Acoustic device

Patent metadata

Field	Value
Publication number	US-9736574-B2
Application number	US-201615150700-A
Country	US
Kind code	B2
Filing date	May 10, 2016
Priority date	Jul 18, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

An acoustic device that has a neck loop that is constructed and arranged to be worn around the neck. The neck loop includes a housing with a first acoustic waveguide having a first sound outlet opening, and a second acoustic waveguide having a second sound outlet opening. There is a first open-backed acoustic driver acoustically coupled to the first waveguide and a second open-backed acoustic driver acoustically coupled to the second waveguide.

First claim

What is claimed is:

1. An acoustic device, comprising:
a neck loop that is constructed and arranged to be worn around at least a portion of a user's neck, the neck loop comprising a generally “U”-shaped portion that comprises a central portion and first and second leg portions that depend from the central portion, the neck loop further comprising a first acoustic waveguide that extends through the central portion and has a first sound outlet opening located in the second leg, and a second acoustic waveguide that extends through the central portion and has a second sound outlet opening located in the first leg;
a first open-backed acoustic driver located in the first leg and acoustically coupled to the first waveguide, where the first driver is arranged to radiate sound outwardly from the first leg of the neck loop, and is also arranged to radiate sound into the first waveguide, through the central portion, and out the first sound outlet opening;
a second open-backed acoustic driver located in the second leg and acoustically coupled to the second waveguide, where the second driver is arranged to radiate sound outwardly from the second leg of the neck loop, and is also arranged to radiate sound into the second waveguide, through the central portion, and out the second sound outlet opening;
a first pressure damping element acoustically coupled to the first waveguide, where the first pressure damping element is constructed and arranged to damp one or more acoustic resonances in the first waveguide; and
a second pressure damping element acoustically coupled to the second waveguide, where the second pressure damping element is constructed and arranged to damp one or more acoustic resonances in the second waveguide.

2. The acoustic device of claim 1 , wherein the first pressure damping element is acoustically coupled to the first waveguide at a first location of a pressure maximum for a first wavelength to be damped, and wherein the second pressure damping element is acoustically coupled to the second waveguide at a second location of a pressure maximum for a second wavelength to be damped.

3. The acoustic device of claim 2 , wherein the first location is at a distance from the first sound outlet opening of about one-quarter of the first wavelength, and wherein the second location is at a distance from the second sound outlet opening of about one-quarter of the second wavelength.

4. The acoustic device of claim 1 , wherein the first and second pressure damping elements comprise at least one of: foam with at least some closed cells; a waveguide wall opening with a resistive structure covering or in the wall opening; and a pressure-loss stub.

5. The acoustic device of claim 1 , wherein at least one of the first and second pressure damping elements comprises a shunt waveguide.

6. The acoustic device of claim 5 , wherein the shunt waveguide comprises a tube open at both ends, with one end located inside of or directly coupled to the first or second waveguide and with a resistive structure located at or proximate the other end.

7. The acoustic device of claim 6 , wherein the other end of the tube is located in the first or second waveguide, in about the same plane as the sound outlet opening of the waveguide.

8. The acoustic device of claim 7 , wherein the tube has a length equal to about one-quarter of the wavelength of an acoustic resonance to be damped.

9. The acoustic device of claim 1 , wherein the first and second acoustic drivers are driven such that they radiate sound that is out of phase.

10. The acoustic device of claim 1 , wherein the first acoustic driver is carried by the neck loop and has a first sound axis that is pointed generally at the expected location of one ear of the user, and the second acoustic driver is carried by the neck loop and has a second sound axis that is pointed generally at the expected location of the other ear of the user.

11. The acoustic device of claim 10 , wherein the first sound outlet opening is located proximate to the second acoustic driver and the second sound outlet opening is located proximate to the first acoustic driver.

12. The acoustic device of claim 1 , wherein the first sound outlet opening is located proximate to the second acoustic driver and the second sound outlet opening is located proximate to the first acoustic driver.

13. The acoustic device of claim 12 , wherein each waveguide has one end with its corresponding acoustic driver located at one side of the head and in proximity to and below the adjacent ear, and another end that leads to its sound outlet opening, located at the other side of the head and in proximity to and below the other, adjacent ear.

14. The acoustic device of claim 1 , wherein the neck loop has an exterior wall, the first sound outlet opening is defined in the exterior wall of the neck loop, and the second sound outlet opening is defined in the exterior wall of the neck loop.

15. The acoustic device of claim 14 , wherein the neck loop has a top that faces the ears when worn by the user, and wherein the first sound outlet opening is defined in the top of the neck loop and the second sound outlet opening is defined in the top of the neck loop.

16. The acoustic device of claim 14 , wherein the waveguides are both defined by the exterior wall of the neck loop and an interior wall of the neck loop.

17. The acoustic device of claim 1 , wherein the first and second leg portions have distal ends that are spaced apart to define an open end of the neck loop.

18. The acoustic device of claim 1 , further comprising a first low resistance screen located in the first waveguide between the back of the first acoustic driver and the first sound outlet opening, and a second low resistance screen located in the second waveguide between the back of the second acoustic driver and the second sound outlet opening.

19. The acoustic device of claim 18 , wherein each screen is located directly behind the respective acoustic driver.

20. The acoustic device of claim 1 , wherein the neck loop further comprises a first acoustic volume between the first waveguide and the back of the first acoustic driver, and wherein a first pressure damping element is acoustically coupled to the first acoustic volume, and wherein the neck loop further comprises a second acoustic volume between the second waveguide and the back of the second acoustic driver, and wherein a second pressure damping element is acoustically coupled to the second acoustic volume.

21. An acoustic device, comprising:
a neck loop that is constructed and arranged to be worn around at least a portion of a user's neck, the neck loop comprising a generally “U”-shaped portion that comprises a central portion and first and second leg portions that depend from the central portion, the neck loop further comprising a first acoustic waveguide that extends through the central portion and has a first sound outlet opening located in the second leg, and a second acoustic waveguide that extends through the central portion and has a second sound outlet opening located in the first leg, wherein the first and second waveguides are side-by-side in at least some of the neck loop;
a first open-backed acoustic driver located in the first leg and acoustically coupled to the first waveguide, where the first driver is arranged to radiate sound outwardly from the first leg of the neck loop, and is also arranged to radiate sound into the first waveguide, through the central portion, and out the first sound outlet opening;
a second open-b

Assignees

• Bose Corp

Inventors

• Litovsky Roman N
• Williams Chester S

Classifications

• H04R1/2857 Primary

  for loudspeaker transducers · CPC title

• H04R1/288

  for loudspeaker transducers · CPC title

• H04R2201/023

  Transducers incorporated in garment, rucksacks or the like · CPC title

• H04R5/0335

  Earpiece support, e.g. headbands or neckrests (for monophonic headphones H04R1/105) · CPC title