Systems and methods for on ear detection of headsets

Patent metadata

Field	Value
Publication number	US-11240578-B2
Application number	US-201916724034-A
Country	US
Kind code	B2
Filing date	Dec 20, 2019
Priority date	Dec 20, 2019
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

Described embodiments generally relate to a signal processing device for on ear detection for an earbud. The device comprises a first microphone input for receiving a microphone signal from a first microphone, the first microphone being configured to be positioned within an ear of a user when the earbud is being worn; a second microphone input for receiving a microphone signal from a second microphone, the second microphone being configured to be positioned outside the ear of the user when the earbud is being worn; a signal generator configured to generate a signal for acoustic playback from a speaker configured to be positioned within the earbud; and a processor. The processor is configured to receive at least one first microphone signal from each of the first microphone input and the second microphone input, and compare the first microphone signals to determine the on ear status of the earbud; determine that the on ear status of the earbud cannot be sufficiently determined, generate a signal for acoustic playback from the speaker, receive a second microphone signal from the first microphone input, and compare the second microphone signal to the generated signal to determine the on ear status of the earbud.

First claim

The invention claimed is:

1. A signal processing device for on ear detection for an earbud, the device comprising:
a first microphone input for receiving a microphone signal from a first microphone, the first microphone being configured to be positioned within an ear of a user when the earbud is being worn;
a second microphone input for receiving a microphone signal from a second microphone, the second microphone being configured to be positioned outside the ear of the user when the earbud is being worn;
a signal generator configured to generate a signal for acoustic playback from a speaker configured to be positioned within the earbud; and
a processor configured to:
receive at least one first microphone signal from each of the first microphone input and the second microphone input where the first microphone signals are generated while no audio is being played via the speaker, and compare the first microphone signals to determine an on ear status of the earbud, wherein the earbud is determined to be on ear if a parameter of the first microphone signal from the first microphone is lower than a parameter of the first microphone signal from the second microphone by a predetermined threshold; and
determine that the on ear status of the earbud cannot be sufficiently determined, generate the signal for acoustic playback from the speaker, receive a second microphone signal from the first microphone input, and compare the second microphone signal to the generated signal to determine the on ear status of the earbud.

2. The signal processing device of claim 1 , further comprising a proximity sensor, and wherein the processor is further configured to receive at least one sensor signal from the proximity sensor indicating that the earbud is in proximity to an object, and to perform the steps of receiving at least one first microphone signals and comparing the first microphone signals to determine the on ear status of the earbud in response to receiving the at least one sensor signal from the proximity sensor.

3. The signal processing device of claim 2 , wherein the proximity sensor is an infra-red sensor.

4. The signal processing device of claim 1 , wherein comparing the first microphone signals to determine the on ear status of the earbud comprises comparing a power level of the first microphone signals.

5. The signal processing device of claim 4 , wherein comparing the first microphone signals to determine the on ear status of the earbud further comprises determining that the earbud is on ear if the power of the first microphone signal received from the first microphone is lower than the first microphone signal received from the second microphone by a predetermined threshold.

6. The signal processing device of claim 4 , wherein comparing the first microphone signals to determine the on ear status of the earbud further comprises determining that the earbud is off ear if the power of the first microphone signal received from the first microphone is higher than the first microphone signal received from the second microphone by a predetermined threshold.

7. The signal processing device of claim 4 , wherein comparing the first microphone signals to determine the on ear status of the earbud further comprises determining that the on ear status of the earbud cannot be sufficiently determined if the power level of each of the first microphone signals is lower than a predetermined threshold.

8. The signal processing device of claim 1 , wherein comparing the second microphone signal to the generated signal to determine the on ear status of the earbud comprises determining whether the second microphone signal comprises resonance of the generated signal.

9. The signal processing device of claim 1 , wherein the generated signal is an audible probe signal.

10. The signal processing device of claim 9 , wherein the generated signal is of a frequency known to resonate in the human ear canal.

11. The signal processing device of claim 1 , wherein the processor is further configured to perform an audio processing function in response to the determined on ear status of the earbud.

12. A method of on ear detection for an earbud, the method comprising:
receiving a first microphone signal from a first microphone and a first microphone signal from a second microphone where the first microphone signals are generated while no audio is being played via a speaker configured to be positioned within the earbud, wherein the first microphone is configured to be positioned within an ear of a user when the earbud is being worn and the second microphone is configured to be positioned outside the ear of the user when the earbud is being worn;
comparing the first microphone signals to determine an on ear status of the earbud, wherein the earbud is determined to be on ear if a parameter of the first microphone signal from the first microphone is lower than a parameter of the first microphone signal from the second microphone by a predetermined threshold; and
determining that the on ear status of the earbud cannot be sufficiently determined, generating a signal for acoustic playback from the speaker, receiving a second microphone signal from the first microphone, and comparing the second microphone signal to the generated signal to determine the on ear status of the earbud.

13. The method of claim 12 , further comprising performing an audio processing function in response to the determined on ear status of the earbud.

14. A signal processing device for on ear detection of an earbud, the device comprising:
a first microphone input for receiving a microphone signal from a first microphone, the first microphone being configured to be positioned within an ear of a user when the earbud is being worn;
a second microphone input for receiving a microphone signal from a second microphone, the second microphone being configured to be positioned outside the ear of the user when the earbud is being worn;
a signal generator configured to generate a signal for acoustic playback from a speaker configured to be positioned within the earbud; and
a processor configured to:
generate the signal for acoustic playback from the speaker;
cause the signal to be played by the speaker;
receive at least one microphone signal from each of the first microphone input and the second microphone input, and compare the received microphone signals with the generated signal played by the speaker to detect resonance of the generated signal;
determine whether resonance is detected in the received microphone signals by comparing the received microphone signals with the generated signal played by the speaker, wherein resonance is determined to be detected when the resonance gain of the received microphone signals over the generated signal exceeds a predetermined threshold; and
determine an on ear status of the earbud;

wherein the earbud is determined to be on ear only if the resonance is detected in the signal from the first microphone input but is not detected in the signal from the second microphone input.

15. The signal processing device of claim 14 , wherein the generated signal is an audible probe signal.

16. The signal processing device of claim 15 , wherein the generated signal is of a frequency known to resonate in the human ear canal.

17. The signal processing device of claim 14 , wherein the processor is further configured to filter the received microphone signals with a bandpass filter prior to comparing the received microphone signals.

18. The signal processing device of claim 17 , wherein the bandpass filter is matched to

Assignees

• Cirrus Logic Int Semiconductor Ltd
• Cirrus Logic Inc

Inventors

• Steele Brenton

Classifications

• H04R2460/01

  Hearing devices using active noise cancellation · CPC title

• H04R1/1083

  Reduction of ambient noise (active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06) · CPC title

• H04R1/1041 Primary

  Mechanical or electronic switches, or control elements (switches in general H01H) · CPC title

• H04R29/006

  Microphone matching · CPC title

• H04R1/265

  of microphones · CPC title