Dynamic on ear headset detection

• US 10,264,345 B1
• Filed: 09/10/2018
• Issued: 04/16/2019
• Est. Priority Date: 10/10/2017
• Status: Active Grant

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Sapozhnykov, Vitaliy, Harvey, Thomas Ivan, Erfaniansaeedi, Nafiseh, Luke, Robert
• Primary Examiner(s): Anwah, Olisa
• Application Number:
  US16/125,950
• Publication Number:
  US 20190110120A1
• Time in Patent Office: 218 Days
• CPC Class Codes: G10K 11/17815 between the reference signals and the error signals, i.e. primary path
• CPC Class Codes: G10K 11/17817 between the output signals and the error signals, i.e. secondary path
• CPC Class Codes: G10K 11/17823 Reference signals, e.g. ambient acoustic environment
• CPC Class Codes: G10K 11/17825 Error signals
• CPC Class Codes: G10K 2210/1081 Earphones, e.g. for telephones, ear protectors or headsets
• CPC Class Codes: G10K 2210/30351 Identification of the environment for applying appropriate model characteristics
• CPC Class Codes: G10K 2210/3043 Phase locked loops [PLL]
• CPC Class Codes: G10K 2210/3046 Multiple acoustic inputs, multiple acoustic outputs
• CPC Class Codes: G10K 2210/503 Diagnostics; Stability; Alarms; Failsafe
• CPC Class Codes: H04R 1/1008 Earpieces of the supra-aural or circum-aural type
• CPC Class Codes: H04R 1/1016 Earpieces of the intra-aural type
• CPC Class Codes: H04R 1/1041 Mechanical or electronic switches, or control elements switches in general H01H
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2201/107 Monophonic and stereophonic headphones with microphone for two-way hands free communication
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 2460/01 Hearing devices using active noise cancellation
• CPC Class Codes: H04R 2460/03 Aspects of the reduction of energy consumption in hearing devices
• CPC Class Codes: H04R 2460/15 Determination of the acoustic seal of ear moulds or ear tips of hearing devices
• CPC Class Codes: H04R 29/001 for loudspeakers H04R29/007 takes precedence
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A method and device for detecting whether a headset is on ear. Microphone signals from a plurality of microphones are used to derive a plurality of signal feature measures, which are normalized to a common reference scale. The signal feature measures are weighted based upon detected signal conditions in the microphone signals. The normalized and variably weighted signal feature measures are then combined to produce an output indication of whether a headset is on ear.

Claims

1. A signal processing device for on ear detection for a headset, the device comprising:

a plurality of inputs for receiving respective microphone signals from a plurality of microphones; and

a processor configured to derive from the microphone signals a plurality of signal feature measures, the processor further configured to normalise the signal feature measures by applying a non-linear mapping of each signal feature measure to a unitless reference scale;

the processor further configured to variably weight the signal feature measures in response to detected signal conditions in the microphone signals;

the processor further configured to combine the variably weighted normalized signal feature measures to produce an output indication of whether a headset is on ear.

2. The signal processing device of claim 1 wherein the detected signal conditions comprise signal presence indicators respectively indicating whether a signal is present on the microphone signals.

3. The signal processing device of claim 1 wherein the plurality of signal feature measures comprises a signal feature reflecting passive loss, being the attenuation in an external sound level or a signal feature reflecting occlusion gain, being the increase in sound level which occurs when the earbud is on ear.

4. The signal processing device of claim 1 wherein the processor is configured to create an inaudible acoustic probe signal for playback.

5. The signal processing device of any one of claim 1, further comprising a control module which is configured to select a weighting to be applied to the signal feature measures based on the detected signal conditions in the microphone signals.

6. The signal processing device of any one of claim 1, further comprising a memory storage storing predefined signal feature weightings to be applied to the signal features measures, each predefined signal feature weighting corresponding to a respective detected signal condition.

7. The signal processing device of claim 1 further comprising a linear combiner for multiplying the signal feature measures by respective variable weights.

8. The signal processing device of claim 1 wherein the processor is configured to alter at least one signal processing function in response to a determination that the headset is not on ear.

9. A method for on ear detection for a headset, the method comprising:

receiving respective microphone signals from a plurality of microphones;

deriving from the microphone signals a plurality of signal feature measures;

normalising the signal feature measures by applying a non-linear mapping of each signal feature measure to a unitless reference scale;

variably weighting the signal feature measures in response to detected signal conditions in the microphone signals; and

combining the variably weighted normalized signal feature measures to produce an output indication of whether a headset is on ear.

10. The method of claim 9 wherein the detected signal conditions comprise signal presence indicators respectively indicating whether a signal is present on the microphone signals.

11. The method of claim 9 wherein the plurality of signal feature measures comprises a signal feature reflecting passive loss, being the attenuation in an external sound level or a signal feature reflecting occlusion gain, being the increase in sound level which occurs when the earbud is on ear.

12. The method of claim 9 further comprising creating an inaudible acoustic probe signal for playback.

13. The method of claim 9 further comprising selecting a weighting to be applied to the signal feature measures based on the detected signal conditions in the microphone signals.

14. The method of claim 9 further comprising retrieving signal feature weightings to be applied to the signal features measures from a memory storage storing predefined signal feature weightings each corresponding to a respective detected signal condition.

15. The method of claim 9 wherein the combining comprises summing the products of the signal feature measures with the respective variable weights to produce a soft decision whether a headset is on ear.

16. A non-transitory computer readable medium for on ear detection for a headset, comprising instructions which, when executed by one or more processors, causes performance of the following:

receiving respective microphone signals from a plurality of microphones;

deriving from the microphone signals a plurality of signal feature measures;

normalising the signal feature measures by applying a non-linear mapping of each signal feature measure to a unitless reference scale;

variably weighting the signal feature measures in response to detected environmental conditions in the microphone signals; and

combining the variably weighted normalized signal feature measures to produce an output indication of whether a headset is on ear.

17. A system for on ear detection for a headset, the system comprising a processor and a memory, the memory containing instructions executable by the processor and wherein the system is operative to:

receive respective microphone signals from a plurality of microphones;

derive from the microphone signals a plurality of signal feature measures;

normalise the signal feature measures by applying a non-linear mapping of each signal feature measure to a unitless reference scale;

variably weight the signal feature measures in response to detected signal conditions in the microphone signals; and

combine the variably weighted normalized signal feature measures to produce an output indication of whether a headset is on ear.

18. The system of claim 17, wherein the system is a headset or an earbud or a smartphone.

19. A signal processing device for on ear detection for a headset, the device comprising:

a plurality of inputs for receiving respective microphone signals from a plurality of microphones; and

a processor configured to derive from the microphone signals a plurality of signal feature measures, the processor further configured to normalise the signal feature measures;

the processor further configured to variably weight the signal feature measures in response to detected signal conditions in the microphone signals;

the processor further configured to combine the variably weighted normalised signal feature measures to produce an output indication of whether a headset is on ear, wherein the processor is configured to select a weighting to be applied to the signal feature measures based on the detected signal conditions in the microphone signals.

20. A signal processing device for on ear detection for a headset, the device comprising:

a plurality of inputs for receiving respective microphone signals from a plurality of microphones;

a processor configured to derive from the microphone signals a plurality of signal feature measures, the processor further configured to normalise the signal feature measures;

the processor further configured to variably weight the signal feature measures in response to detected signal conditions in the microphone signals;

the processor further configured to combine the variably weighted normalised signal feature measures to produce an output indication of whether a headset is on ear; and

a memory storage storing predefined signal feature weightings to be applied to the signal features measures, each predefined signal feature weighting corresponding to a respective detected signal condition.

21. A signal processing device for on ear detection for a headset, the device comprising:

a plurality of inputs for receiving respective microphone signals from a plurality of microphones;

a processor configured to derive from the microphone signals a plurality of signal feature measures, the processor further configured to normalise the signal feature measures;

the processor further configured to variably weight the signal feature measures in response to detected signal conditions in the microphone signals;

the processor further configured to combine the variably weighted normalised signal feature measures to produce an output indication of whether a headset is on ear; and

a linear combiner for multiplying the signal feature measures by respective variable weights.