Hearing aid with magnetostrictive electroactive sensor

• US 8,649,541 B2
• Filed: 07/11/2011
• Issued: 02/11/2014
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: Starkey Laboratories Incorporated
• Original Assignee: Starkey Laboratories Incorporated
• Inventors: Newton, James R., Sacha, Michael Karl, Lin, Wei Li
• Primary Examiner(s): Goins, Davetta W
• Assistant Examiner(s): Ojo, Oyesola C
• Application Number:
  US13/179,784
• Publication Number:
  US 20130016862A1
• Time in Patent Office: 946 Days
• Field of Search: 381/323, 381/190, 381/173, 381/314, 381/331, 381/328, 381/315, 381/312, 320/107, 320/108, 320/114, 136/205, 429/96, 429/98, 429/100, 600/25, 607 51- 57
• US Class Current: 381/323
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H04R 2225/31 Aspects of the use of accumulators in hearing aids, e.g. rechargeable batteries or fuel cells
• CPC Class Codes: H04R 2225/61 Aspects relating to mechanical or electronic switches or control elements, e.g. functioning
• CPC Class Codes: H04R 25/43 Electronic input selection or mixing based on input signal analysis, e.g. mixing or selection between microphone and telecoil or between microphones with different directivity characteristics H04R25/407 takes precedence
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils
• CPC Class Codes: H04R 25/558 Remote control, e.g. of amplification, frequency
• CPC Class Codes: H04R 25/603 of mechanical or electronic switches or control elements
• CPC Class Codes: H04R 25/658 Manufacture of housing parts

Abstract

A hearing aid includes a magnetostrictive electroactive (ME) sensor that generates an electrical signal in response to a magnetic field or a mechanical pressure. In various embodiments, the ME sensor is used for cordless charging of a rechargeable battery in the hearing aid by generating an electrical signal in response to a magnetic field generated for power transfer, magnetic sound signal reception, and/or detection of user commands by sensing a magnetic field or a pressure applied to the hearing aid.

Claims

1. A hearing aid, comprising:

a hearing aid circuit including a microphone, a receiver, and an audio processor coupled between the microphone and the receiver;

a rechargeable battery coupled to the hearing aid circuit to power the hearing aid circuit;

a magnetostrictive electroactive (ME) sensor configured to generate a power signal in response to a first magnetic field and generate a driving signal in response to a second magnetic field or a pressure; and

a sensor processing circuit coupled to the ME sensor, the sensor processing circuit including;

a battery charging circuit coupled to the rechargeable battery and configured to charge the rechargeable battery using the power signal; and

a switch coupled to the hearing aid circuit and configured to control the hearing aid circuit using the driving signal.

2. The hearing aid of claim 1, comprising a housing encapsulating at least the hearing aid circuit and the sensor processing circuit.

3. The hearing aid of claim 2, wherein the ME sensor is encapsulated in the housing.

4. The hearing aid of claim 2, wherein the ME sensor is incorporated into the housing.

5. The hearing aid of claim 4, wherein the housing comprises a battery door, and the ME sensor is incorporated into the battery door.

6. The hearing aid of claim 1, wherein the ME sensor comprises two magnetostrictive layers and a piezoelectric layer sandwiched between the two magnetostrictive layers.

7. The hearing aid of claim 1, wherein the ME sensor is configured to scavenge power from environmental magnetic fields.

8. The hearing aid of claim 7, wherein the ME sensor is configured to scavenge power from magnetic fields generated by electric power lines.

9. The hearing aid of claim 1, wherein the ME sensor is configured to generate a sound signal in response to a third magnetic field representing a sound, and the sensor processing circuit comprises a sound processing circuit configured to process the sound signal to recover the sound from the sound signal.

10. The hearing aid of claim 1, wherein the switch comprises a magnetic switch driven by the driving signal, and the ME sensor is configured to generate the driving signal in response to the command magnetic field applied on the ME sensor for at least a specified duration.

11. The hearing aid of claim 1, wherein the command magnetic field is modulated by data representative of user commands, the ME sensor is configured to generate the driving signal in response to the command magnetic field applied on the ME sensor, the driving signal including the data representative of the user commands, and the switch is configured to control the hearing aid circuit according to the user commands.

12. The hearing aid of claim 1, wherein the switch comprises a touch switch driven by the driving signal, and the ME sensor is configured to generate the driving signal in response to a mechanical pressure applied on the ME sensor for at least a specified duration.

13. A method for operating a hearing aid powered by a rechargeable battery, the method comprising:

generating a power signal in response to a first magnetic field applied to the hearing aid using a magnetostrictive electroactive (ME) sensor in the hearing aid;

converting the power signal into a DC electrical signal;

charging the rechargeable battery using the DC electrical signal;

detecting a user command as a second magnetic field or a pressure applied to the hearing aid using the ME sensor; and

adjusting an operation of the hearing aid in response to the user command.

14. The method of claim 13, comprising generating the power signal using the ME sensor in response to a magnetic field generated by a hearing aid charger using a coil.

15. The method of claim 13, comprising generating the power signal by scavenging power from environmental magnetic fields using the ME sensor.

16. The method of claim 15, wherein scavenging the power from the environmental magnetic fields comprises scavenging power from magnetic fields generated by power lines carrying AC current of approximately 60 Hz.

17. The method of claim 13, further comprising generating a sound signal in response to a third magnetic field representing a sound, and processing the sound signal to recover the sound.

18. The method of claim 13, comprising generating a driving signal suitable for driving a switch in the hearing aid in response to the second magnetic field using the ME sensor.

19. The method of claim 18, wherein generating the driving signal comprises generating the driving signal in response to presence of a magnet in proximity of the hearing aid.

20. The method of claim 18, wherein the second magnetic field is modulated by data representative of the user command, and generating the driving signal comprises generating a driving signal including the data representative of the user command in response to the second magnetic field being applied to the hearing aid using an electromagnet.

21. The method of claim 13, comprising generating a driving signal suitable for driving a switch in the hearing aid in response to the pressure using the ME sensor.

22. The method of claim 21, wherein generating the driving signal comprises generating the driving signal in response to a portion of the hearing aid being touched.

23. The method of claim 13, comprising turning the hearing aid on or off in response to the user command.

24. The method of claim 13, comprising adjusting sound volume of the hearing aid in response to the user command.

25. A hearing aid, comprising:

a hearing aid circuit including a microphone, a receiver, and an audio processor coupled between the microphone and the receiver;

a rechargeable battery coupled to the hearing aid circuit to power the hearing aid circuit;

a magnetostrictive electroactive (ME) sensor configured to scavenge power from magnetic fields generated from electric power lines carrying AC current having a power line frequency of approximately 60 Hz and generate a power signal using the scavenged power, the ME sensor tuned to the power line frequency; and

a battery charging circuit coupled to the rechargeable battery and the ME sensor, the battery charging circuit configured to charge the rechargeable battery using the power signal.

26. The hearing aid of claim 25, wherein the ME sensor comprises two magnetostrictive layers and a piezoelectric layer sandwiched between the two magnetostrictive layers.

27. The hearing aid of claim 26, further comprising a sound processing circuit coupled to the hearing aid circuit and the ME sensor, the sound processing circuit configured to receive a sound magnetically transmitted to the hearing aid, wherein the ME sensor is configured to generate a sound signal in response to a magnetic field representing the sound, and the sound processing circuit comprises a signal conditioner configured to condition the sound signal for recovering the sound.