In ear hearing device with a housing enclosing acoustically coupled chambers

1. A hearing device configured to be at least partially inserted into an ear canal, the hearing device comprising

an acoustic transducer having a membrane configured to generate sound waves;

a housing enclosing a first chamber and a second chamber acoustically coupled by the membrane;

a sound outlet configured to release sound waves from the first chamber into the ear canal; and

a first acoustic port acoustically coupling the second chamber to an ambient environment outside the ear canal;

characterized by

a resonant member configured to resonate with sound waves at a resonance frequency, wherein the second chamber is acoustically coupled to the resonant member at a second acoustic port positioned between the first acoustic port and the membrane of the acoustic transducer.

2. The hearing device according to claim 1 , characterized in that the resonant member comprises a displaceable mass and an elastic coupling counteracting a displacement of the mass, the mass comprising an interaction face at which sound waves can interact with the mass.

3. The hearing device according to claim 1 , characterized in that said resonance frequency of the resonant member is a first resonance frequency, wherein the second chamber resonates with the first acoustic port at a second resonance frequency, wherein the first resonance frequency deviates from the second resonance frequency at most by one octave.

4. The hearing device according to claim 1 , wherein the resonant member comprises a container enclosing a cavity, wherein the second acoustic port acoustically couples the second chamber to the cavity.

5. The hearing device according to claim 4 , characterized in that the housing comprises an inner surface delimiting the first chamber and the second chamber, wherein the second acoustic port at least partially extends along a portion of the inner surface.

6. The hearing device according to claim 4 , characterized in that a membrane plane is defined as a plane in which a maximum cross sectional area of the membrane extends, wherein the second acoustic port crosses the membrane plane.

7. The hearing device according to claim 4 , characterized in that the container forms an integral part of the housing.

8. The hearing device according to claim 4 , characterized in that the housing comprises a front end and a rear end facing in opposite directions, wherein the sound outlet is provided at the front end and the container extends at least partially across the rear end.

9. The hearing device according to claim 4 , characterized in that the container comprises an annular portion surrounding the first chamber and/or the second chamber.

10. The hearing device according to claim 1 , characterized in that the resonant member includes a resistive member configured to attenuate sound waves interacting with the resonant member.

11. The hearing device according to claim 10 , characterized in that the resistive member is placed in series with the second acoustic port.

12. The hearing device according to claim 1 , characterized in that the resonance frequency of the resonant member comprises a frequency between 100 Hz and 5000 Hz.

13. The hearing device according to claim 1 , wherein an acoustic impedance measurable at the membrane toward the second chamber has, within a third-octave band having a center frequency corresponding to the resonance frequency of the resonant member, an absolute value varying by at most a factor of two relative to an absolute value of an impedance at the resonance frequency of the resonant member.

14. The hearing device according to claim 1 , characterized by a microphone and a control circuit connected to the microphone and the acoustic transducer, the control circuit configured to provide for active noise cancelling.