Directional microphone assembly

• US 6,285,771 B1
• Filed: 10/13/2000
• Issued: 09/04/2001
• Est. Priority Date: 12/31/1996
• Status: Expired due to Fees

• Current Assignee: Etymotic Research Incorporated
• Original Assignee: Etymotic Research Incorporated
• Inventors: Monroe, Timothy S., Killion, Mead C., Stewart, Jonathan, Wilson, Don, Iseberg, Steve, Roberts, Matthew J.
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): PENDLETON, DIONNE
• Application Number:
  US09/687,336
• Time in Patent Office: 326 Days
• Field of Search: 381/313, 381/91, 381/355, 381/324, 381/356, 381/329, 381/357, 381/381, 381/358, 381/361
• US Class Current: 381/313
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2225/025 In the ear hearing aids [ITE] hearing aids
• CPC Class Codes: H04R 2225/41 Detection or adaptation of hearing aid parameters or programs to listening situation, e.g. pub, forest
• CPC Class Codes: H04R 2225/43 Signal processing in hearing aids to enhance the speech intelligibility
• CPC Class Codes: H04R 2410/01 Noise reduction using microphones having different directional characteristics
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 25/02 adapted to be supported entirely by ear
• CPC Class Codes: H04R 25/405 by combining a plurality of transducers
• CPC Class Codes: H04R 25/456 mechanically
• CPC Class Codes: H04R 25/604 of acoustic or vibrational transducers
• CPC Class Codes: H04R 25/65 Housing parts, e.g. shells, tips or moulds, or their manufacture

Abstract

A microphone capsule for an in-the-ear hearing aid is disclosed. The capsule can include a top plate having first and second spaced openings defining front and rear sound inlets, and a directional microphone cartridge enclosing a diaphragm. The diaphragm is oriented generally perpendicular to the top plate and divides the directional microphone cartridge housing into a front chamber and a rear chamber. A front sound passage communicates between the front sound inlet and the front chamber, and a rear sound passage communicates between the rear sound inlet and the rear chamber. Front and rear acoustic damping resistors are associated with the front and rear sound passages. The acoustic resistor pair provides a selected time delay, such as about 4 microseconds, between the front and rear sound passages. The use of two acoustic resistors instead of one levels the frequency response, compared to the frequency response provided by a rear acoustic damping resistor alone.

Claims

1. An in-the-ear hearing aid comprising:

A. a hearing aid housing; and

B. a directional microphone comprising

(i) a directional microphone cartridge having a directional microphone cartridge housing and a diaphragm mounted within said directional microphone cartridge housing, said diaphragm dividing said directional microphone cartridge housing into a front chamber and a rear chamber;

(ii) a front sound passage communicating with said front chamber; and

(iii) a rear sound passage communicating with said rear chamber;

wherein the hearing aid provides an in-ear polar response resulting in an Articulation-Index weighted average Directivity Index of at least 4.7 dB.

2. The hearing aid of claim 1 wherein the hearing aid provides an in-ear polar response having a Directivity Index of at least 6.0 dB in the 2-4 kHz range.

3. The hearing aid of claim 1 wherein the in-ear polar response is measured on a KEMAR manikin.

4. The hearing aid of claim 2 wherein the measurement is taken in an anechoic chamber.

5. The hearing aid of claim 1 wherein the in-ear polar response is measured over a frequency range of approximately 0.5 to 8 kHz.

6. The hearing aid of claim 1 wherein said directional microphone housing has a front opening communicating between said front sound passage and said front chamber and a rear opening communicating between said rear sound passage and said rear chamber.

7. The hearing aid of claim 1 further comprising a plate, and wherein an outer surface of said plate defines an exterior portion of an outer surface of said hearing aid housing.

8. The hearing aid of claim 7 wherein said plate has front and rear sound paths located therein, said front sound path communicating between a sound field exterior to said plate and said front sound passage, and said rear sound path communicating between said sound field exterior to said plate and said rear sound passage.

9. The hearing aid of claim 8 wherein said plate receives said front and rear sound passages such that the front sound path couples with the front sound passage and the rear sound path couples with the rear sound passage.

10. An in-the-ear hearing aid comprising:

A. a plate having an outer surface defining an exterior surface of said hearing aid as worn; and

B. a directional microphone comprising

(i) a directional microphone cartridge comprising a directional microphone cartridge housing and a diaphragm mounted within said directional microphone cartridge housing, said diaphragm dividing said directional microphone cartridge housing into a front chamber and a rear chamber, said directional microphone cartridge housing having a front opening and a rear opening;

(ii) a front sound passage for receiving sound from a sound field external to said plate, said front sound passage communicating with said front chamber through said front opening in said directional microphone cartridge housing; and

(iii) a rear sound passage for receiving sound from a sound field external to said plate, said rear sound passage communicating with said rear chamber though said rear opening in said directional microphone cartridge housing;

wherein the hearing aid provides an in-ear polar response resulting in an Articulation Index weighted average Directivity Index of at least 4.7 dB.

11. The hearing aid of claim 10 wherein the hearing aid provides an in-ear polar response having a Directivity Index of at least 6.0 dB in the 2-4 kHz range.

12. The hearing aid of claim 10 wherein the in-ear polar response is measured on a KEMAR manikin.

13. The hearing aid of claim 12 wherein the measurement is taken in an anechoic chamber.

14. The hearing aid of claim 10 wherein the in-ear polar response is measured over a frequency range of approximately 0.5 to 8 kHz.

15. The hearing aid of claim 10 further comprising a hearing aid housing, and wherein said plate forms a portion of an outer surface of said hearing aid housing.

16. The hearing aid of claim 15 wherein said plate has front and rear sound paths located therein, said front sound path communicating between said sound field and said front sound passage, and said rear sound path communicating between said sound field and said rear sound passage.

17. The hearing aid of claim 16 wherein said plate receives said front and rear sound passages such that the front sound path couples with the front sound passage and the rear sound path couples with the rear sound passage.

18. An in-the-ear hearing aid comprising:

a plate having an outer surface defining an exterior surface of said hearing aid as worn; and

a directional microphone comprising

a front sound passage for receiving sound from a sound field external to said plate; and

a rear sound passage for receiving sound from a sound field external to said plate;

wherein the hearing aid provides an in-ear polar response resulting in an Articulation Index weighted average Directivity Index of at least 4.7 dB.

19. The hearing aid of claim 18 wherein the hearing aid provides an in-ear polar response having a Directivity Index of at least 6.0 dB in the 2-4 kHz range.

20. The hearing aid of claim 18 wherein the in-ear polar response is measured on a KEMAR manikin.

21. The hearing aid of claim 20 wherein the measurement is taken in an anechoic chamber.

22. The hearing aid of claim 18 wherein the in-ear polar response is measured over a frequency range of approximately 0.5 to 8 kHz.

23. The hearing aid of claim 18 wherein the directional microphone further comprises a single directional microphone cartridge.

24. The hearing aid of claim 18 further comprising a hearing aid housing, and wherein said plate defines a portion of an outer surface of said hearing aid housing.

25. The hearing aid of claim 18 wherein said plate has front and rear sound paths located therein, said front sound path communicating between said sound field and said front sound passage, and said rear sound path communicating between said sound field and said rear sound passage.

26. The hearing aid of claim 25 wherein said plate receives said front and rear sound passages such that the front sound path couples with the front sound passage and the rear sound path couples with the rear sound passage.

27. An in-the-ear hearing aid comprising:

a hearing aid housing; and

a directional microphone comprising

a front sound passage; and

a rear sound passage;

wherein the hearing aid provides an in-ear polar response resulting in an Articulation Index weighted average Directivity Index of at least 4.7 dB.

28. The hearing aid of claim 27 wherein the hearing aid provides an in-ear polar response having a Directivity Index of at least 6.0 dB in the 2-4 kHz range.

29. The hearing aid of claim 27 wherein the in-ear polar response is measured on a KEMAR manikin.

30. The hearing aid of claim 29 wherein the measurement is taken in an anechoic chamber.

31. The hearing aid of claim 27 wherein the in-ear polar response is measured over a frequency range of approximately 0.5 to 8 kHz.

32. The hearing aid of claim 27 further comprising a plate, and wherein an outer surface of said plate defines an exterior portion of an outer surface of said hearing aid housing.

33. The hearing aid of claim 32 wherein said plate has front and rear sound paths located therein, said front sound path communicating between a sound field exterior to said plate and said front sound passage, and said rear sound path communicating between said sound field exterior to said plate and said rear sound passage.

34. The hearing aid of claim 33 wherein said plate receives said front and rear sound passages such that the front sound path couples with the front sound passage and the rear sound path couples with the rear sound passage.

35. The hearing aid of claim 27 wherein the directional microphone further comprises a single directional microphone cartridge.

36. An in-the-ear hearing aid comprising:

a plate having an outer surface defining an exterior surface of said hearing aid as worn, said plate having first and second sound paths therethrough, said first and second sound paths for receiving sound from a sound field external to said plate; and

a directional microphone comprising

a directional microphone cartridge having a directional microphone cartridge housing, said directional microphone cartridge housing having first and second openings therein;

a first sound passage acoustically coupled to said first opening in said directional microphone cartridge housing and to said first sound path in said plate, said first sound passage for receiving sound from said first sound path in said plate and for coupling received sound to said first opening in said directional microphone cartridge housing; and

a second sound passage acoustically coupled to said second opening in said directional microphone cartridge housing and to said second sound path in said plate, said second sound passage for receiving sound from said second sound path in said plate and for coupling received sound to said second opening in said directional microphone cartridge housing;

wherein the hearing aid provides an in-ear polar response resulting in an Articulation-Index weighted average Directivity Index of at least 4.7 dB.

37. The hearing aid of claim 36 further comprising a hearing aid housing, and wherein said plate forms a portion of an outer surface of said hearing aid housing.

38. The hearing aid of claim 36 wherein the hearing aid provides an in-ear polar response having a Directivity Index of at least 6.0 dB in the 2-4 kHz range.

39. The hearing aid of claim 36 wherein the in-ear polar response is measured on a KEMAR manikin.

40. The hearing aid of claim 39 wherein the measurement is taken in an anechoic chamber.

41. The hearing aid of claim 36 wherein the in-ear polar response is measured over a frequency range of approximately 0.5 to 8 kHz.

42. An in-the-ear hearing aid comprising a hearing aid housing and a directional microphone located in the housing, the hearing aid housing and directional microphone configured and arranged to provide an in-ear polar response resulting in an Articulation Index weighted average Directivity Index of at least 4.7 dB.

43. The hearing aid of claim 42 wherein the hearing aid provides an in-ear polar response having a Directivity Index of at least 6.0 dB in the 2-4 kHz range.

44. The hearing aid of claim 42 wherein the in-ear polar response is measured on a KEMAR manikin.

45. The hearing aid of claim 44 wherein the measurement is taken in an anechoic chamber.

46. The hearing aid of claim 42 wherein the in-ear polar response is measured over a frequency range of approximately 0.5 to 8 kHz.