Portable device comprising a directional system

Patent metadata

Field	Value
Publication number	US-11330366-B2
Application number	US-202016855232-A
Country	US
Kind code	B2
Filing date	Apr 22, 2020
Priority date	Apr 22, 2020
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

A sound capture device configured to be worn by a person and/or to be located on a surface is configured to pick up target sound from a target sound source s. The sound capture device comprises a) an input unit providing a multitude of electric input signals, each comprising a target signal component and a noise signal component; b) a directional noise reduction system comprising a beamformer unit coupled to said multitude of input signals and configured to provide an estimate of the target sound s. The beamformer unit comprises b1) target maintaining, reference beamformer providing a current reference signal; and b2) a target cancelling beamformer providing a current target cancelling sign. The directional noise reduction system is configured to operate in at least two modes in dependence of a mode control signal, 1) in a directional mode and 2) in a non-directional, omni-directional mode. The sound capture device further comprises c) antenna and transceiver circuitry for establishing an audio link to another device, and to transmit said estimate of the target sound s to said another device, and d) a mode controller for determining said mode control signal in dependence of said current reference signal and said current target cancelling signal. A method of operating a sound capture device is further disclosed.

First claim

The invention claimed is:

1. A sound capture device configured to be worn by a person and/or to be located on a surface, the sound capture device being configured to pick up target sound from a target sound source s, the sound capture device comprising
an input unit comprising a multitude of input transducers IT m , m=1, 2, . . . , M, M being larger than or equal to two, each input transducer being configured to pick up a sound from the environment of the sound capture device and to provide corresponding electric input signals, each electric input signal IN m , m=1, . . . , M, comprising a target signal component and a noise signal component;
a housing wherein said multitude of input transducers are located;
a directional noise reduction system for providing an estimate of the target sound s, the directional noise reduction system comprising a beamformer unit operationally coupled to said multitude of input transducers IT m , m=1, . . . , M, the beamformer unit comprising
target maintaining, reference beamformer configured to leave signal components from a fixed target direction un-attenuated or less attenuated relative to signal components from other directions, and providing a current reference signal; and
a target cancelling beamformer configured to attenuate signal components from said target direction, whereas signal components from other directions are attenuated less relative to signal components from said target direction, and providing a current target cancelling signal;

the directional noise reduction system being configured to operate in at least two modes in dependence of a mode control signal,
a directional mode wherein said estimate of the target sound s is based on target signal components from said fixed target direction, and
a non-directional, omni-directional mode, wherein said estimate of the target sound s is based on target signal components from all directions;

antenna and transceiver circuitry for establishing an audio link to another device, and wherein the sound capture device is configured to transmit said estimate of the target sound s to said another device; and
a mode controller for determining said mode control signal in dependence of said current reference signal and said current target cancelling signal.

2. A sound capture device according to claim 1 , wherein at least one of said input transducers is a microphone.

3. A sound capture device according to claim 1 comprising a filter bank.

4. A sound capture device according to claim 3 , wherein the magnitude, or otherwise processed versions, of the respective current reference signal and the current target cancelling signal are averaged across time to provide respective smoothed reference and target-cancelling measures.

5. A sound capture device according to claim 4 comprising a voice activity detector and wherein the sound capture device is configured to provide that the averaging only takes place, in time frames when the user's voice is detected by the voice activity detector.

6. A sound capture device according to claim 3 comprising a combination processor configured to compare said current reference signal and said current target cancelling signal, or processed versions thereof, in different frequency sub-bands, and to provide respective frequency sub-band comparison signals.

7. A sound capture device according to claim 3 comprising a decision controller configured to provide a resulting mode control signal indicative of an appropriate mode of operation of the directional noise reduction system in dependence of said frequency sub-band comparison signals.

8. A sound capture device according to claim 7 wherein said decision controller is configured to provide said resulting mode control signal in dependence of a weighted sum of individual sub-band comparison signals.

9. A sound capture device according to claim 7 wherein said directional noise reduction system is adapted to be in a directional mode when said mode control signal indicates a relatively large difference over frequency between said current reference signal and said current target cancelling signal, or processed versions thereof, and to be in an omni-directional mode when said mode control signal indicates a relatively small difference over frequency between said current reference signal and said current target cancelling signal, or processed versions thereof.

10. A sound capture device according to claim 1 being constituted by or comprising a microphone device.

11. A hearing system comprising a sound capture device according to claim 1 and the another device, wherein said sound capture device and said another device are configured to establish a communication link between them allowing the exchange of data, including audio data between them or from the sound capture device to the another device.

12. A hearing system according to claim 11 wherein the another device is a hearing device.

13. A hearing system according to claim 12 wherein said hearing device is constituted by or comprises an air-conduction type hearing aid, a bone-conduction type hearing aid, a cochlear implant type hearing aid, or a combination thereof.

14. A hearing system according to claim 11 adapted to provide that said sound capture device transmits said estimate of the target sound s to the another device.

15. Use of a sound capture device as claimed in claim 1 .

16. A sound capture device according to claim 1 wherein the housing comprises a preferred direction coinciding with said fixed target direction.

17. A method of operating a sound capture device configured to be worn by a person and/or to be located on a surface, the sound capture device being configured to pick up target sound from a target sound source s, the method comprising
providing a multitude M of electric input signals, each electric input signal IN m , m=1, . . . , M, comprising a target signal component and a noise signal component;
providing an estimate of the target sound s,
providing a target maintaining, reference beamformer configured to attenuate signal components from other directions than a fixed target direction, whereas signal components from the fixed target direction are left un-attenuated or are attenuated less relative to signal components from said other directions, and providing a reference signal in dependence of said multitude M of electric input signals; and
providing a target cancelling beamformer configured to attenuate signal components from said target direction, whereas signal components from other directions are attenuated less relative to signal components from said target direction, and providing a target cancelling signal in dependence of said multitude M of electric input signals;
providing at least two modes in dependence of a mode control signal,
a directional mode wherein said estimate of the target sound s is based on target signal components from said fixed target direction, and
a non-directional, omni-directional mode, wherein said estimate of the target sound s is based on target signal components from all directions;

establishing an audio link to another device, and
transmitting said estimate of the target sound s to said another device,
determining said mode control signal in dependence of said reference signal and said target cancelling signal.

18. A data processing system comprising a processor and program code means for causing the processor to perform the steps of the method of claim 17 .

19. A non-transitory computer readable medium on which is stored a computer program comprising inst

Assignees

• Oticon As

Inventors

• Pedersen Michael Syskind
• Scheel Carsten
• Bergmann Martin
• Bay Henrik
• Pedersen Morten
• Krogsgaard Bent
• Mikkelsen Jacob
• Gram Stefan
• De Haan Jan M
• Bertelsen Andreas Thelander

Classifications

• H04R25/507

  implemented by neural network or fuzzy logic · CPC title

• G10L2021/02166

  Microphone arrays; Beamforming · CPC title

• H04R1/406 Primary

  microphones · CPC title

• H04R25/407 Primary

  Circuits for combining signals of a plurality of transducers · CPC title

• H04R25/00 Primary

  Electric hearing aids · CPC title