HEARING AID COMPATIBLE AUDIO DEVICE WITH ACOUSTIC NOISE CANCELLATION

• US 20130273967A1
• Filed: 04/11/2012
• Published: 10/17/2013
• Est. Priority Date: 04/11/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Dave, Ruchir M., Chen, Shaohai
• Granted Patent: US 9,084,063 B2
• Time in Patent Office: Days
• US Class Current: 455/556.1
• CPC Class Codes: G10K 11/16 Methods or devices for protecting against, or for damping, noise or other acoustic waves in general G10K11/36 takes precedence
• 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 11/17873 using a reference signal without an error signal, e.g. pure feedforward
• 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: G11C 13/00 Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
• CPC Class Codes: G11C 13/0023 Address circuits or decoders
• CPC Class Codes: G11C 13/0061 Timing circuits or methods
• CPC Class Codes: H04M 1/6041 Portable telephones adapted for handsfree use
• CPC Class Codes: H04M 1/72478 for hearing-impaired users
• 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 2225/41 Detection or adaptation of hearing aid parameters or programs to listening situation, e.g. pub, forest
• CPC Class Codes: H04R 2225/49 Reducing the effects of electromagnetic noise on the functioning of hearing aids, by, e.g. shielding, signal processing adaptation, selective (de)activation of electronic parts in hearing aid
• CPC Class Codes: H04R 2225/51 Aspects of antennas or their circuitry in or for hearing aids
• CPC Class Codes: H04R 2460/01 Hearing devices using active noise cancellation
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils

Abstract

A portable audio device, which includes active noise cancellation circuitry, a hearing aid compliant magnetic radiator, and a speaker/earpiece, is surrounded by ambient acoustic noise. The active noise cancellation circuitry provides an anti-noise signal at an input of the speaker to control/reduce the ambient acoustic noise outside of the device. In addition, the active noise cancellation circuitry provides an inverse anti-noise signal to an input of the magnetic radiator. The magnetic fields produced by the speaker driven by the anti-noise signal and the magnetic radiator driven by the inverse anti-noise signal cancel each other out through phase cancellation such that a hearing aid using a telecoil coupled to the audio device does not produce significant audio waves based on either of these signals. Other embodiments are also described.

Claims

1. An audio device, comprising:

a speaker having an input to receive an audio signal;

active noise cancellation (ANC) circuitry to provide an anti-noise signal at the input of the speaker to control ambient acoustic noise outside of the device and to cancel an effect of the anti-noise signal that is in the magnetic field produced by the speaker by generating an inverse anti-noise signal; and

a magnetic field radiator having an input to receive the inverse anti-noise signal.

2. The device of claim 1, wherein the inverse anti-noise signal is generated by inverting the anti-noise signal so that the combined magnetic field produced by the speaker and the radiator, exhibits essentially none of the effects of the anti-noise signal.

3. The device of claim 1, wherein the inverse anti-noise signal is an out-of-phase version of the anti-noise signal.

4. The device of claim 1, further comprising:

one or more microphones to pick up the ambient acoustic noise outside of the device for use by the ANC circuitry.

5. The device of claim 1, wherein the radiator is integrated with the speaker within a housing of the device.

6. The device of claim 1, wherein the anti-noise signal is combined with the audio signal before being provided to the input of the speaker.

7. The device of claim 1, wherein the inverse anti-noise signal is combined with the audio signal before being provided to the input of the radiator.

8. The device of claim 1 further comprising:

wireless network communications circuitry to produce the audio signal as a downlink audio signal; and

a downlink audio processor to enhance the downlink audio signal.

9. A method performed in an audio device, comprising:

receiving an audio signal;

generating a signal that represents background acoustic noise surrounding a user of the device;

generating an anti-noise signal intended to cancel the background acoustic noise;

generating an inverse anti-noise signal that is intended to undo an effect of the anti-noise signal;

converting the audio signal and the anti-noise signal into acoustic form while producing a first magnetic field; and

converting the inverse anti-noise signal into a second magnetic field.

10. The method of claim 9, wherein the inverse anti-noise signal is generated by inverting the anti-noise signal.

11. The method of claim 9, wherein the inverse anti-noise signal is an out-of-phase version of the anti-noise signal such that the effect of the anti-noise signal in a magnetic field signal picked up by a T-coil of a hearing aid worn by the user, is negligible compared to an effect of the audio signal.

12. The method of claim 9, wherein the signal representing the background acoustic surrounding the near-end user of the device is generated using a microphone of the device.

13. The method of claim 9, further comprising combining the anti-noise signal with the audio signal in digital domain, prior to conversion into acoustic form.

14. A mobile phone, comprising:

mobile phone network communications circuitry to generate a downlink audio signal;

an earpiece speaker having an input to receive the downlink audio signal;

a hearing aid compatible (HAC) radiator having an input to receive the downlink audio signal;

active noise cancellation (ANC) circuitry to generate an anti noise signal to control ambient acoustic noise;

a signal generator to generate an inverse anti-noise signal;

a first driver to drive the earpiece speaker based on the downlink audio signal and the anti-noise signal; and

a second driver to drive the HAC radiator based on the downlink audio signal and the inverse anti-noise signal.

15. The mobile phone of claim 14, further comprising:

a first combiner to digitally combine the downlink audio signal and the anti-noise signal; and

a second combiner to digitally combine the audio signal and the inverse anti-noise signal.

16. The mobile phone of claim 14, wherein the signal generator is to generate the inverse anti-noise signal by inverting the anti-noise signal.

17. The mobile phone of claim 14, wherein the inverse anti-noise signal is an out-of-phase version of the anti-noise signal.

18. The mobile phone of claim 14, further comprising:

a microphone to pick up the ambient acoustic noise for use by the ANC

19. The mobile phone of claim 14, wherein the HAC radiator is positioned next to the earpiece speaker within a housing of the mobile phone.