CN108353224B

CN108353224B - Acoustic device

Info

Publication number: CN108353224B
Application number: CN201680064089.5A
Authority: CN
Inventors: R·N·利托维斯基; B·利普; J·M·吉格; C·S·威廉姆斯; P·诺维尔
Original assignee: Bose Corp
Current assignee: Bose Corp
Priority date: 2015-09-17
Filing date: 2016-09-15
Publication date: 2020-04-24
Anticipated expiration: 2036-09-15
Also published as: JP6594530B2; CN108353224A; JP2018534815A; EP3351012B1; EP3351012A1; WO2017048943A1

Abstract

An acoustic device has a neck loop constructed and arranged to be worn around a neck. The neck ring includes: a housing defining an acoustic volume; a first acoustic driver located at the first distal end of the housing and acoustically coupled to the housing; and a second acoustic driver located at a second distal end of the housing and acoustically coupled to the housing, the second distal end being opposite the first distal end.

Description

Acoustic device

Cross Reference to Related Applications

This application is a continuation-in-part application of U.S. patent application No. 14/799265 filed on day 14/7/2015, which claims the benefit of U.S. provisional patent application No. 62/026237 filed on day 18/7/2014, and is incorporated herein in its entirety by reference.

Background

The present disclosure relates to acoustic devices.

The earpiece has an acoustic driver located on, over, or in the ear. As such, they are somewhat obtrusive to wear and may inhibit the user's ability to hear ambient sounds.

Disclosure of Invention

All examples and features mentioned below may be combined in any way technically possible.

The present acoustic device directs high quality sound to each ear without an acoustic driver on, above, or in the ear. The acoustic device is designed to be worn around the neck. The acoustic device may include a neck collar having a housing. The collar may have a "horseshoe" shape or a general "U" shape with two legs located above or near the clavicle and a curved central portion located behind the neck. The acoustic device may have two acoustic drivers; one acoustic driver on each leg of the enclosure. The drivers may be located below the desired position of the user's ear with their sound axes directed towards the ear. The acoustic device may further include two waveguides within the housing, each waveguide having an outlet below the ear proximate the driver. The back side of one driver may be acoustically coupled to the inlet of one waveguide and the back side of the other driver may be acoustically coupled to the inlet of the other waveguide. Each waveguide may have: one end with a driver fed to it, under one ear (left or right); and the other end (open end) which is located under the other ear (right or left).

The waveguides may be folded on top of each other within the housing. The waveguides may be constructed and arranged such that the inlet and outlet of each waveguide are located at the top side of the housing. The waveguides may be constructed and arranged such that each waveguide has a substantially uniform cross-sectional area along its length. The waveguide may be constructed and arranged such that: each waveguide starts at the rear of one actuator, extends down the top of the housing in the adjacent leg of the neck ring to the end of the leg, turns down to the bottom of the housing and turns 180 degrees to extend back up the leg, then runs across the center and down the top of the other leg back to the outlet just behind the other actuator. Each waveguide may flip position in the central portion of the neck collar from the bottom to the top of the housing.

In one aspect, an acoustic device includes a neck loop constructed and arranged to be worn around a neck. The neck loop includes a housing including 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.

Embodiments may include one or any combination of the following features. The first and second acoustic drivers may be driven such that they radiate sound that is out of phase over at least some of the frequency spectrum. The first open-backed acoustic driver may be carried by the housing and have a first sound axis directed generally toward a desired location of one ear of the user, and the second open-backed acoustic driver may also be carried by the housing and have a second sound axis directed generally toward a desired location of the other ear of the user. The first sound outlet opening may be located proximate to the second acoustic driver, and the second sound outlet opening may be located proximate to the first acoustic driver. Each waveguide may have: an end having its corresponding acoustic driver, located at a side of the head, and proximate to and below the adjacent ear; and another end opening into its sound outlet opening, located at the other side of the head, and proximal to and below the other adjacent ear.

Embodiments may include one or any combination of the above or below features. The housing may have an outer wall, and the first and second sound outlet openings may be defined in the outer wall of the housing. The waveguide may be both defined by an outer wall of the housing and an inner wall of the housing. The inner wall of the housing may be oriented along a longitudinal axis that is twisted 180 deg. along its length. The collar may be generally "U" shaped having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define an open end of the collar, wherein the twist in the housing inner wall is located in the central portion of the collar. The inner wall of the housing may be substantially flat and located below the two sound outlet openings. The inner wall of the housing may include an elevated sound diverter below each of the sound outlet openings. The housing may have a top portion facing the ear when worn by the user, and wherein the first sound outlet opening is defined in the top portion of the housing.

Embodiments may include one or any combination of the above or below features. The housing may have: a top portion that is closest to the ear when worn by the user; and a bottom portion that is closest to the torso when worn by the user, and each waveguide may be located partially in the top portion of the housing and partially in the bottom portion of the housing. The collar may be generally "U" shaped having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define an open end of the collar. The twist in the housing inner wall may be located in a central portion of the collar. The first acoustic driver may be located in a first leg of the neck loop and the second acoustic driver may be located in a second leg of the neck loop. The first waveguide may begin below the first acoustic driver, extend along the top of the housing to the distal end of the first leg portion of the neck loop, and turn to the bottom of the housing, and extend along the first leg portion into the central portion of the neck loop where the first waveguide turns to the top of the housing and extends into the second leg portion to the first sound outlet opening. The second waveguide may begin below the second acoustic driver, extend along the top of the housing to a distal end of the second leg portion of the neck loop where the second waveguide turns to the bottom of the housing and extends along the second leg portion into a central portion of the neck loop where the second waveguide turns to the top of the housing and extends into the first leg portion to the second sound outlet opening.

In another aspect, an acoustic apparatus includes: a neck loop constructed and arranged to be worn around the neck, the neck loop including a housing including a first acoustic waveguide having a first sound outlet opening and a second acoustic waveguide having a second sound outlet opening; a first open-backed acoustic driver acoustically coupled to the first waveguide, wherein the first open-backed acoustic driver is carried by the housing and has a first acoustic axis that is directed generally toward a desired location of an ear of a user; a second open-backed acoustic driver acoustically coupled to the second waveguide, wherein the second open-backed acoustic driver is carried by the housing and has a second sound axis that is directed generally toward a desired location of the other ear of the user, wherein the first sound outlet opening is positioned proximate the second acoustic driver and the second sound outlet opening is positioned proximate the first acoustic driver, and wherein the first and second acoustic drivers are driven such that they radiate sound that is out of phase.

Embodiments may include one or any combination of the following features. The waveguide may be both defined by an outer wall of the housing and an inner wall of the housing, and wherein the inner wall of the housing is positioned along a longitudinal axis that is twisted 180 ° along its length. The collar may be generally "U" shaped having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define an open end of the collar, wherein the twist in the housing inner wall is located in the central portion of the collar. The housing may have: a top portion that is closest to the ear when worn by the user; and a bottom portion that is closest to the torso when worn by the user, and wherein each waveguide is located partially in the top portion of the housing and partially in the bottom portion of the housing.

In another aspect, an acoustic apparatus includes: a neck loop constructed and arranged to be worn around the neck, the neck loop comprising a housing including a first acoustic waveguide having a first sound outlet opening and a second acoustic waveguide having a second sound outlet opening, wherein the waveguides are both defined by an outer wall of the housing and an inner wall of the housing, and wherein the inner wall of the housing is positioned along a longitudinal axis that is twisted 180 ° along its length, wherein the neck loop is generally "U" shaped having a central portion and first and second leg portions that depend from the central portion and have distal ends that are spaced to define an open end of the neck loop, wherein the twist in the inner wall of the housing is located in the central portion of the neck loop, wherein the housing has: a top portion that is closest to the ear when worn by the user; and a bottom portion that is closest to the torso when worn by the user, and wherein each waveguide is located partially in the top portion of the housing and partially in the bottom portion of the housing. There is a first open-backed acoustic driver acoustically coupled to the first waveguide, where the first open-backed acoustic driver is located in the first leg of the neck loop and has a first sound axis directed generally toward a desired location of one of the user's ears. There is a second open-backed acoustic driver acoustically coupled to the second waveguide, where the second open-backed acoustic driver is located in the second leg of the neck loop and has a second sound axis that is directed generally toward a desired location of the other ear of the user. The first and second acoustic drivers are driven such that they radiate sound out of phase. The first sound outlet opening is positioned proximate to the second acoustic driver, and the second sound outlet opening is positioned proximate to the first acoustic driver. The first waveguide begins below the first acoustic driver, extends along the top of the housing to a distal end of the first leg portion of the neck loop where it turns to the bottom of the housing and extends along the first leg portion into a central portion of the neck loop where it turns to the top of the housing and extends into the second leg portion to the first sound outlet opening, and the second waveguide begins below the second acoustic driver, extends along the top of the housing to a distal end of the second leg portion of the neck loop where it turns to the bottom of the housing and extends along the second leg portion into the central portion of the neck loop where it turns to the top of the housing and extends into the first leg portion to the second sound outlet opening.

Drawings

Fig. 1 is a top perspective view of an acoustic device.

Fig. 2 is a top perspective view of an acoustic device worn by a user.

Fig. 3 is a right side view of the acoustic device.

Fig. 4 is a front view of the acoustic apparatus.

Fig. 5 is a rear view of the acoustic device.

Fig. 6 is a top perspective view of an interior partition or wall of a housing of an acoustic device.

Fig. 7 is a first cross-sectional view of the acoustic device, taken along line 7-7 in fig. 1.

Fig. 8 is a second cross-sectional view of the acoustic device, taken along line 8-8 in fig. 1.

Fig. 9 is a third cross-sectional view of the acoustic device, taken along line 9-9 in fig. 1.

Fig. 10 is a schematic block diagram of electronics for an acoustic device.

Fig. 11 is a graph of sound pressure levels at the ears of a dummy head with drivers of acoustic devices driven both in phase and out of phase.

Fig. 12A-12C are top perspective views of an acoustic device including various stabilizing elements worn by a user.

Detailed Description

The acoustic device directs high quality sound to the ear without direct contact with the ear and without blocking ambient sound. The acoustic device is unobtrusive and may be worn under the garment (if the garment is sufficiently acoustically transparent) or on top of the garment.

In one aspect, the acoustic device is constructed and arranged to be worn around the neck. The acoustic device has a neck loop including a housing. The neck ring has a horseshoe-like shape with two legs on the top of the torso on either side of the neck and a curved central portion behind the neck. The device has two acoustic drivers, one on each leg of the enclosure. The drivers are located below the desired position of the user's ear with their sound axes directed at the ear. The acoustic device also has two waveguides within the housing, each waveguide having an outlet below the ear, proximate the driver. The back side of one driver is acoustically coupled to the inlet of one waveguide and the back side of the other driver is acoustically coupled to the inlet of the other waveguide. Each waveguide has: one end with a driver feeding the waveguide, under one ear (left or right); and the other end (open end) which is located under the other ear (right or left).

Non-limiting examples of acoustic devices are shown in the accompanying drawings. This is but one example of many possible examples that will illustrate the subject acoustic device. The scope of the invention is not limited by the examples, but is supported by the examples.

The acoustic device 10 (fig. 1-9) includes a horseshoe-shaped (or possibly, generally "U" -shaped) neck loop 12, for example as shown in fig. 2, which is shaped, constructed and arranged so that it can be worn around a person's neck. The neck ring 12 has: a curved central portion 24 to be located at the nape of the neck "N"; and right and

left legs

20 and 22, respectively, depending from central portion 24 and constructed and arranged to be draped over the upper torso on either side of the neck, typically over or adjacent the clavicle "C". Fig. 3-5 illustrate the general form of helping the acoustic device 10 to be draped over and comfortably positioned on the neck and upper chest areas.

The neck collar 12 comprises a housing 13 which is essentially an elongated (rigid or flexible) largely hollow solid plastic tube (except for the sound inlet and outlet openings) with closed

distal portions

27 and 28. In some examples, the housing 13 is internally divided by an integrated wall (partition) 102. In one non-limiting example, two internal waveguides are defined by the outer wall of the housing and the partition 102. The housing 13 should be sufficiently rigid so that sound does not degrade significantly as it travels through the waveguide. In the present non-limiting example, where the lateral distance "D" between the

ends

27 and 28 of the right and left

neck loop legs

20 and 22 is less than the width of a typical person's neck, the neck loop also needs to be flexible enough so that the ends 27 and 28 can spread apart when the device 10 is donned and doffed, but will return to its resting shape shown in the figures. One of the many possible materials with suitable physical properties is polyurethane. Other materials may be used. Also, the device may be constructed in other ways. For example, the device housing may be made of multiple separate parts coupled together, for example, using fasteners and/or adhesives. Also, the neck ring legs need not be arranged such that they need to be spread apart when the device is placed behind the neck with the legs draped over the upper chest.

The housing 13 carries a right acoustic driver 14 and a left acoustic driver 16. The driver is located at the top surface 30 of the housing 13 and below the desired location of the ear "E". See fig. 2. The housing 13 has a lower surface 31. Because it may be desirable to orient the acoustic axis of the driver (not shown in the figures) generally at the desired location of the wearer/user's ear, the driver may be tilted or angled rearwardly (rearwardly) as shown. The drivers may point their sound axes at desired locations of the ear. Each driver may be about 10cm from the expected position of the nearest ear and about 26cm from the expected position of the other ear (this distance is measured with the flexible band running under the chin up to the farthest ear). The lateral distance between the drives is about 15.5 cm. This arrangement results in a Sound Pressure Level (SPL) from the driver that is approximately three times greater nearer the ear than the other ear, which helps to keep the channels separated.

The

waveguide outlets

40 and 50 are positioned close to and just behind the driver and in the top outer wall 30 of the housing 13. The outlet 50 is the outlet of the waveguide 110 with its inlet on the back of the right side driver 14. The outlet 40 is the outlet of the waveguide 160 with its inlet on the back of the left driver 16. See fig. 7-9. Thus, each ear receives the output directly from the front of one driver and the output from the back of the other driver. If the drivers are driven out of phase, the two acoustic signals received by each ear are in fact in phase below the fundamental waveguide quarter wave resonant frequency, which in this non-limiting example is about 130Hz to 360 Hz. This ensures that the low frequency radiation from each driver and the corresponding waveguide exit on the same side are in phase and do not cancel each other out. At the same time, the radiation from the opposite side driver and corresponding waveguide are out of phase, thereby providing far field cancellation. This reduces sound spillage from the acoustic device to others in the vicinity.

The acoustic device 10 includes a right button sheath or partial housing cover 60 and a left button sheath or partial housing cover 62; the button sheath is a sleeve that may define or support aspects of the user interface of the device, such as the volume button 68, the power button 74, the control buttons 76, and the opening 72 to expose the microphone. When present, the microphone allows the device to be used for making phone calls (like a headset). Other buttons, sliders, and similar controls may be included as desired. The user interface may be configured and positioned to permit easy operation by the user. Individual buttons may be uniquely shaped and positioned to permit identification without viewing the buttons. The electronics cover is located below the button sheath. A printed circuit board carrying the hardware necessary for the functioning of the acoustic device 10 and a battery are located below the cover.

The housing 13 includes two

waveguides

110 and 160. See fig. 7-9. Sound enters each waveguide just behind/below the driver, runs down the top side of the neck collar leg on which the driver is located, reaches the end of the leg, turns 180 °, and runs down to the bottom side of the housing at the end of the leg, and then runs back up the leg along the bottom side of the housing. The waveguide continues along a bottom side of the first portion of the central portion of the neck ring. The waveguide is then twisted so that at or near the end of the central portion of the neck ring, the waveguide returns into the top side of the housing. The waveguide ends at an outlet opening in the top of the other leg of the neck ring, near the other driver. The waveguide is formed by the space between the outer wall of the housing and the inner integrated partition or wall 102. The bulkhead 102 (shown detached from the housing in fig. 6) is a generally flat, integrated inner housing wall having a right leg 130, a left leg 138, a right end 118, a left end 140, and a central 180 deg. twist 134. The baffle 102 also has curved

angled diverters

132 and 136 that direct sound from the waveguide extending generally parallel to the housing axis, up through an outlet opening in the top wall of the housing above the diverters so that the sound is directed generally toward one of the ears.

A first portion of waveguide 110 is shown in fig. 7. The waveguide inlet 114 is located directly behind the rear portion 14a of the acoustic driver 14, and the acoustic driver 14 has a front side 14b directed to the desired location of the right ear. The downward leg 116 of the waveguide 110 is located above the bulkhead 102 and below the upper wall/top 30 of the housing. A turn 120 is defined between the end 118 of the baffle 102 and the closed, rounded end 27 of the housing 12. Waveguide 110 then continues below bulkhead 102 in an upward portion 122 of waveguide 110. The waveguide 110 then extends below the diverter that is part of the bulkhead 102 (see waveguide section 124), where the waveguide 110 is diverted to extend into the housing center section 24. Fig. 8 and 9 illustrate how two

identical waveguides

110 and 160 extend along and fold or flip over each other within the central portion of the housing so that each begins and ends in the top of the housing. This allows each waveguide to be coupled to the rear of one driver in one leg of the neck ring and have its outlet in the top of the housing in the other leg adjacent the other driver. Fig. 8 and 9 also show the second end 140 of the bulkhead 102 and the arrangement of the waveguide 160, with the waveguide 160 beginning behind the driver 16 and extending down the top of the leg 22, wherein the waveguide 160 turns to the bottom of the leg 22 and extends up the leg 22 into the center portion 24.

Waveguides

110 and 140 are essentially mirror images of each other.

In one non-limiting example, each waveguide has a generally uniform about 2cm along its entire length²The full length including a generally annular outlet opening. In one non-limiting example, each waveguide has a full length in the range of about 22cm to 44 cm; in one particular example very close to 43 cm. In one non-limiting example, the waveguide is long enough to establish resonance at about 150 Hz. More generally, the main dimensions of the acoustic device (e.g., waveguide length and cross-sectional area) are dictated primarily by ergonomics, while proper acoustic response and function are ensured by proper audio signal processing. Other waveguide arrangements, shapes, sizes, and lengths are contemplated within the scope of the present disclosure.

An illustrative but non-limiting example of electronics for an acoustic device is shown in fig. 10. In this example, the device functions as a wireless headset or different audio source that can be wirelessly coupled to a smartphone. PCB 103 carries microphone 164 and microphone processing. The antenna receives an audio signal (e.g., music) from another device. Bluetooth wireless communication protocols (and/or other wireless protocols) are supported. The user interface may, but need not, be carried as part of both PCB 103 and PCB 104. The system-on-chip generates audio signals that are amplified and provided to the L and R audio amplifiers on the PCB 104. The amplified signals are sent to left and right transducers (drivers) 16 and 14, which are open-backed acoustic drivers as described above. The acoustic driver may have a diameter of 40mm and a depth of 10mm, but need not have these dimensions. The PCB 104 also carries battery charging circuitry that interfaces with a rechargeable battery 106 that supplies all of the power for the acoustic device.

Fig. 11 illustrates SPL at one ear with the above described acoustic device. Curve 196 is in the case of an out-of-phase drive driver and curve 198 is in the case of an in-phase drive driver. Below about 150Hz, the out-of-phase SPL is higher than the in-phase drive. The benefit of out of phase driving is up to 15dB at the lowest frequency of 60-70 Hz. The same effect occurs in the frequency range from about 400Hz to about 950 Hz. The in-phase SPL is higher than the out-of-phase SPL in the frequency range of 150-400 Hz; to obtain optimum driver performance in this frequency range, the phase difference between the left and right channels should be flipped back to zero. In one non-limiting example, the phase difference between the channels is done using a so-called all-pass filter with a finite phase change slope. These provide a gradual phase change rather than an abrupt phase change which may have an adverse effect on sound reproduction. This allows the benefits of proper phase selection while ensuring power efficiency of the acoustic device. Above 1KHz, the phase difference between the left and right channels has far less effect on the SPL due to the lack of correlation between the channels at higher frequencies.

Fig. 12A-12C depict three non-limiting examples of acoustic devices 10 that also include stabilizing elements that provide additional support and retention for a user wearing the device. The stabilizing element acts to: the acoustic device 10 is held in place for use during rigorous activities such as running, jogging, skiing, mountain biking and weight training, for example.

As described above with respect to fig. 1 to 9, the acoustic device 10 in fig. 12A to 12C includes: a neck ring 12 (FIG. 1); a curved central portion 24 (fig. 1) which will be located at the nape of the neck "N" (fig. 2); and right and

left legs

20 and 22, respectively, depending from central portion 24 and constructed and arranged to drape over the upper torso on either side of the neck, generally over or near the clavicle "C" (fig. 2). The acoustic device 10 in fig. 12A to 12C includes one or more drivers (not shown). The driver may be located on or below the surface of the housing of the acoustic device 10, typically within the right and

left legs

20 and 22, respectively, and below the desired location of the ear "E" (fig. 2). As previously described, the driver may be angled to generally orient the acoustic axis of the driver at a desired location of the user's ear. Each driver may be about 10cm from the expected position of the nearest ear and about 26cm from the expected position of the other ear (this distance is measured with a flexible band extending under the chin up to the farthest ear). The lateral distance between the drives is about 15.5 cm. The acoustic device 10 of fig. 12A-12C may also include a waveguide outlet (not shown) positioned proximate to and just behind the driver along the right and

left legs

20 and 22, respectively.

Fig. 12A shows an acoustic device 10, which includes: a strap 200 attached to the acoustic device 10; and a releasable clasp 202, which together provide additional stability by permitting the user to releasably secure the device to the torso for use during rigorous activities. Fig. 12B shows an acoustic device 10 that includes a stabilizing collar 204 that is designed, sized, and configured to contact or at least partially contact the back and sides of the user's neck. The stabilizing collar 204 provides additional stability for using the acoustic device 10 during the activities described above. Fig. 12C shows an acoustic device 10 that includes an inflatable chamber 206 that imparts additional stability for use of the device 10 during the activities described above. The chamber 206 is designed, sized and configured to contact the back and sides of the user's neck. In this example, the chamber 206 may be inflated with air or other suitable gas to a pressure level that provides sufficient stability and comfort to the user. The pressure level inside the chamber 206 may be adjusted to a level suitable for a particular user or use during a particular activity. The chamber 206 may include a pressure valve (not shown) that facilitates the addition or release of air as understood by one of ordinary skill in the art. In one non-limiting example, the chamber 206 may include multiple sub-chambers or segments to impart a predefined shape or direction of pressure against the user's neck as the chamber is inflated.

The housing of the acoustic device 10 may include a skin or cover that surrounds a portion or all of the device housing. In one example, the cover includes acoustically transparent regions in those locations where the cover covers the driver and/or waveguide outlets in the right and

left legs

20, 22, respectively, of the acoustic device 10. In some examples, the cover serves to protect the acoustic device 10 from scratching or abrasion, provide additional comfort to the user while wearing the device 10, and/or may allow customization of the appearance of the device 10. The skin may be removable or permanently attached to the acoustic device 10.

The embodiments of the system and method described above include computer components and computer-implemented steps that will be apparent to those skilled in the art. For example, those skilled in the art will appreciate that the computer implemented steps may be stored as computer executable instructions on a computer readable medium such as, for example, a floppy disk, a hard disk, an optical disk, flash ROMS, non-volatile ROM, and RAM. Further, those skilled in the art will appreciate that computer executable instructions may be executed on various processors, such as, for example, microprocessors, digital signal processors, gate arrays, and the like. For ease of illustration, not every step or element of the systems and methods described above is described herein as part of a computer system, but those skilled in the art will recognize that each step or element may have a corresponding computer system or software component. Accordingly, such computer system and/or software components are implemented by describing their corresponding steps or elements (i.e., their functionality) and are within the scope of the present disclosure.

A number of embodiments have been described. However, it will be appreciated that further modifications may be made without departing from the scope of the inventive concept described herein, and therefore, other embodiments are within the scope of the appended claims.

Claims

1. An acoustic device comprising:

a neck collar constructed and arranged to be worn around at least a portion of a user's neck;

a retention member extending from the neck loop, the retention member sized and configured to contact the neck or torso of the user and stabilize the acoustic device;

a first acoustic driver;

a second acoustic driver;

a first acoustic waveguide in the neck loop and having a first sound outlet opening; and

a second acoustic waveguide in the neck collar and having a second sound outlet opening;

wherein the first acoustic driver is constructed and arranged to radiate sound into the first acoustic waveguide and out of the neck loop via the first sound outlet opening, but the first acoustic driver does not radiate sound into the second acoustic driver;

wherein the second acoustic driver is constructed and arranged to radiate sound into the second acoustic waveguide and out of the neck loop via the second sound outlet opening, but the second acoustic driver does not radiate sound into the first acoustic driver; and is

Wherein the first sound outlet opening is positioned proximate to the second acoustic driver and the second sound outlet opening is positioned proximate to the first acoustic driver.

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

3. The acoustic device of claim 1 wherein the neck loop includes a housing and the first acoustic driver is recessed within the housing and has a first acoustic axis directed to a desired location of one ear of the user and the second acoustic driver is recessed within the housing and has a second acoustic axis directed to a desired location of the other ear of the user.

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

5. The acoustic device of claim 4, wherein each waveguide has: an end having its corresponding acoustic driver, located at a side of the head, and proximate to and below an adjacent ear; and another end opening into its sound outlet opening, located at the other side of the head, and proximate to and below the other adjacent ear.

6. The acoustic device of claim 1, wherein the neck loop comprises a housing and the housing has an outer wall, the first sound outlet opening being defined in the outer wall of the housing and the second sound outlet opening being defined in the outer wall of the housing.

7. The acoustic device of claim 6, wherein the waveguide is both defined by the outer wall of the housing and an inner wall of the housing.

8. The acoustic device of claim 7, wherein the inner wall of the housing is positioned along a longitudinal axis that is twisted 180 ° along its length.

9. The acoustic device of claim 8 wherein the neck loop is "U" shaped having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define an open end of the neck loop, wherein the twist in the inner wall of the housing is located in the central portion of the neck loop.

10. The acoustic device of claim 9, wherein the inner wall of the housing is flat and located below two sound outlet openings.

11. The acoustic device of claim 10 wherein the interior wall of the housing includes an elevated sound diverter below each of the sound outlet openings.

12. The acoustic device of claim 1, wherein the neck loop comprises a housing, and the housing has: a top portion that is closest to an ear when worn by the user; and a bottom portion closest to a torso when worn by the user, and wherein each waveguide is located partially in the top portion of the housing and partially in the bottom portion of the housing.

13. The acoustic device of claim 12, wherein the neck loop is "U" shaped having a central portion and first and second leg portions depending therefrom and having distal ends spaced apart to define an open end of the neck loop, wherein the waveguide is both defined by an outer wall of the housing and an inner wall of the housing, wherein the inner wall of the housing is positioned along a longitudinal axis that is twisted along its length, and wherein the twist in the inner wall of the housing is located in the central portion of the neck loop;

wherein the first acoustic driver is located in the first leg of the neck loop and the second acoustic driver is located in the second leg of the neck loop;

wherein the first acoustic waveguide begins below the first acoustic driver, extends along the top of the housing to the distal end of the first leg of the neck loop, turns toward the bottom of the housing at the distal end of the first leg, and extends along the first leg into the central portion of the neck loop where the first acoustic waveguide turns toward the top of the housing and extends into the second leg to the first sound outlet opening; and is

Wherein the second acoustic waveguide begins below the second acoustic driver, extends along the top of the housing to the distal end of the second leg of the neck loop, turns toward the bottom of the housing at the distal end of the second leg, and extends along the second leg into the central portion of the neck loop where the second acoustic waveguide turns toward the top of the housing and extends into the first leg to the second sound outlet opening.

14. The acoustic device of claim 6, wherein the housing has a top facing the ear when worn by the user, and wherein the first sound outlet opening is defined in the top of the housing and the second sound outlet opening is defined in the top of the housing.

15. An acoustic device comprising:

a neck collar constructed and arranged to be worn around at least a portion of a user's neck, the neck collar including a housing including a first acoustic waveguide having a first sound outlet opening and a second acoustic waveguide having a second sound outlet opening;

a first open-backed acoustic driver acoustically coupled to the first acoustic waveguide, wherein the first acoustic driver is configured to radiate sound into the first acoustic waveguide but not into the second acoustic waveguide;

a second open-backed acoustic driver acoustically coupled to the second acoustic waveguide, wherein the second acoustic driver is configured to radiate sound into the second acoustic waveguide but not into the first acoustic waveguide; and

a retention member extending from the shell of the neck collar, the retention member sized and configured to contact the neck or torso of the user and stabilize the acoustic device;

wherein the first sound outlet opening is positioned proximate to the second acoustic driver and the second sound outlet opening is positioned proximate to the first acoustic driver; and is

Wherein the first and second acoustic drivers are driven such that they radiate sound that is out of phase.

16. The acoustic device of claim 15, wherein the waveguide is both defined by an outer wall of the housing and an inner wall of the housing, and wherein the inner wall of the housing is positioned along a longitudinal axis that is twisted 180 ° along its length.

17. The acoustic device of claim 16 wherein the neck loop is "U" shaped having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define an open end of the neck loop, wherein the twist in the inner wall of the housing is located in the central portion of the neck loop.

18. The acoustic device of claim 17, wherein the housing has: a top portion that is closest to an ear when worn by the user; and a bottom portion closest to a torso when worn by the user, and wherein each waveguide is located partially in the top portion of the housing and partially in the bottom portion of the housing.

19. An acoustic device comprising:

a collar constructed and arranged to be worn around the neck, the collar including a housing, the housing comprises a first acoustic waveguide having a first sound outlet opening and a second acoustic waveguide having a second sound outlet opening, wherein the waveguides are both defined by an outer wall of the housing and an inner wall of the housing, and wherein, the inner wall of the housing is positioned along a longitudinal axis that is twisted 180 degrees along its length, wherein the collar is "U" shaped having a central portion and first and second leg portions, the first leg portion and the second leg portion depending from the central portion and having distal ends spaced apart to define an open end of the collar, wherein the twist in the inner wall of the housing is located in the central portion of the collar, wherein the housing has: a top portion that is closest to an ear when worn by a user; and a bottom portion closest to a torso when worn by the user, and wherein each waveguide is located partially in the top portion of the housing and partially in the bottom portion of the housing, the neck loop further comprising a retaining member sized and configured to contact the neck of the user and further stabilize the acoustic device;

a first open-backed acoustic driver acoustically coupled to the first acoustic waveguide, wherein the first open-backed acoustic driver is located in the first leg of the neck loop and has a first sound axis directed toward a desired location of an ear of the user;

a second open-backed acoustic driver acoustically coupled to the second acoustic waveguide, wherein the second open-backed acoustic driver is located in the second leg of the neck loop and has a second sound axis directed to a desired location of the other ear of the user;

wherein the first and second acoustic drivers are driven such that they radiate sound that is out of phase;

wherein the first sound outlet opening is positioned proximate to the second acoustic driver and the second sound outlet opening is positioned proximate to the first acoustic driver;