Sealing retainer for extended wear hearing devices

• US 20060291682A1
• Filed: 06/13/2006
• Published: 12/28/2006
• Est. Priority Date: 11/25/1998
• Status: Active Grant

• Current Assignee: Insound Medical Incorporated (Sonova Holding AG)
• Original Assignee: Insound Medical Incorporated (Sonova Holding AG)
• Inventors: Shennib, Adnan, Ram, Sunder, Anderson, Greg, Tilson, Alex, Sadler, John, Buckley, James, Schindler, Robert, Day, Ian, Urso, Richard Carl
• Granted Patent: US 7,580,537 B2
• Time in Patent Office: Days
• US Class Current: 381/328
• CPC Class Codes: H04R 2225/023 Completely in the canal [CIC] hearing aids
• CPC Class Codes: H04R 25/652 Ear tips; Ear moulds hybrid ear moulds or post-processing thereof for their customisation H04R25/659
• CPC Class Codes: H04R 25/658 Manufacture of housing parts

Abstract

Embodiments of the invention provide seals for retaining hearing devices in the ear canal. An embodiment provides a seal for a hearing device comprising a curved shell having a wall and an opening at a shell apex portion. The shell defines a cavity for retention of a device component. The shell wall has a shape configured to distribute compressive forces applied to the shell perimeter such that when the shell is positioned in the canal, the shell wall dynamically conforms to changes in the shape of the canal to maintain an acoustical seal between a shell exterior surface and the canal walls. The shell can include an anti-microbial coating to produce a reduction in bacteria contacting the coating. Also, the shell wall can have a water vapor transmission rate to reduce moisture accumulation in the canal during periods of extended wear to reduce the incidence of infection and otitis.

Claims

1. A seal for retaining a hearing device within a bony portion of the ear canal, the seal comprising:

a curved shell having a wall and an opening at an apex portion of the shell, the shell wall defining a cavity for retention of a hearing device component, at least a portion of the shell comprising a resilient material having sound attenuating properties;

wherein the shell wall is configured to distribute compressive forces applied to a shell perimeter such that when the shell is positioned in the ear canal, the shell wall dynamically conforms to changes in the shape of the ear canal to maintain an acoustical seal between an exterior surface of the shell and the walls of the ear canal.

2. The seal of claim 1, wherein the shell has a structure such that a force for removal of the seal from the ear canal is greater than a force for insertion of the seal into the canal.

3. The seal of claim 1, wherein the shell is sized to be positioned in the bony portion of the canal such that a residual volume in the canal is less than about 0.5 cc.

4. The seal of claim 1, wherein the shell wall has a shape configured to distribute the compressive forces to maintain the acoustical seal.

5. The seal of claim 1, wherein deformation in one portion of the shell wall does not appreciably effect a water vapor transmission rate in another portion.

6. The seal of claim 1, wherein the shell has an in situ water vapor transmission rate of at least about 3.0×

10<sup>−

3</sup> grams/day mmHg.

7. The seal of claim 1, wherein the shell has an in situ water vapor transmission rate of at least about 4.033 10⁻

3 grams/day mmHg.

8. The seal of claim 1, wherein the shell wall has an in situ water vapor permeance of at least about 50 grams/day/m²/mmHg.

9. The seal of claim 1, wherein the shell wall has an in situ water vapor permeance of at least about 70 grams/day/m²/mmHg.

10. The seal of claim 1, wherein the shell wall has an in situ water vapor permeance of at least about 100 grams/day/m²/mmHg.

11. The seal of claim 1, wherein at least a portion of the seal includes an anti-microbial coating configured to produce about a three log reduction in colony forming units of bacteria contacting the coating.

12. The seal of claim 11, wherein the coating includes at least one of an anti-microbial agent, a silver based anti-microbial agent or an antibiotic.

13. The seal of claim 12, wherein the anti-microbial agent or antibiotic is configured to be eluted from the coating for an extended period of wear in the ear canal.

14. The seal of claim 13, wherein the period of extended wear is up to six months.

15. The seal of claim 1, wherein the seal is configured to achieve at least about three decibels of attenuation in sound in the audible frequency range between a medial and lateral portion of the shell when the shell is positioned in the ear canal.

16. The seal of claim 1, wherein the seal is configured to achieve at least about ten decibels of attenuation in sound in the audible frequency range between a medial and lateral portion of the shell when the shell is positioned in the ear canal.

17. The seal of claim 1, wherein the shell is configured such that a spring pressure exerted by the shell on the walls of the ear canal does not exceed about 12 mmHg.

18. The seal of claim 1, wherein the shell is configured such that a spring pressure exerted by the shell on the walls of the ear canal does not exceed about 6 mmHg.

19. The seal of claim 1, wherein the shell is configured such that a spring pressure exerted by the shell on the walls of the ear canal is in the range of about 2 to about 6 mmHg.

20. The seal of claim 1, wherein the shell has a stiffniess configured to allow the shell to conform to the shape of the ear canal for a radial deformation of up to about 10 per cent of a diameter of the shell.

21. The seal of claim 1, wherein the shell has a stiffness configured to allow the shell to conform to the shape of the ear canal for a radial deformation of up to about 20 per cent of a diameter of the shell.

22. The seal of claim 1, wherein the shell wall has an in situ water vapor transmission rate configured to minimize an accumulation of moisture in the canal when the seal is in the canal for an extended period.

23. The seal of claim 1, wherein the shell wall has an in situ water vapor transmission rate configured to allow substantial equilibrium between a relative humidity in a bony portion of the ear canal when the seal is in the canal and a relative humidity of ambient air outside the ear.

24. The seal of claim 1, wherein the seal has an axial length in the range between about 5 to about 10 mms.

25. The seal of claim 1, wherein the seal is configured to be seated in a bony portion of the ear canal.

26. A CIC hearing aid for operation in a bony portion of an ear canal of a user, the hear aid comprising:

a microphone assembly;

a receiver assembly configured to supply acoustic signals received from the microphone assembly to a tympanic membrane of the user;

a battery assembly for powering the hearing aid, the battery assembly electrically coupled to at least one of the microphone assembly or the receiver assembly; and

the seal of claim 1, wherein the seal is coupled to one of the battery assembly, the microphone assembly or the receiver assembly.

27. The hearing aid of claim 26, wherein the seal comprises a first seal and a second seal.

28. The hearing aid of claim 27, wherein the first and second seals are configured to be medially and laterally positioned with respect to a bend in the ear canal.

29. The hearing aid of claim 27, wherein the seals retain the receiver assembly and the battery assembly at an angular offset with respect to each other.

30. The hearing aid of claim 27, wherein the first seal is coupled to the receiver assembly and the second seal is coupled to the battery assembly or the microphone assembly.

31. The hearing aid of claim 30, wherein the first seal centers the receiver assembly at a first location in the ear canal and the second seal centers the microphone or battery assembly at a second location in the ear canal.

32. The hearing aid of claim 27, wherein the second seal augments the acoustical attenuation of the first seal.

33. The hearing aid of claim 26, wherein the hearing aid has a water vapor transmission rate configured to reduce an incidence of otitis of the ear canal.

34. The hearing aid of claim 26, wherein the hearing aid has an in situ water vapor transmission rate of at least about 2.0×

10<sup>−

3</sup> grams/day/mmHg.

35. The hearing aid of claim 26, wherein the hearing aid has an in situ water vapor transmission rate of at least about 4.0×

10<sup>−

3</sup> grams/day/mmHg.

36. A seal for retaining a hearing device within a bony portion of the ear canal, the seal comprising:

a curved shell having a wall and an opening at an apex portion of the shell, the shell wall defining a cavity for retention of a hearing device component, at least a portion of the shell comprising a resilient material having sound attenuating properties and at least a portion of the shell including an anti-microbial coating configured to produce at least about a three log reduction in colony forming units of bacteria contacting the coating;

wherein the shell wall is configured to distribute compressive forces applied to a shell perimeter such that when the shell is positioned in the ear canal, the shell wall dynamically conforms to changes in the shape of the ear canal to maintain an acoustical seal between an exterior surface of the shell and the walls of the ear canal.

37. A seal for retaining a hearing device within a bony portion of the ear canal, the seal comprising:

a curved shell having a wall and an opening at an apex portion of the shell, the shell wall defining a cavity for retention of a hearing device component, at least a portion of the shell comprising a resilient material having sound attenuating properties wherein the shell wall has an in situ water vapor permeance of at least about 50 grams/day/m²/mmHg.

38. The seal of claim 37, wherein the shell wall has an in situ water vapor permeance of at least about 70 grams/day/m²/mmHg.

39. A method for wearing a hearing device in the ear canal of a user, the method comprising:

providing a hearing device having a retaining seal configured to retain the device in the ear canal, the seal allowing a water vapor transmission rate between a portion of the ear canal medial to the hearing device and a portion lateral to the hearing device of at least about 2.0×

10−

3 grams/day/mmHg;

positioning the hearing device at a location in the ear canal; and

wearing the device in the canal on a substantially continuous basis while substantially preserving an integrity of an epithelial layer in contact with the seal.

40. The method of claim 39, wherein the water vapor transmission rate is at least about 4.0×

10−

3 grams/day/mmHg.

41. The method of claim 39, wherein the seal comprises a first seal and a second seal.

42. The method of claim 39, wherein the device is worn continuously in the ear canal without substantial ulceration or necrosis of the epithelial layer.

43. The method of claim 39, wherein the device is worn for a period of up to about six months.

44. The method of claim 39, wherein the hearing device is worn in a bony portion of the ear canal.

45. The method of claim 39, wherein the seal allows a substantial equilibrium in humidity between a bony portion of the ear canal and an external portion of the ear.