one first sound source located relatively proximal to the first acoustic sensing device as compared to a second sound source from which a far-field noise originates;

analyze the first electronic signal to detect the near-field noise signal based on a known recognizable acoustic signature or pattern of the first sound source which was known prior to the near-field noise'"'"'s origination;

generating a replica signal when a presence of the near-field noise signal is detected within the first electronic signal, where the replica signal is a replica of the near-field noise signal;

control at least one characteristic of said replica signal so as to cause said far-field noise cancellation device to consider said near-field noise signal as constituting far-field noise; and

communicate said first electronic signal to said primary input and said replica signal to said secondary input of said far-field noise cancellation device.

12. The communications device according to claim 11, wherein said electronic circuit is further configured to:

receive an electronic trigger signal for said near-field noise signal; and

generate said replica signal based on said electronic trigger signal.

13. The communications device according to claim 11, wherein said first electronic signal includes an electronic representation of a speech signal originating in a near field of said first acoustic sensing device, and said far-field noise cancellation device is further configured to generate an output signal that includes said speech signal.

14. The communications device according to claim 13, wherein said electronic circuit is further configured to:

receive, from a second acoustic sensing device, a second electronic signal comprising said speech signal in a form that is attenuated relative to said speech signal in said first electronic signal; and

prior to said communicating step, adding said second electronic signal to said replica signal.

15. The communications device according to claim 14, wherein said first electronic signal and said second electronic signal include an electronic representation of a far-field noise signal originating in a far field of said first and said second acoustic sensing devices, and wherein said far-field noise signal is substantially reduced in said output signal.

16. The communications device according to claim 11, wherein said electronic circuit is further configured to control a timing of said replica signal.

17. The communications device according to claim 11, wherein said electronic circuit is further configured to control a periodicity of said replica signal.

18. The communications device according to claim 11, wherein said near-field noise signal is produced by pulsating an air flow in an SCBA mask.

19. The communications device according to claim 11, wherein said near-field noise signal is a quasi-periodic signal.

20. The communications device according to claim 11, wherein said electronic circuit is configured to identify the presence of said near-field noise signal in said first electronic signal by comparing said near-field noise signal to stored information concerning a model near-field noise signal.

21. A device comprising a non-transitory computer-readable storage medium, having stored thereon a computer program for reducing an interference of a near-field noise signal with a select near-field sound signal, the computer program having a plurality of code sections, the code sections executable by a computing device to cause the computing device to perform the steps of:

receiving, from a first acoustic sensing device, a first electronic signal comprising the select near-field sound signal and the near-field noise signal including near-field noise originating from at least one first sound source located relatively proximal to the first acoustic sensing device as compared to a second sound source from which a far-field noise originates;

analyzing the first electronic signal to detect the near-field noise signal based on a known recognizable acoustic signature or pattern of the first sound source which was known prior to the near-field noise'"'"'s origination;

generating a replica signal when a presence of the near-field noise signal is detected within the first electronic signal, where the replica signal is a replica of the near-field noise signal;

controlling at least one characteristic of the replica signal so as to cause a far-field noise cancellation process to consider the corresponding near-field noise as constituting far-field noise;

communicating said replica signal to a first input of a far-field noise cancellation process and said first electronic signal to a second input of the far-field noise cancellation process, where the far-field noise cancellation process is designed to cancel far-field noise from audio signals while preserving near-field sound; and

generating an output signal of said far-field noise cancellation process in which said near-field noise signal is reduced in amplitude whereby the interference thereof with the select near-field sound signal is also reduced.