Hearing aid having second order directional response

• US 7,103,191 B1
• Filed: 10/02/2001
• Issued: 09/05/2006
• Est. Priority Date: 04/13/1993
• Status: Expired due to Fees

• Current Assignee: Etymotic Research Incorporated
• Original Assignee: Etymotic Research Incorporated
• Inventors: Killion, Mead C.
• Primary Examiner(s): LE, HUYEN D
• Application Number:
  US09/969,064
• Time in Patent Office: 1,799 Days
• Field of Search: 381/312, 381/313, 381/322, 381/327, 381/328, 381/330, 381/355, 381/356, 381/357, 381/358, 381/FOR.127, 381/FOR.128, 381/FOR.133
• US Class Current: 381/313
• CPC Class Codes: H04R 25/407 Circuits for combining signals of a plurality of transducers
• 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 29/005 Microphone arrays
• CPC Class Codes: H04R 29/006 Microphone matching
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A hearing aid apparatus is disclosed that employs both an omnidirectional microphone and at least one directional microphone of at least the first order. The electrical signals output from the directional microphone are supplied to an equalization amplifier which at least partially equalizes the amplitude of the low frequency electrical signal components of the electrical signal with the amplitude of the mid and high frequency electrical signal components of the electrical signals of the directional microphone. A switching circuit accepts the signals output from both the omnidirectional microphone and the directional microphone. The switching circuit connects the signal from the omnidirectional microphone to an input of a hearing aid amplifier when the switching circuit is in a first switching state, and connects the output of the equalization circuit to the hearing aid amplifier input when the switching circuit is in a second switching state. The switching circuit may be automatically switched in response to sensed ambient noise levels.

Claims

1. A hearing aid comprising:

A. a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing having an outer surface comprising a face plate defining an exterior surface of said hearing aid housing as worn, said hearing aid housing being of size and shape to fit into the ear of the hearing aid user; and

B. a second order directional microphone mounted within said hearing aid housing, said second order directional microphone comprising a plurality of microphones, each of the plurality of microphones having

(i) a microphone housing;

(ii) a diaphragm mounted within the microphone housing, said diaphragm dividing said microphone housing into a first chamber and a second chamber; and

(iii) at least one sound passage communicating with at least the first chamber.

2. The hearing aid of claim 1 wherein the at least one sound passage comprises a first sound passage and a second sound passage, and wherein the first sound passage communicates with the first chamber and the second sound passage communicates with the second chamber.

3. The hearing aid of claim 1 wherein the plurality of microphones comprise a plurality of directional microphones.

4. The hearing aid of claim 3 wherein the plurality of directional microphones comprise a plurality of first order directional microphones.

5. A hearing aid comprising:

A. a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing having an outer surface comprising a face plate defining an exterior surface of said hearing aid housing as worn, said hearing aid housing being of size and shape to fit into the ear of the hearing aid user; and

B. a second order directional microphone mounted within said hearing aid housing, said second order directional microphone comprising a plurality of microphones, each of the plurality of microphones having

(i) a housing;

(ii) a diaphragm mounted within said housing, said diaphragm dividing said housing into a first chamber and a second chamber, said housing having at least a first opening; and

(iii) at least one sound passage for receiving sound from a sound field external to said outer surface, said sound passage communicating with said first chamber through said first opening in said housing.

6. The hearing aid of claim 5 wherein the at least one sound passage comprises a first sound passage and a second sound passage and the at least a first opening comprises a first opening and a second opening, and wherein the first sound passage communicates with the first chamber through the first opening and the second sound passage communicates with the second chamber through the second opening.

7. The hearing aid of claim 5 wherein the plurality of microphones comprise a plurality of directional microphones.

8. The hearing aid of claim 7 wherein the plurality of directional microphones comprise a plurality of first order directional microphones.

9. A hearing aid comprising:

a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing having an outer surface comprising a face plate defining an exterior surface of said hearing aid housing as worn, said hearing aid housing being of size and shape to fit into the ear of the hearing aid user; and

a second order directional microphone mounted within the hearing aid housing, comprising

a plurality of microphones;

a first sound passage for receiving sound from a sound field external to said outer surface;

a second sound passage for receiving sound from a sound field external to said outer surface; and

a third sound passage for receiving sound from a sound field external to said outer surface.

10. The hearing aid of claim 9 wherein the plurality of microphones comprise a plurality of directional microphones.

11. The hearing aid of claim 10 wherein the plurality of directional microphones comprise a plurality of first order directional microphones.

12. A hearing aid comprising:

a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing being of site and shape to fit into the ear of the hearing aid user;

a face plate that forms an outer surface of said hearing aid housing; and

a second order directional microphone mounted within the hearing aid housing, the second order directional microphone comprising

a plurality of microphones;

a first sound passage;

a second sound passage; and

a third sound passage.

13. The hearing aid of claim 12 wherein the plurality of microphones comprise a plurality of directional microphones.

14. The hearing aid of claim 13 wherein the plurality of directional microphones comprise a plurality of first order directional microphones.

15. A hearing aid comprising:

a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing being of size and shape to fit into the ear of the hearing aid user and having an outer surface defining an exterior surface of a hearing aid housing as worn, said outer surface comprising a face plate and having first, second and third sound openings therein, said first, second and third sound openings for receiving sound from a sound field external to said outer surface; and

a second order directional microphone mounted within said hearing aid housing, comprising

a plurality of microphones;

a first sound passage acoustically coupled to said first opening in said outer surface, said first sound passage for receiving sound from said sound field and for coupling received sound to one of said plurality of microphones;

a second sound passage acoustically coupled to said second opening in said outer surface, said second sound passage for receiving sound from said sound field and for coupling received sound to one of said plurality of microphones; and

a third sound passage acoustically coupled to said third opening in said outer surface, said third sound passage for receiving sound from said sound field and for coupling received sound to one of said plurality of microphones.

16. The hearing aid of claim 15 wherein the plurality of microphones comprise a plurality of directional microphones.

17. The hearing aid of claim 16 wherein the plurality of directional microphones comprises a plurality of first order directional microphones.

18. A hearing aid comprising:

a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing being of size and shape to fit into the ear of the hearing aid user and having an outer surface defining an exterior surface of said hearing aid housing as worn, said outer surface comprising a face plate;

a plurality of microphones mounted within the hearing aid housing;

a first sound passage for receiving sound from a sound field external to said outer surface;

a second sound passage for receiving sound from a sound field external to said outer surface; and

a third sound passage for receiving sound from a sound field external to said outer surface;

the hearing aid providing a second order directional response.

19. The hearing aid of claim 18 wherein the plurality of microphones comprise three microphones.

20. The hearing aid of claim 18 wherein the plurality of microphones comprise a plurality of directional microphones.

21. The hearing aid of claim 20 wherein the plurality of directional microphones comprise a plurality of first order directional microphones.

22. The hearing aid of claim 18 wherein the plurality of microphones comprise at least one omnidirectional microphone.

23. A hearing aid comprising:

a hearing aid housing for mounting with an ear of a hearing aid user, the hearing aid housing being of size and shape to fit into the ear of the hearing aid user and having an outer surface defining an exterior surface of a hearing aid housing as worn, said outer surface comprising a face plate and having first, second and third sound openings therein, said first, second and third sound openings for receiving sound from a sound field external to said outer surface; and

a plurality of microphones mounted within said hearing aid housing;

a first sound passage acoustically coupled to said first opening in said outer surface, said first sound passage for receiving sound from said sound field and for coupling received sound to one of said plurality of microphones;

a second sound passage acoustically coupled to said second opening in said outer surface, said second sound passage for receiving sound from said sound field and for coupling received sound to one of said plurality of microphones; and

a third sound passage acoustically coupled to said third opening in said outer surface, said third sound passage for receiving sound from said sound field and for coupling received sound to one of said plurality of microphones;

the hearing aid providing a second order directional response.

24. The hearing aid of claim 23 wherein the plurality of microphones comprise three microphones.

25. The hearing aid of claim 23 wherein the plurality of microphones comprise a plurality of directional microphones.

26. The hearing aid of claim 25 wherein the plurality of directional microphones comprise a plurality of first order directional microphones.

27. The hearing aid of claim 23 wherein the plurality of microphones comprise at least one omnidirectional microphone.