Remote microphone for a hearing aid
A remote microphone device for a hearing aid system comprises a multitude of microphones providing a corresponding multitude of electric input signals; a digital signal processor for providing a processed signal in dependence of said multitude of electric input signals. The processor comprises a noise reduction system comprising at least one beamformer for providing a spatially filtered signal. The remote microphone device further comprises a wireless communication interface comprising antenna and transceiver circuitry allowing the remote microphone device to transmit said processed signal comprising said spatially filtered signal or a further processed version thereof to said hearing aid system; a rechargeable battery; a casing having a planar structure with a form and size as a standard credit card; and a user interface configured to allow the user to control functionality of the remote microphone device. The invention may e.g. be used in hearing aid systems or headsets.
1. A remote microphone device for a hearing aid system, the remote microphone device comprising:
a multitude of microphones, each providing an electric input signal representing sound in the environment of the microphone device, thereby providing a corresponding multitude of electric input signals;
a digital signal processor for providing a processed signal in dependence of said multitude of electric input signals, the processor comprising a noise reduction system comprising:
at least one beamformer for providing a spatially filtered signal in dependence of
said multitude of electric input signals, or signals originating therefrom; and
beamformer filter coefficients, said beamformer filter coefficients being determined in dependence of a steering vector comprising as elements respective acoustic transfer functions from a target signal to each of said multitude of input transducers or acoustic transfer functions from a reference input transducer among said multitude of input transducers to each of the remaining input transducers;
a wireless communication interface comprising antenna and transceiver circuitry allowing the remote microphone device to transmit said processed signal comprising said spatially filtered signal or a further processed version thereof to said hearing aid system;
a rechargeable battery;
wherein said remote microphone device comprises a casing having a planar structure with a form and size as a standard credit card; and comprises a user interface configured to allow a user to control functionality of the remote microphone device in dependence of one or more activation elements,
wherein at least some of said multitude of microphones are located in corners of said standard credit card form.
2. The remote microphone device according to claim 1 wherein said one or more activation elements comprises one or more buttons.
3. The remote microphone device according to claim 1 wherein said user interface comprises a voice control interface allowing the user to control the functionality of the remote microphone device by spoken commands.
4. The remote microphone device according to claim 1 wherein said user interface comprises one or more indicators for providing feedback to the user about a current status of the remote microphone device.
5. The remote microphone device according to claim 1 comprising a sensor allowing to detect an orientation of the remote microphone device.
6. The remote microphone device according to claim 5 configured to enter an omni-directional mode of operation in case its planar orientation is perpendicular to the force of gravity of the earth.
7. The remote microphone device according to claim 1 configured to determine which of the two planar outer surfaces (x,y) of the casing of the device is presently facing upwards when the device is resting on a planar, horizontal, carrier.
8. The remote microphone device according to claim 1 configured to exchange information with a further remote device.
9. A remote microphone device for a hearing aid system, the remote microphone device comprising:
a multitude of microphones, each providing an electric input signal representing sound in the environment of the microphone device, thereby providing a corresponding multitude of electric input signals;
a digital signal processor for providing a processed signal in dependence of said multitude of electric input signals, the processor comprising a noise reduction system comprising:
at least one beamformer for providing a spatially filtered signal in dependence of
said multitude of electric input signals, or signals originating therefrom; and
beamformer filter coefficients, said beamformer filter coefficients being determined in dependence of a steering vector comprising as elements respective acoustic transfer functions from a target signal to each of said multitude of input transducers or acoustic transfer functions from a reference input transducer among said multitude of input transducers to each of the remaining input transducers;
a wireless communication interface comprising antenna and transceiver circuitry allowing the remote microphone device to transmit said processed signal comprising said spatially filtered signal or a further processed version thereof to said hearing aid system;
a rechargeable battery;
wherein said remote microphone device comprises a casing having a planar structure with a form and size as a standard credit card; and comprises a user interface configured to allow a user to control functionality of the remote microphone device in dependence of one or more activation elements,
wherein each of the multitude of microphones is mounted in a suspension comprising a flexible material in a cavity or opening in the credit card size casing of the remote microphone device.
10. The remote microphone device according to claim 1 wherein a microphone inlet of one of said multitude of microphones is covered with a filter or membrane.
11. The remote microphone device according to claim 10 comprising a membrane for providing an acoustically transparent closure.
12. The remote microphone device according to claim 10 wherein the membrane is placed in the casing on a substrate where the one of said multitude of microphones is located.
13. The remote microphone device according to claim 12 wherein the microphones are mounted on the substrate to have a microphone inlet opening facing a first surface of the substrate, and wherein the substrate comprises an opening concentrical with the microphone inlet opening, and wherein membrane is placed on the opposite, second surface of the substrate covering said opening in the substrate.
14. The remote microphone device according to claim 1 comprising a charging coil configured to wirelessly receive charging energy from an external charging device allowing said charging coil to charge said rechargeable battery.
15. A remote microphone device for a hearing aid system, the remote microphone device comprising:
a multitude of microphones, each providing an electric input signal representing sound in the environment of the microphone device, thereby providing a corresponding multitude of electric input signals;
a digital signal processor for providing a processed signal in dependence of said multitude of electric input signals, the processor comprising a noise reduction system comprising:
at least one beamformer for providing a spatially filtered signal in dependence of
said multitude of electric input signals, or signals originating therefrom; and
beamformer filter coefficients, said beamformer filter coefficients being determined in dependence of a steering vector comprising as elements respective acoustic transfer functions from a target signal to each of said multitude of input transducers or acoustic transfer functions from a reference input transducer among said multitude of input transducers to each of the remaining input transducers;
a wireless communication interface comprising antenna and transceiver circuitry allowing the remote microphone device to transmit said processed signal comprising said spatially filtered signal or a further processed version thereof to said hearing aid system;
a rechargeable battery;
wherein said remote microphone device comprises a casing having a planar structure with a form and size as a standard credit card; and comprises a user interface configured to allow a user to control functionality of the remote microphone device in dependence of one or more activation elements,
wherein said remote microphone device further comprises a charging coil configured to wirelessly receive charging energy from an external charging device allowing said charging coil to charge said rechargeable battery, and
wherein the charging coil is located on the battery, separated from a battery housing by an electromagnetically shielding layer.
16. The remote microphone device according to claim 1 wherein said casing has a dimension of less than or equal to 2 mm in a direction perpendicular to its planar surfaces.
17. A hearing aid system comprising at least one hearing aid and a remote microphone device according to claim 1 .
18. The hearing aid system according to claim 17 , adapted to establish a communication link between the remote microphone device and an auxiliary device to provide that data can be exchanged or forwarded from one to the other.
19. The hearing aid system according to claim 18 comprising a user interface—implemented in the auxiliary device—for controlling the hearing aid system.