In-the-ear porting structures for earbug

• US 20090316944A1
• Filed: 06/18/2008
• Published: 12/24/2009
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Stiehl, Kurt, Tiscareno, Victor M.
• Granted Patent: US 8,737,664 B2
• Time in Patent Office: Days
• US Class Current: 381/346
• CPC Class Codes: H04R 1/1075 Mountings of transducers in earphones or headphones
• CPC Class Codes: H04R 1/2896 for loudspeaker transducers

Abstract

Systems, apparatus and methods are discussed for controlling resonance in in-the-ear headphones. Resonance effects resulting from wave reflection and superposition can occur in the cavity formed by the port tube of an earbud and the wearer'"'"'s ear canal. In this invention, acoustically resistive structures are provided to create sound diffusion in the cavity. In one embodiment, a spring coil with several adjustable parameters is inserted into the port tube. In another embodiment, a pattern of grooves is carved into the inner surface of the port tube. Porous filters can also be used in conjunction with both of the embodiments described above. The result of providing the resistive structures in an earbud is a flattened cavity frequency response and improved sound quality.

Claims

1. An in-ear-canal headphone comprising:

at least one transducer;

an air chamber with a first opening and a second opening, wherein the first opening is configured to allow air flow between the air chamber and the at least one transducer, and the second opening is configured to allow air flow between the air chamber and a wearer'"'"'s ear canal; and

at least one acoustically resistive structure, located in the air chamber, configured to control resonance in the air chamber and in the ear canal.

2. The headphone of claim 1, wherein the at least one acoustically resistive structure causes sound diffusion in the air chamber.

3. The headphone of claim 1, wherein the second opening of the air chamber is coupled to the walls of the ear canal by a substantially air tight seal.

4. The headphone of claim 3, wherein the seal is constructed from silicone.

5. The headphone of claim 3, wherein the seal is constructed from foam.

6. The headphone of claim 3, wherein the air chamber and the ear canal form a sound isolating cavity.

7. The headphone of claim 6, wherein the at least one acoustically resistive structure acts to flatten out the frequency response of the cavity.

8. The headphone of claim 7, wherein the at least one acoustically resistive structure comprises:

a spring coil inserted into the air chamber.

9. The headphone of claim 8, wherein the spring coil has a spring tension which affects the frequency response of the cavity.

10. The headphone of claim 8, wherein the spring coil has a number of turns which affects the frequency response of the cavity.

11. The headphone of claim 8, wherein the spring coil has a cross-sectional shape which affects the frequency response of the cavity.

12. The headphone of claim 11, wherein the cross-sectional shape is circular.

13. The headphone of claim 11, wherein the cross-sectional shape is rectangular.

14. The headphone of claim 7, wherein the at least one acoustically resistive structure comprises:

a pattern of grooves carved into an inner surface of the air chamber.

15. The headphone of claim 14, wherein the pattern of grooves comprises:

a spiral screw thread.

16. The headphone of claim 14, wherein the grooves have an indentation shape, and wherein the indentation shape is semi-circular.

17. The headphone of claim 14, wherein the grooves have an indentation shape, and wherein the indentation shape is triangular.

18. The headphone of claim 14, wherein the grooves have an indentation shape, and wherein the indentation shape is trapezoidal.

19. The headphone of claim 1, wherein the at least one transducer comprises:

a woofer or a tweeter.

20. The headphone of claim 1, wherein the air chamber is cylindrical in shape.

21. The headphone of claim 1, wherein the air chamber is constructed from aluminum.

22. The headphone of claim 1, wherein the air chamber is removable from the headphone.

23. The headphone of claim 1, wherein the air chamber further comprises:

at least one porous filter across the cross-section of the chamber.

24. A method for controlling resonance in an in-ear-canal headphone comprising:

generating sound waves by utilizing at least one transducer;

directing the sound waves from the at least one transducer to a wearer'"'"'s ear canal through an air chamber having a first opening and a second opening, wherein the first opening is configured to allow air flow between the air chamber and the at least one transducer, and the second opening is configured to allow air flow between the air chamber and the ear canal;

diffusing the sound waves by utilizing at least one acoustically resistive structure in the air chamber; and

controlling resonance of the sound waves in the air chamber and in the ear canal.

25. The method of claim 24, wherein the second opening of the air chamber is coupled to the walls of the ear canal by a substantially air tight seal.

26. The method of claim 25, wherein the air chamber and the ear canal form a sound isolating cavity.

27. The method of claim 26, wherein controlling the resonance comprises:

flattening the frequency response of the cavity.

28. The method of claim 24, wherein generating sound waves comprises:

generating low frequency sound waves using a woofer; and

generating high frequency sound waves using a tweeter.

29. An in-ear-canal headphone for use with a portable media device, comprising:

at least one transducer;

an air chamber with a first opening and a second opening, wherein the first opening is configured to allow air flow between the air chamber and the at least one transducer, and the second opening is configured to allow air flow between the air chamber and a wearer'"'"'s ear canal; and

at least one acoustically resistive structure, located in the air chamber, configured to control resonance in the air chamber and in the ear canal.