Systems and methods of detecting speech activity of headphone user

• US 10,366,708 B2
• Filed: 03/20/2017
• Issued: 07/30/2019
• Est. Priority Date: 03/20/2017
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Yeo, Xiang-Ern, Ergezer, Mehmet, Ganeshkumar, Alaganandan
• Primary Examiner(s): Yu, Norman
• Application Number:
  US15/463,259
• Publication Number:
  US 20180268845A1
• Time in Patent Office: 862 Days
• Field of Search: 381 56, 381 74, 381110, 381122, 381 716, 704275, 704233, 704200, 704214
• CPC Class Codes: G10L 2025/783 based on threshold decision
• CPC Class Codes: G10L 25/21 the extracted parameters being power information
• CPC Class Codes: G10L 25/51 for comparison or discrimination
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10
• CPC Class Codes: G10L 25/93 Discriminating between voiced and unvoiced parts of speech signals G10L25/90 takes precedence
• CPC Class Codes: H04R 1/1008 Earpieces of the supra-aural or circum-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 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A headphone system is provided that includes a left and right earpiece having a left and right microphone, respectively, to receive left and right acoustic signals and provide left and right signals for processing. The left and right signals are added to provide a principal signal, and the left and right signals are subtracted to provide a reference signal. A detection circuit compares the principal signal to the reference signal and selectively indicates whether a user is speaking.

Claims

1. A headphone system, comprising:

a left earpiece;

a right earpiece;

a left microphone coupled to the left earpiece to receive a left acoustic signal and to provide a left signal derived from the left acoustic signal;

a right microphone coupled to the right earpiece to receive a right acoustic signal and to provide a right signal derived from the right acoustic signal; and

a detection circuit coupled to the left microphone and the right microphone, the detection circuit configured to process both a principal signal and a reference signal through a smoothing algorithm, the principal signal derived from a sum of the left signal and the right signal and the reference signal derived from a difference between the left signal and the right signal, the smoothing algorithm configured to calculate a principal power signal from a decaying weighted average of power of the principal signal over time, to calculate a reference power signal from a decaying weighted average of power of the reference signal over time, and to selectively indicate that the user is speaking based at least in part upon a comparison between the principle power signal and the reference power signal.

2. The headphone system of claim 1 wherein the detection circuit is configured to indicate the user is speaking when the principal power signal exceeds the reference power signal by a threshold.

3. The headphone system of claim 1 wherein the principal signal and the reference signal are each band filtered.

4. The headphone system of claim 1 wherein at least one of the left microphone and the right microphone comprises a plurality of microphones and the respective left signal or right signal is derived from the plurality of microphones, at least in part, as a combination of outputs from one or more of the plurality of microphones.

5. The headphone system of claim 1 further comprising:

a rear microphone coupled to either earpiece and positioned to receive a rear acoustic signal, the rear acoustic signal being toward the rear of the user'"'"'s head relative to either or both of the left acoustic signal and the right acoustic signal;

the detection circuit further configured to compare a rear signal derived from the rear microphone to at least one of the left signal and the right signal to generate a rear comparison, and to selectively indicate that the user is speaking further based upon the rear comparison.

6. The headphone system of claim 5 wherein the detection circuit indicates the user is speaking when the principal power signal exceeds the reference power signal by a first threshold and the at least one of the left signal and the right signal exceeds the rear signal by a second threshold.

7. A method of determining that a headphone user is speaking, the method comprising:

receiving a first signal derived from a first microphone configured to receive acoustic signals near a left side of the user;

receiving a second signal derived from a second microphone configured to receive acoustic signals near a right side of the user;

providing a principal signal derived from a sum of the first signal and the second signal;

providing a reference signal derived from a difference between the first signal and the second signal;

processing the principal signal through a smoothing algorithm configured to calculate a principal power signal from a decaying weighted average of power of the principal signal over time;

processing the reference signal through the smoothing algorithm to calculate a reference power signal from a decaying weighted average of power of the reference signal over time;

comparing the principal power signal to the reference power signal; and

selectively indicating that a user is speaking based at least in part upon the comparison.

8. The method of claim 7 wherein comparing the principal signal to the reference power signal comprises comparing whether the principal power signal exceeds the reference signal by a threshold.

9. The method of claim 7 further comprising filtering at least one of the first signal, the second signal, the principal signal, and the reference signal.

10. The method of claim 7 wherein the first signal is derived from a plurality of first microphones at least in part as a combination of outputs from one or more of the plurality of first microphones.

11. The method of claim 7 further comprising:

receiving a third signal derived from a third microphone;

comparing the third signal to at least one of the first signal and the second signal to generate a second comparison; and

selectively indicating that the user is speaking based at least in part upon the second comparison.