Apparatus and method of active noise cancellation in a personal listening device

• US 9,706,288 B2
• Filed: 03/12/2015
• Issued: 07/11/2017
• Est. Priority Date: 03/12/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Terlizzi, Jeffrey
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): FAHNERT, FRIEDRICH
• Application Number:
  US14/656,443
• Publication Number:
  US 20160267898A1
• Time in Patent Office: 852 Days
• Field of Search: 381 716, 381 711, 381 74, 381370, 381 98, 381 7111, 702141
• CPC Class Codes: G10K 11/17823 Reference signals, e.g. ambient acoustic environment
• CPC Class Codes: G10K 11/1783 handling or detecting of non-standard events or conditions, e.g. changing operating modes under specific operating conditions
• CPC Class Codes: G10K 11/17833 by using a self-diagnostic function or a malfunction prevention function, e.g. detecting abnormal output levels
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17883 the reference signal being derived from a machine operating condition, e.g. engine RPM or vehicle speed
• CPC Class Codes: G10K 11/17885 additionally using a desired external signal, e.g. pass-through audio such as music or speech
• CPC Class Codes: G10K 2210/1081 Earphones, e.g. for telephones, ear protectors or headsets
• CPC Class Codes: G10K 2210/129 Vibration, e.g. instead of, or in addition to, acoustic noise
• CPC Class Codes: G10K 2210/3226 Sensor details, e.g. for producing a reference or error signal
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 1/1091 Details not provided for in groups H04R1/1008 - H04R1/1083
• CPC Class Codes: H04R 2460/01 Hearing devices using active noise cancellation

Abstract

Personal listening device (PLD) includes earphone housing having therein (a) inertial sensor to detect motion of PLD and to generate motion signal, (b) pressure sensor to detect compression of portion of PLD and to generate pressure sensor signal, and (c) speaker to receive anti-noise signal and desired audio signal from electronic device, and active noise control (ANC) system to generate anti-noise signal as being one of first or second anti-noise signal. ANC system includes processor, vibration detector to detect vibration of the PLD based on at least one of motion signal or pressure sensor signal, and ANC anti-noise generator to generate first anti-noise signal when vibrations are not detected by vibration detector, and to generate second anti-noise signal when vibrations are detected by vibration detector. Second anti-noise signal is based on detected vibrations. Processor reconfigures ANC system for ANC anti-noise generator to generate second anti-noise signal. Other embodiments are described.

Claims

1. A personal listening device (PLD) comprising:

an earphone housing having therein (a) an inertial sensor to detect motion of the PLD and to generate a motion signal, (b) a pressure sensor to detect compression of a portion of the PLD and to generate pressure sensor signal, and (c) a speaker to receive an anti-noise signal and a desired audio signal from an electronic device; and

an active noise control (ANC) system to generate the anti-noise signal as being one of a first anti-noise signal or a second anti-noise signal, the ANC system includes

a processor,

a vibration detector coupled to the processor, the vibration detector to detect a vibration of the PLD based on at least one of the motion signal or the pressure sensor signal, and

an ANC anti-noise generator coupled to the processor, the ANC anti-noise generator to generate the first anti-noise signal when vibrations are not detected by the vibration detector, and to generate the second anti-noise signal when vibrations are detected by the vibration detector, the second anti-noise signal being based on detected vibrations,

wherein the processor reconfigures the ANC system for the ANC anti-noise generator to generate the second anti-noise signal.

2. The PLD in claim 1, wherein the inertial sensor comprises at least one of an accelerometer, a gyroscope, or a microelectromechanical system (MEMS), wherein the inertial sensor detects motion in at least three axes:

x-axis, y-axis, z-axis.

3. The PLD in claim 1, wherein the first anti-noise signal is based on at least one of a reference microphone signal or an error microphone signal.

4. The PLD in claim 3, wherein the ANC system comprises a memory device:

to store a plurality of predetermined sensor data patterns including patterns that indicate the contexts of;

walking, jumping, running, and vehicle motions or vibrations.

5. The PLD in claim 4, wherein the vibration detector is coupled to the memory device and wherein the vibration detector to detect the vibration comprises:

the vibration detector matching at least one of the motion signal or the pressure sensor signal with at least one of the predetermined sensor data patterns.

6. The PLD of claim 5, wherein the processor reconfiguring the ANC system comprises:

the processor locking filter coefficients of an adaptive filter included in the ANC system or locking filtering by the adaptive filter included in the ANC system.

7. The PLD of claim 5, wherein the processor reconfiguring the ANC system comprises:

the processor changing a speed of updates made to an adaptive filter by an adaptive filter controller included in the ANC system.

8. The PLD of claim 5, wherein the processor reconfiguring the ANC system comprises:

the processor selecting predetermined adaptive filter coefficients associated with the at least one of the predetermined sensor data patterns, wherein the predetermined coefficients are stored in the memory device, and

the processor overriding filter coefficients of an adaptive filter, that were computed by an adaptive filter controller included in the ANC system, with the predetermined filter coefficients.

9. The PLD of claim 5, wherein the processor reconfiguring the ANC system comprises:

the processor applying a jacket on filter coefficients of an adaptive filter included in the ANC system.

10. The PLD of claim 5, wherein the processor reconfiguring the ANC system comprises:

the processor muting the anti-noise signal output from the speaker.

11. A method of active noise cancellation in a personal listening device (PLD) comprising:

receiving by an active noise control (ANC) system a reference microphone acoustic signal and an error microphone acoustic signal from the PLD;

receiving by the ANC system at least one of a motion signal or a pressure sensor signal from the PLD, wherein the motion signal is based on a detected motion of the PLD and the pressure sensor signal is based on a detected compression of a portion of the PLD;

determining by the ANC system whether vibrations of the PLD are detected based on at least one of the motion signal or the pressure sensor signal;

when vibrations are not detected, generating by the ANC system a first anti-noise signal based on the reference microphone acoustic signal and the error microphone acoustic signal; and

when vibrations are detected, generating by the ANC system a second anti-noise signal, wherein generating by the ANC system the second anti-noise signal includes reconfiguring the ANC system.

12. The method of claim 11, wherein determining by the ANC system whether vibrations of the PLD system are detected comprises:

the ANC system matching at least one of the motion signal or the pressure sensor signal with at least one of a plurality of predetermined sensor data patterns.

13. The method of claim 12, wherein the plurality of predetermined sensor data patterns are stored in a memory device included in the ANC system.

14. The method of claim 13, wherein the plurality of predetermined sensor data patterns include patterns that indicate the contexts of walking, jumping, running, and vehicle motions or vibrations.

15. The method of claim 14, wherein reconfiguring the ANC system comprises:

locking filter coefficients of an adaptive filter included in the ANC system.

16. The method of claim 14, wherein reconfiguring the ANC system comprises:

changing a speed of updates made to an adaptive filter by an adaptive filter controller included in the ANC system.

17. The method of claim 14, wherein reconfiguring the ANC system comprises:

selecting predetermined adaptive filter coefficients associated with the at least one of the predetermined sensor data patterns, wherein the predetermined coefficients are stored in the memory device, and

a processor overriding filter coefficients of an adaptive filter, that were computed by an adaptive filter controller included in the ANC system, with the predetermined filter coefficients.

18. The method of claim 14, wherein reconfiguring the ANC system comprises:

a processor applying a jacket on filter coefficients of an adaptive filter included in the ANC system.

19. A computer-readable non-transitory storage medium having stored therein instructions, when executed by a processor, causes an active noise control (ANC) system to perform a method of active noise cancellation in a personal listening device (PLD), the method comprising:

receiving a reference microphone acoustic signal and an error microphone acoustic signal from the PLD;

receiving at least one of a motion signal or a pressure sensor signal from the PLD, wherein the motion signal is based on a detected motion of the PLD and the pressure sensor signal is based on a detected compression of a portion of the PLD;

determining whether vibrations of the PLD are detected based on at least one of the motion signal or the pressure sensor signal;

when vibrations are not detected, generating a first anti-noise signal based on the reference microphone acoustic signal and the error microphone acoustic signal; and

when vibrations are detected, generating a second anti-noise signal, wherein the processor reconfigures the ANC system to generate the second anti-noise signal.

20. The computer-readable non-transitory storage medium of claim 19, wherein the ANC system is included in an electronic device coupled to the PDL, the electronic device transmitting an audio signal to the PDL.

21. The computer-readable non-transitory storage medium of claim 19, wherein the ANC system is included in the PDL.