Hearing assistance system and method

• US 9,210,519 B2
• Filed: 04/22/2010
• Issued: 12/08/2015
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Sonova AG (Sonova Holding AG)
• Original Assignee: Sonova AG (Sonova Holding AG)
• Inventors: Callias, Francois, El-Hoiydi, Amre, Richard, Claude
• Primary Examiner(s): Goins, Davetta W
• Assistant Examiner(s): Ojo, Oyesola C
• Application Number:
  US13/642,708
• Publication Number:
  US 20130129126A1
• Time in Patent Office: 2,056 Days
• Field of Search: 381/315, 381/94.5, 381/94.6
• US Class Current: 1/1
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H04R 2225/33 Aspects relating to adaptation of the battery voltage, e.g. its regulation, increase or decrease
• CPC Class Codes: H04R 2225/55 Communication between hearing aids and external devices via a network for data exchange
• CPC Class Codes: H04R 2227/003 Digital PA systems using, e.g. LAN or internet
• CPC Class Codes: H04R 2460/03 Aspects of the reduction of energy consumption in hearing devices
• CPC Class Codes: H04R 25/305 Self-monitoring or self-testing
• CPC Class Codes: H04R 25/407 Circuits for combining signals of a plurality of transducers
• CPC Class Codes: H04R 25/453 electronically
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils
• CPC Class Codes: H04R 27/02 Amplifying systems for the deaf

Abstract

A system for providing hearing assistance to at least one user, having at least one audio signal source; a transmission unit with a digital transmitter for wirelessly transmitting audio signals as data packets to a frame structure from the audio signal source; at least one ear-worn receiver unit for receiving the transmitted audio signals and a hearing stimulating mechanism, the receiver unit having a digital transceiver adapted to listen, and optionally transmit, during part of each frame and to sleep during the remainder of the frame; wherein the receiver unit has a capacitor for supplying current to the transceiver during listening or transmission operation, and a controlled current source including a control unit for controlling current flowing to the transceiver and the capacitor a manner preventing changes in the current flowing to the transceiver and the capacitor caused by the transceiver switching between sleeping and listening/transmission operation and vice versa.

Claims

1. A system for providing hearing assistance to at least one user, comprising:

at least one audio signal source for providing audio signals;

a transmission unit comprising a digital transmitter for applying a digital modulation scheme in order to transmit the audio signals as data packets according to a frame structure from the audio signal source via a wireless digital audio link;

at least one receiver unit for reception of audio signals from the transmission unit via the digital audio link, wherein the receiver unit is connected to or integrated within an ear- worn device comprising a power source and means for stimulating a hearing of the user(s) according to audio signals supplied from the receiver unit, wherein the receiver unit comprises a digital transceiver which is powered by a power source of the ear-worn device and which is adapted to at least listen during part of each frame and to sleep during the remainder of the frame;

wherein the receiver unit comprises a capacitor connected in parallel to the transceiver for supplying the transceiver during listening or transmission operation with current and for being recharged by the power source of the ear-worn device and a controlled current source including a control unit for controlling the current flowing from the power source to the transceiver and the capacitor in a manner so as to prevent changes in the current flowing from the power source to the transceiver and the capacitor caused by the transceiver switching between sleeping and listening/transmission operation and vice versa, respectively, which are expected to add an audible noise signal to the audio signals supplied to the stimulation means, wherein the controlled current source includes a voltage multiplier for increasing a voltage provided by the power source, and wherein the voltage multiplier is a step-up DC/DC converter having its input connected to the power source and delivering an output voltage to the capacitor and the transceiver having a value set between a lower limit and an upper limit, and wherein the controlled current source is adapted to adjust the current flowing from the power source to the transceiver and the capacitor to a constant target current value selected according to an estimated quality of the audio link or according to the estimated average current consumption of the transceiver.

2. The system of claim 1, wherein the controlled current source and the capacitor are designed to keep the current flowing from the power source to the transceiver within +0.1% at a target value.

3. The system of claim 1, wherein the controlled current source is adapted to adjust, in case of a deterioration of the estimated quality of the audio link, the current to a new target current value corresponding to the changed quality of the audio link with a time constant of at least 0.05 s.

4. 4 The system of claim 1, wherein the controlled current source is adapted to adjust, in case of an improvement of the estimated quality of the audio link, the current to a new target current value corresponding to the changed quality of the audio link with a time constant of from 0.5 to 1 s.

5. The system of claim 1, wherein the controlled current source is adapted to select the target current value at the estimated average current to be consumed by the transceiver plus a safety overhead of up to 20% to account for transient changes in link quality.

6. The system of claim 1, wherein the controlled current source is adapted to an estimate of the link quality from an output signal of the transceiver indicative of at least one of a packet level error rate and a bit level error rate of the received audio signals.

7. The system of claim 1, wherein the controlled current source is adapted to monitor a voltage across the transceiver in a manner so as to keep it below a given threshold.

8. The system of claim 7, wherein the receiver unit is adapted to cause dummy discharge of the capacitor to keep the voltage across the transceiver below the given threshold.

9. The system of claim 8, wherein a shunt regulator connected in parallel to the capacitor is provided to cause dummy discharge of the capacitor to keep the voltage across the transceiver below the given threshold.

10. The system of claim 1, wherein the receiver unit comprises a voltage multiplier for increasing the voltage provided by the power source and for supplying the increased voltage to the controlled current source.

11. The system of claim 1, wherein the ear-worn device is a hearing aid.

12. The system of claim 11, wherein the receiver unit is connected to the hearing aid via a three-pin connector, including an audio signal pin, a power supply pin and a common ground pin.

13. The system of claim 1, wherein the transceiver is adapted to listen only during less than 10% of each frame.

14. The system of claim 1, wherein the step-up DC/DC converter is adapted to keep its input current drawn from the power source independent from its output voltage.

15. The system of claim 14, wherein the DC/DC converter is a bridged boost converter.

16. The system of claim 15, wherein the DC/DC converter comprises a coil for supplying the current from the power source through the coil to the capacitor and a plurality of switches, with the coil forming part of the bridge.

17. The system of claim 16, wherein the DC/DC converter is adapted to control the switches in a manner so as to operate in a cyclic discontinuous mode, wherein for a first time interval of each cycle the current through the coil is zero, wherein for a second time interval of each cycle current is drawn from the power source for energizing the coil, with the capacitor being disconnected from the coil, and wherein for a third time interval the capacitor is supplied with current from the coil, with the power source being disconnected from the coil.

18. The system of claim 17, wherein the DC/DC converter is adapted to select the second time interval independent from the converter output voltage.

19. The system of claim 17, wherein the DC/DC converter is adapted to control the switches according a power source voltage, a capacitor voltage and a voltage at the coil.

20. The system of claim 17, wherein the DC/DC converter is adapted to change a duty cycle of the coil as a function of a power source voltage and a capacitor voltage in order to keep the voltage across the transceiver below said given threshold.

21. The system of claim 17, wherein a duty cycle is provided having fundamental frequency of at least 16 kHz.

22. The system of claim 17, wherein the DC/DC converter comprises a fractional N-divider realized by a multi-modulus divider driven by a delta-sigma-modulator for changing a duty cycle of the coil.

23. The system of claim 18, wherein the controlled current source comprises also a step-down DC/DC converter having its input connected to the power source and delivering an output voltage for supplying a digital circuitry lower than a power source voltage, wherein a second capacitor is connected in parallel to the digital circuitry.

24. The system of claim 23, wherein the step-down DC/DC converter is adapted to share the coil of the step-up DC/DC converter.

25. The system of claim 24, wherein the step-down DC/DC converter is adpted to use the coil of the step-up DC/DC converter during the times when the coil is not used by the step-up DC/DC converter.

26. The system of claim 1, wherein the transmission unit is adapted to transmit each data packet in a separate slot of a TDMA frame, wherein each audio data packet comprises a start frame delimiter, audio data and a frame check sequence, and wherein the digital transceiver of the receiver unit(s) is adapted to verify each received data packet by using the frame check sequence and to use the audio data of the first verified version of each data packet as the signal to be supplied to the stimulation means, while not using the audio data of other versions.

27. The system of claim 26, wherein the transceiver is adapted to sleep at least during times when no data packets are to be expected.

28. The system of claim 1, wherein the audio signal source is a microphone arrangement integrated into or connected to the transmission unit for capturing a speaker'"'"'s voice.

29. The system of claim 1, wherein the digital transceiver is adapted to listen and transmits during part of each frame and to sleep during the remainder of the frame.

30. A method for providing hearing assistance to at least one user, comprising:

providing audio signals from at least one audio signal source to a transmission unit comprising a digital transmitter for applying a digital modulation scheme;

transmitting audio signals as data packets according to a frame structure via a digital wireless audio link from the transmission unit to at least one receiver unit connected to or integrated within an ear-worn device and comprising a digital transceiver, the ear-worn device comprising a power source which is used for powering the digital transceiver, wherein the digital transceiver at least listens during part of each frame and sleeps during a remainder of the frame;

stimulating, by using the ear-worn device, the hearing of the user(s) according to audio signals supplied from the receiver unit;

wherein the transceiver during listening or transmission operation is supplied with current by a capacitor connected in parallel to the transceiver, wherein the capacitor is recharged by the power source of the ear-worn device, and wherein the current flowing from the power source to the transceiver and the capacitor is controlled by a controlled current source in a manner so as to prevent changes in the current flowing from the power source to the transceiver and the capacitor caused by the transceiver switching between sleeping and listening/transmission operation and vice versa, respectively, which are expected to add an audible noise signal to the audio signals supplied to the stimulation means.

31. The method for providing hearing assistance to at least one user according to claim 30, wherein the digital transceiver listens and transmits during part of each frame and sleeps during the remainder of the frame.