User voice activity detection methods, devices, assemblies, and components

Patent metadata

Field	Value
Publication number	US-10564925-B2
Application number	US-201715711793-A
Country	US
Kind code	B2
Filing date	Sep 21, 2017
Priority date	Feb 7, 2017
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

Many headsets include automatic noise cancellation (ANC) which dramatically reduces perceived background noise and improves user listening experience. Unfortunately, the voice microphones in these devices often capture ambient noise that the headsets output during phone calls or other communication sessions to other users. In response, many headsets and communication devices provide manual muting circuitry, but users frequently forget to turn the muting on and/or off, creating further problems as they communicate. To address this, the present inventors devised, among other things, an exemplary headset that detects the absence or presence of user speech, automatically muting and unmuting the voice microphone without user intervention. Some embodiments leverage relationships between feedback and feedforward signals in ANC circuitry to detect user speech, avoiding the addition of extra hardware to the headset. Other embodiments also leverage the speech detection function to activate and deactivate keyword detectors, and/or sidetone circuits, thus extending battery.

First claim

What is claimed is:

1. A communication assembly comprising:
an incoming audio signal node configured for connection to a communication device that provides an incoming audio signal;
signal processing circuitry configured to output a voice activity detection signal indicative of a determined absence or presence of user speech, the signal processing circuitry configured to determine absence or presence of user speech based on a first signal ϕ, a second signal θ, and a third signal, with the ϕ and θ signals derived from two or more transducers responsive to at least ambient noise a, user speech s, and the third signal, with the ϕ and θ signals satisfying a constraint

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T sθ representing a transfer function from user speech s to signal θ, T aθ representing a transfer function from ambient noise a to signal θ, T sΦ representing a transfer function from user speech s to signal ϕ, T aϕ representing a transfer function from ambient noise a to signal ϕ, and the third signal based at least in part on the incoming audio signal or at least one audio notification signal.

2. The communication assembly of claim 1 , wherein the two or more transducers include first and second microphones, with the first microphone positioned with substantially greater acoustic coupling to a user vocal region than the second microphone.

3. The communication assembly of claim 2 , wherein the first microphone is positioned to receive more acoustic energy from the user vocal region via a bone conduction path than the second microphone.

4. The communication assembly of claim 1 , further comprising an automatic muting module configured to attenuate a voice microphone output signal in response to the voice activity detection signal indicating a determined absence of user speech and to de-attenuate the voice microphone output signal in response to the voice activity detection signal indicating presence of user speech.

5. The communication assembly of claim 1 , wherein the automatic muting module is configured to mute or attenuate the voice microphone output signal a predetermined amount of time after receipt of the voice activity detection signal.

6. The communication assembly of claim 1 , further comprising a keyword recognition module configured to recognize one or more keywords within user speech signals derived from a voice microphone output signal and responsive to the voice activity detection signal indicating a determined absence of user speech to enter a shutdown or sleep state to conserve power or memory.

7. The communication assembly of claim 1 , further comprising a side tone module responsive to user speech to provide a side tone signal to a loud speaker within a headset earpiece and responsive to the voice activity detection signal indicating a determined absence of user speech to enter a shutdown or sleep state to conserve power or memory.

8. The communication assembly of claim 1 , further comprising a noise reduction module responsive to the voice activity detection signal indicating a determined presence of user speech to reduce noise in a first way and responsive to the voice activity detection signal indicating a determined absence of user speech to reduce noise in a second way.

9. The communication assembly of claim 1 , further comprising at least one speech-dependent module configured for operation in a manner dependent on speech content of a voice microphone output signal and responsive to the voice activity detection signal indicating a determined absence of user speech to enter a power and/or memory conservation mode.

10. The communication assembly of claim 1 , further comprising a first node configured for connection to a loud speaker associated with a headset earpiece, a second node configured for connection to a feedforward ambient microphone associated with the headset earpiece, and a third node configured for connection to a feedback error microphone associated with headset earpiece, the signal processing circuitry coupled to the first, second and third nodes, and configured to provide an anti-noise signal to the loud speaker in response to signals originating from the feedforward ambient microphone and the feedback error microphone, and the ϕ and θ signals derived from signals originating from the feedforward ambient microphone and the feedback error microphone.

11. The communication assembly of claim 10 , wherein the signal processing circuitry is further configured to indicate absence of the user speech when the first and second transducers are placed on a standard head and torso simulator (HATS) that is outputting a speech signal in the range.

12. The communication assembly of claim 10 , wherein the headset earpiece in an in-the-ear earpiece having an ear-canal portion containing the feedback error microphone.

13. A method of operating a communication assembly having a voice microphone output signal and a set of two or more transducers, the method comprising:
determining whether a user of the communication assembly is speaking based on the output of the two or more transducers by deriving a first signal ϕ and a second signal θ, with the ϕ and θ signals derived from the two or more transducers transducing an ambient noise signal a, user speech signal s, and a third signal, with the ϕ and θ signals satisfying a constraint

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Assignees

• Avnera Corp

Inventors

• An Jiajin
• Wurtz Michael Jon
• Wurtz David
• Khaira Manpreet
• Kumar Amit
• O'Connor Shawn
• Rathoud Shankar
• Scanlan James
• Sorensen Eric

Classifications

• G10K11/1781

  characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions · CPC title

• G06F3/165 Primary

  Management of the audio stream, e.g. setting of volume, audio stream path · CPC title

• G10K2210/1081

  Earphones, e.g. for telephones, ear protectors or headsets · CPC title

• H04R5/033

  Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)} · CPC title

• H04R2201/107

  Monophonic and stereophonic headphones with microphone for two-way hands free communication · CPC title