High transmission loss headphone cushion
A headset including an earcup having a front opening adapted to be adjacent to the ear of the user, a baffle disposed within the earcup to define front and rear cavities, a cushion extending around the periphery of the front opening of the earcup and constructed and arranged to accommodate the ear of the user, the cushion having a first density, an inner radial portion, and an outer radial portion opposite the inner radial portion, a cushion cover substantially surrounding the cushion to form a headphone cushion assembly, and a high impedance component having a second density and located near the outer radial portion to increase the transmission loss of the cushion along a radial direction.
1. A headset comprising:
an earcup having a front opening adapted to be adjacent to the ear of the user;
a baffle disposed within the earcup to define front and rear cavities;
a cushion extending around the periphery of the front opening of the earcup and constructed and arranged to accommodate the ear of the user, the cushion having a first density, an inner radial portion, and an outer radial portion opposite the inner radial portion;
a cushion cover substantially surrounding the cushion to form a headphone cushion assembly; and
a high impedance component having a second density and being disposed radially outward from the cushion, between the outer radial portion of the cushion and the cushion cover, to increase the transmission loss of the cushion along a radial direction.
2. The headset of claim 1 further comprising a transducer inside the earcup.
3. The headset of claim 1 wherein the second density is higher than the first density.
4. The headset of claim 1 wherein a second high impedance component is interposed between the inner radial portion of the cushion and the cushion cover.
5. The headset of claim 1 wherein the high impedance component is disposed adjacent the cushion cover.
6. The headset of claim 1 wherein the high impedance component comprises a rigid ring.
7. The headset of claim 1 wherein the high impedance component comprises a colloidal ring.
8. The headset of claim 7 wherein the high impedance component comprises a gel layer.
9. The headset of claim 1 wherein the high impedance component comprises a polyurethane foam.
10. The headset of claim 1 wherein the cushion cover comprises a plurality of openings extending along the inner radial portion of the cushion to acoustically add the volume of the cushion to the volume of the earcup and enhance passive attenuation of the headset.
11. The headset of claim 1 wherein the cushion cover comprises an acoustically transparent mesh along the inner radial portion of the cushion to acoustically add the volume of the cushion to the volume of the earcup and enhance passive attenuation of the headset.
12. The headset of claim 1 wherein the outer radial portion of the cushion has an average area density greater than about 0.03 g/cm 2 and the headphone cushion assembly has an axial stiffness per contact area less than about 8 gf/mm/cm 2 .
13. The headset of claim 1 wherein the headphone cushion assembly has an axial stiffness per contact area less than about 4 gf/mm/cm 2 .
14. The headset of claim 1 wherein the headphone cushion assembly comprises a toroidal shape.
15. The headset of claim 1 wherein the headphone cushion assembly is circumaural.
16. The headset of claim 1 wherein the headphone cushion assembly is supra-aural.
17. The headset of claim 1 further comprising:
a microphone inside the earcup adjacent to a driver; and
active noise reducing circuitry intercoupling the microphone and the driver constructed and arranged to provide active noise cancellation.
18. The headset of claim 17 wherein the inner radial portion of the cushion cover is constructed and arranged to furnish additional damping to help smooth an audio response at an ear of a user and control stability when the headset is not being worn on a head of the user.
19. The apparatus of claim 18 wherein the cushion cover comprises a plurality of openings such that the volume of the cushion is acoustically added to the volume of the earcup.
20. The apparatus of claim 18 wherein the cushion adheres to the cushion cover with a peel strength greater than about 0.1 gf/mm.
21. The apparatus of claim 18 wherein the cushion adheres to the cushion cover with a peel strength greater than about 0.4 gf/mm.
22. The apparatus of claim 18 wherein the cushion comprises open cell foam.
23. The apparatus of claim 18 wherein the cushion has a bulk density between about 2 pcf and about 6 pcf.
24. The apparatus of claim 18 wherein the cushion has an elastic modulus between about 1 kPa and about 10 kPa.
25. The apparatus of claim 18 wherein the cushion has an elastic modulus between about 2 kPa and about 5 kPa.
26. The apparatus of claim 1 wherein the high impedance component comprises a silicone material.
27. A headphone cushion assembly comprising:
a cushion comprising an open cell foam and adapted to be adjacent the ear of the user;
an inner cushion cover substantially covering the inner portion of the cushion adjacent to the ear of the user; the inner cushion cover comprising a plurality of openings, and
an outer cushion cover substantially covering the outer part of the cushion away from the ear of the user, the outer cushion cover comprising a first layer having an average area density less than about 0.03 g/cm 2 and a second layer attached to the first layer, the second layer having an average area density greater than the average area of the first layer and greater than about 0.045 g/cm 2 .