Hearing device with a microphone

1. A hearing device comprising a microphone ( 1 ; 1 ′; 26 ) wherein the microphone ( 1 ; 1 ′; 26 ) comprises a first opening ( 8 ), a second opening ( 9 ) and at least three compartments ( 2 ; 3 ; 4 ; 5 ; 29 ; 30 ), a first membrane ( 6 ) being arranged between the first and the second compartment ( 2 ; 3 ) and a second membrane ( 7 ) at least partly covering the third compartment ( 4 ), wherein the second and the third compartments ( 3 , 4 ) are connected in communicative manner via a canal ( 11 ; 11 ″), characterized in that the second membrane ( 7 ) has an acoustical compliance ratio (Ka) with respect to the first membrane ( 6 ) in a range of 0.3 to 3 according to a formula (I):

Ka

=

C

1

C

m

;

(

I

)

wherein Cm is the compliance of the first membrane ( 6 ) below its resonance frequency and C 1 is the compliance of the second membrane ( 7 ).

2. A hearing device according to claim 1 , characterized in that the second membrane ( 7 ) comprises a plastic film made out of polyester or a metal foil made out of titanium or aluminium.

3. A hearing device comprising a microphone ( 1 ; 1 ′; 26 ) wherein the microphone ( 1 ; 1 ′; 26 ) comprises a first opening ( 8 ), a second opening ( 9 ) and at least three compartments ( 2 ; 3 ; 4 ; 5 ; 29 ; 30 ), a first membrane ( 6 ) being arranged between the first and the second compartment ( 2 ; 3 ) and a second membrane ( 7 ) at least partly covering the third compartment ( 4 ), wherein the second and the third compartments ( 3 , 4 ) are connected in communicative manner via a canal ( 11 ; 11 ″), characterized in that the second membrane ( 7 ) comprises a plastic film made out of polyester or a metal foil made out of titanium or aluminium, and the plastic film or the metal foil has a thickness (a) in the range of 2 μm to 20 μm, in particular in the range of 5 μm to 15 μm.

4. A hearing device according to claim 1 , characterized in that at least one of the membranes comprises a passage ( 23 ).

5. A hearing device comprising a microphone ( 1 ; 1 ′; 26 ) wherein the microphone ( 1 ; 1 ′; 26 ) comprises a first opening ( 8 ), a second opening ( 9 ) and at least three compartments ( 2 ; 3 ; 4 ; 5 ; 29 ; 30 ), a first membrane ( 6 ) being arranged between the first and the second compartment ( 2 ; 3 ) and a second membrane ( 7 ) at least partly covering the third compartment ( 4 ), wherein the second and the third compartments ( 3 , 4 ) are connected in communicative manner via a canal ( 11 ; 11 ″), characterized in that a second microphone ( 1 ″) is acoustically connected to the first microphone ( 1 ; 1 ′) via a third canal ( 11 ″), the third canal ( 11 ″) comprising a first canal part ( 27 ) and a second canal part ( 28 ).

6. A hearing device according to claim 5 , characterized in that the second microphone ( 1 ″) comprises only means for fastening and tensioning the second membrane ( 7 ).

7. A hearing device according to claim 5 , characterized in that a signal of the first microphone ( 1 ; 1 ′) and another signal of the second microphone ( 1 ″) are electrically combined.

8. A hearing device according to claim 1 , wherein the hearing device is a behind-the-ear hearing device.

9. A hearing device according to claim 1 , wherein the at least three compartments, the first membrane, and the second membrane are arranged asymmetrically.

10. A hearing device according to claim 1 , wherein the second membrane ( 7 ) covers the second opening ( 9 ).

11. A hearing device according to claim 1 , wherein the first opening ( 8 ) is acoustically connected to the first compartment ( 2 ) and the second opening ( 9 ) is acoustically connected to the third compartment ( 4 ).

12. A hearing device according to claim 1 , characterized in that the canal ( 11 ; 11 ″) has an acoustical mass (Ma) of >300 kg/m 4 .

13. A hearing device according to claim 1 , characterized in that a distance (d) between the two openings ( 8 ; 9 ) is in the range of 5 mm to 15 mm.

14. A hearing device comprising a microphone ( 1 ; 1 ′; 26 ) wherein the microphone ( 1 ; 1 ′; 26 ) comprises a first opening ( 8 ), a second opening ( 9 ) and at least three compartments ( 2 ; 3 ; 4 ; 5 ; 29 ; 30 ), a first membrane ( 6 ) being arranged between the first and the second compartment ( 2 ; 3 ) and a second membrane ( 7 ) at least partly covering the third compartment ( 4 ), wherein the second and the third compartments ( 3 , 4 ) are connected in communicative manner via a canal ( 11 ; 11 ″), characterized in that the hearing device comprises at least a fourth compartment ( 29 ), and in that the fourth compartment ( 29 ) comprises the first opening ( 8 ), and characterized in that the hearing device comprises a further canal ( 11 ′) and a third membrane ( 7 ′), wherein the further canal ( 11 ′) connects the fourth compartment ( 29 ) and the first compartment ( 2 ), the third compartment ( 4 ) comprising the second opening ( 9 ) where the second membrane ( 7 ) is located and the third membrane ( 7 ′) at least partly covers the first opening ( 8 ) of the fourth compartment ( 29 ).

15. A hearing device according to claim 14 , characterized in that the third compartment ( 4 ) and the fourth compartment ( 29 ) are of a same volume size (V 3 ; V 5 ) or of a different volume size (V 5 ; V 6 ).

16. A hearing device according to claim 14 , characterized in that the third membrane ( 7 ′) comprises a plastic film made out of polyester or a metal foil made out of titanium or aluminium.

17. A hearing device according to claim 14 , characterized in that the third membrane ( 7 ′) has another acoustical compliance ratio (Kb) with respect to the second membrane ( 7 ) in another range of 1.1 to 1.5 according to a formula (II):

Kb

=

C

2

C

1

;

(

II

)

wherein C 1 is the compliance of the second membrane ( 7 ) below its resonance frequency and C 2 is the compliance of the third membrane ( 7 ′).