JP2019515590A - Sound equipment - Google Patents

Abstract

An acoustic device (12) having a neck loop (10) configured and arranged to be worn around the neck (N) of a user. The neck loop (12) comprises a first acoustic waveguide (110) having a first sound outlet aperture (50) and a second acoustic waveguide (160) having a second sound outlet aperture (40). Including a housing (13). A first open back acoustic driver (14) acoustically coupled to the first waveguide (110), and a second open back acoustic driver (acoustically coupled to the second waveguide (160) 16) exists.

Description

  The present disclosure relates to acoustic devices.

  The headset has an acoustic driver that rests on or in the ear. They may therefore be somewhat noticeable when worn and may inhibit the ability to hear the user's surroundings.

  All the following examples and features can be combined in any way that is technically possible.

  The acoustic device delivers high quality sound to each ear with no acoustic driver on or in the ear. The acoustic device is designed to be worn around the neck. The acoustic device may comprise a neck loop having a housing. The neck loop may have a "horseshoe" -like or substantially "U" shape and may have two legs resting on or near the clavicle and a curved central portion resting on the back of the neck. The acoustic device may have two acoustic drivers, one on each leg of the housing. The driver may be located below the expected position of the user's ear and has its sound axis directed to the ear. The acoustic device may further comprise two waveguides in the housing, each one having an outlet under the ear, close to the driver. The back side of one driver may be acoustically coupled to the entrance to one waveguide, and the back side of the other driver may be acoustically coupled to the entrance to the other waveguide. Each waveguide has one end with a driver that sends it under one ear (left or right) and the other end (open end) under the other ear (right or left) ).

  The waveguides can fold over each other in the housing. The waveguides may be configured and arranged such that the inlet and the outlet to each one waveguide are located on the upper side of the housing. The waveguides may be configured and arranged such that each one waveguide has a cross-sectional area that substantially matches along its length. The waveguides, each one waveguide starting just behind one driver, extend down along the top part of the housing in the adjacent leg of the neck loop to the end of the leg and fold down to the bottom part of the housing, 180 It can be constructed and arranged to fold back and extend the legs back up and then cross the central part back down the upper part of the other leg and extend to the exit just behind the other driver . Each waveguide may reverse the position from the bottom to the top of the housing within the central portion of the neck loop.

  In one aspect, the acoustic device includes a neck loop configured and arranged to be worn around the neck. The neck loop includes a housing and has 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 back acoustic driver acoustically coupled to the first waveguide and a second open back acoustic driver acoustically coupled to the second waveguide.

  Embodiments may include one of the following features, or any combination thereof. The first and second acoustic drivers may be driven such that they emit sounds of different phases over at least some of the spectra. The first open back acoustic driver may have a first sound axis held by the housing and generally directed to a predicted position of one of the user's ears, the second open back acoustic driver also It may have a second sound axis held by the housing and generally directed to the expected position 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 aperture may be located proximate to the first acoustic driver. Each waveguide is located on one side of the head close to and adjacent to the adjacent ear, with one end having a corresponding acoustic driver for each waveguide, and on the other side of the head close to the other adjacent ear And, at the bottom of the ear, another end leading to the sound outlet opening of each waveguide.

  Embodiments can include one of the features described above or below, or any combination thereof. 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 waveguides may both be defined by the outer wall of the housing and the inner wall of the housing. The inner wall of the housing can be placed along a longitudinal axis that is twisted 180 ° along its length. The neck loop is generally in the form of a "U" having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define the open end of the neck loop. In some cases, the twist in the inner housing wall is located in the central portion of the neck loop. The inner wall of the housing is substantially flat and can be placed under both sound outlet openings. The inner wall of the housing may comprise a sound diverter raised below each of the sound outlet openings. The housing may have a top facing the ear when worn by the user, and first and second outlet openings are defined in the top of the housing.

  Embodiments can include one of the features described above or below, or any combination thereof. The housing may have an upper portion closest to the ear when worn by the user, and a bottom portion closest to the barrel when worn by the user, each waveguide comprising a portion of the upper portion of the housing and a portion of the bottom portion of the housing Can be placed on The neck loop has a generally "U" shape 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. 'Can be shaped. The twist in the housing inner wall may be located in the central portion of the neck loop. The first acoustic driver may be located in the first leg portion of the neck loop and the second acoustic driver may be located in the second leg portion of the neck loop. The first waveguide starts under the first acoustic driver and extends along the upper portion of the housing to the distal end of the first leg portion of the neck loop and folds back to the bottom portion of the housing, And may extend into the central portion of the neck loop along the leg portion of the and may fold back into the upper portion of the housing and extend into the second leg portion to the first sound outlet opening. The second waveguide starts under the second acoustic driver and extends along the upper portion of the housing to the distal end of the second leg portion of the neck loop and folds back to the bottom portion of the housing, And may extend into the central portion of the neck loop along the leg portion of the and may fold back into the upper portion of the housing and extend into the first leg portion to the second sound outlet opening.

  In another aspect, an acoustic device includes a neck loop configured and arranged to be worn around a neck, the neck loop including a first acoustic waveguide having a first sound outlet aperture, and a second acoustic waveguide. A housing comprising a second acoustic waveguide having a sound outlet aperture, and a first open back acoustic driver acoustically coupled to the first waveguide, the first open back acoustic driver comprising A first open back acoustic driver, having a first acoustic axis held and generally directed to a predicted position of one of the user's ears, and a second acoustically coupled to the second waveguide. Open back acoustic driver, wherein the second open back acoustic driver is held by the housing and is a second sound axis generally directed to a predicted position of the other ear of the user A second open back acoustic driver, wherein the first sound outlet aperture is located proximate to the second acoustic driver, and the second sound outlet aperture is proximate to the first acoustic driver The first and second acoustic drivers are driven so that they emit sounds of different phases.

  Embodiments may include one of the following features, or any combination thereof. The waveguides may both be defined by the outer wall of the housing and the inner wall of the housing, the inner wall of the housing being placed along a longitudinal axis which is twisted 180 ° along its length. The neck loop is generally in the form of a "U" having a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define the open end of the neck loop. In some cases, the twist in the inner housing wall is located in the central portion of the neck loop. The housing may have an upper portion closest to the ear when worn by the user, and a bottom portion closest to the barrel when worn by the user, each waveguide comprising a portion of the upper portion of the housing and a portion of the bottom portion of the housing Placed in

  In another aspect, an acoustic device includes a neck loop configured and arranged to be worn around a neck, the neck loop including a first acoustic waveguide having a first sound outlet aperture, and a second acoustic waveguide. The housing comprises a second acoustic waveguide having a sound outlet opening, both waveguides being defined by the outer wall of the housing and the inner wall of the housing, the inner wall of the housing being twisted by 180 ° along its length And the neck loop has a central portion and first and second leg portions depending from the central portion and having distal ends spaced apart to define the open end of the neck loop. "U-shaped", the twist in the inner wall of the housing being located in the central part of the neck loop, the housing being the upper part closest to the ear when worn by the user and the trunk when worn by the user It has a closest bottom portion, each waveguide is placed on a part of the portion and the bottom portion of the housing of the upper portion of the housing. There is a first open back acoustic driver acoustically coupled to the first waveguide, the first open back acoustic driver being located in a first leg portion of the neck loop and one of the users It has a first axis of sound that is generally directed to the expected position of the ear. There is a second open back acoustic driver acoustically coupled to the second waveguide, the second open back acoustic driver being located in the second leg portion of the neck loop and the other of the user It has a second axis of sound that is generally directed to the expected position of the ear. The first and second acoustic drivers are driven such that they emit sounds of different phases. The first sound outlet opening is located proximate to the second acoustic driver, and the second sound outlet aperture is located proximate to the first acoustic driver. The first waveguide starts under the first acoustic driver and extends along the upper portion of the housing to the distal end of the first leg portion of the neck loop and folds back to the bottom portion of the housing, Extending into the central portion of the neck loop along the leg portion of the second portion and folded back into the upper portion of the housing and into the second leg portion to the first sound outlet opening, the second waveguide Starting under the two acoustic drivers and extending along the upper part of the housing to the distal end of the second leg part of the neck loop, folding back to the bottom part of the housing, the neck loop along the second leg part Extends into the upper portion of the housing and extends into the first leg portion to the second sound outlet opening.

  In another aspect, an acoustic device includes a neck loop configured and arranged to be worn around a neck, the neck loop including a first acoustic waveguide having a first sound outlet aperture, and a second acoustic waveguide. A second acoustic waveguide having a sound outlet aperture, a first open back acoustic driver acoustically coupled to the first waveguide, and a second open acoustically coupled to the second waveguide And a back acoustic driver. A first pressure attenuation element acoustically coupled to the first waveguide and configured and arranged to attenuate one or more acoustic resonances in the first waveguide; There is a second pressure attenuation element acoustically coupled and configured and arranged to attenuate one or more acoustic resonances in the second waveguide.

  Embodiments may include one of the following features, or any combination thereof. The first pressure damping element may be acoustically coupled to the first waveguide at a first position of pressure maximum with respect to the first wavelength to be damped, and the second pressure damping element is damped It may be acoustically coupled to the second waveguide at a second position of pressure maximum for a second wavelength. The first position may be at a distance of about one-fourth of the first wavelength from the first sound outlet aperture, and the second position is about four minutes of the second wavelength from the second sound outlet aperture. Could be at a distance of 1. The first and second pressure damping elements are a foam having at least some closed cells and a waveguide wall opening, the waveguide wall opening having a resistive structure covering or within the wall opening And at least one of a pressure drop short piece.

  Embodiments may include one of the following features, or any combination thereof. At least one of the first and second pressure damping elements may comprise a branch waveguide. The branch waveguide comprises a tube with openings at both ends, one end being located inside or directly connected to the first or second waveguide, the resistive structure being at or near the other end It can be located. The other end of the tube may be located in the first or second waveguide substantially coplanar with the sound outlet aperture of the waveguide. The tube may have a length equal to about one quarter of the wavelength of the acoustic resonance to be attenuated.

  Embodiments may include one of the following features, or any combination thereof. The first and second acoustic drivers may be driven such that they emit sounds of different phases. The first acoustic driver may have a first sound axis held by the neck loop and generally directed to a predicted position of one of the user's ears, the second acoustic driver held by the neck loop And may have a second sound axis generally directed to the expected position 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 aperture may be located proximate to the first acoustic driver. Each waveguide is located on one side of the head close to and adjacent to the adjacent ear, with one end having a corresponding acoustic driver for each waveguide, and on the other side of the head close to the other adjacent ear And, at the bottom of the ear, another end leading to the sound outlet opening of each waveguide.

  Embodiments may include one of the following features, or any combination thereof. The neck loop may have an outer wall, a first sound outlet opening may be defined in the outer wall of the neck loop, and a second sound outlet opening may be defined in the outer wall of the neck loop. The neck loop may have a top facing the ear when worn by the user, a first sound outlet opening may be defined in the top of the neck loop and a second sound outlet opening may be of the neck loop It may be defined in the top. The waveguides may both be defined by the outer wall of the neck loop and the inner wall of the neck loop.

  Embodiments may include one of the following features, or any combination thereof. The neck loop has a generally "U" shape 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. 'Can be shaped. The first acoustic driver may be located in the first leg portion of the neck loop and the second acoustic driver may be located in the second leg portion of the neck loop. The first sound outlet opening may be located in the second leg portion and the second sound outlet opening may be located in the first leg portion. The acoustic device may further comprise a low resistance shield located in the waveguide between the rear of the transducer and the sound outlet aperture. The shield may be located immediately after the transducer. The neck loop may further comprise an acoustic volume between the waveguide and the rear of the transducer, and the pressure damping element may be acoustically coupled to the acoustic volume.

  In yet another aspect, an acoustic device includes a neck loop configured and arranged to be worn around a neck, the neck loop including a first acoustic waveguide having a first sound outlet aperture, and a second acoustic waveguide. A second acoustic waveguide having a sound outlet aperture, the first and second waveguides being aligned with at least a portion of the neck loop. There is a first open back acoustic driver acoustically coupled to the first waveguide and a second open back acoustic driver acoustically coupled to the second waveguide. Each waveguide has a first end and its corresponding acoustic driver located under the adjacent ear on one side of the head, each waveguide on the other side of the head on the other adjacent ear The lower end has a second end leading to its sound outlet opening. A first pressure attenuation element acoustically coupled to the first waveguide and configured and arranged to attenuate one or more acoustic resonances in the first waveguide; There is a second pressure attenuation element acoustically coupled and configured and arranged to attenuate one or more acoustic resonances in the second waveguide.

  Embodiments may include one of the following features, or any combination thereof. The waveguides may both be at least partially defined by the outer wall of the neck loop and the inner wall of the neck loop. The first and second pressure damping elements are each a foam having at least some closed cells, and a waveguide wall opening, the waveguide wall having a resistive structure covering or within the wall opening. At least one of an opening and a branch waveguide.

It is a perspective view from the top of an acoustic device. FIG. 7 is a top perspective view of an acoustic device being worn by a user. It is a right view of an acoustic device. It is a front view of an acoustic device. It is a rear view of an acoustic device. FIG. 5 is a perspective view from above of the internal partition or wall of the housing of the acoustic device. FIG. 7 is a first cross-sectional view of the acoustic device taken along line 7-7 of FIG. 1; 8 is a second cross-sectional view of the acoustic device taken along line 8-8 of FIG. 1; FIG. 9 is a third cross-sectional view of the acoustic device taken along line 9-9 of FIG. 1; It is a schematic block diagram of the electronic device for acoustic devices. FIG. 7 is a plot of sound pressure levels of the dummy head's ear, wherein the driver of the acoustic device is driven with both in phase and out of phase. FIG. 1 is a very schematic illustration of an acoustic device with a loss element that suppresses unwanted resonances. FIG. 6 is an enlarged partial schematic view of the loss element. FIG. 7 illustrates sound pressure level versus frequency for an example of an acoustic device waveguide. 6 schematically illustrates an alternative type of loss element in a waveguide of an acoustic device. FIG. 7 illustrates sound pressure level versus frequency for another example of a waveguide of an acoustic device.

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

  In one aspect, the acoustic device is configured and arranged to be worn around the neck. The acoustic device has a neck loop that includes a housing. The neck loop has a horseshoe-like shape and has two legs resting on the top of the torso on either side of the neck and a curved central portion resting on the back of the neck. The device has two acoustic drivers, one on each leg of the housing. The driver is located below the expected position of the user's ear, and their sound axis is directed to the ear. The acoustic device also has two waveguides in the housing, one waveguide each having an outlet under the ear, close to the driver. The back side of one driver is acoustically coupled to the entrance to one waveguide, and the back side of the other driver is acoustically coupled to the entrance to the other waveguide. Each waveguide has one end with a driver that sends it under one ear (left or right) and the other end (open end) under the other ear (right or left) ).

  One non-limiting example of an acoustic device is shown in the drawings. However, this is one of many possible examples that illustrate the subject sound device. The scope of the invention is not limited to this example but is supported by this example.

  The acoustic device 10 (FIGS. 1-9) may be a horseshoe shape (or, alternatively, substantially “shaped” or otherwise configured, configured and arranged to be worn around the neck of a person, as shown in FIG. U-shaped) neck loop 12 is included. The neck loop 12 depends from the central portion 24 respectively on the curved central portion 24 which will rest on the neck of the neck "N" and on either side of the neck, generally on or near the clavicle "C" And a right leg 20 and a left leg 22 configured and arranged to be hung on the upper body. Figures 3-5 illustrate an overall form that helps the acoustic device 10 to be comfortably hung and seated on the neck and upper chest area.

  The neck loop 12 comprises a housing 13 which is an essentially elongated (rigid or flexible) mostly hollow rigid plastic tube having closed distal ends 27 and 28. The housing 13 is internally divided by an integral wall (partition wall) 102. Two internal waveguides are defined by the outer wall of the housing and the partition. The housing 13 should be sufficiently rigid so that sound does not substantially deteriorate as it travels through the waveguide. In this non-limiting example, the lateral distance "D" between the end 27 of the right neck loop leg 20 and the end 28 of the left neck loop leg 22 is less than the width of a typical human neck and the neck The loop also needs to have sufficient flexibility so that the ends 27 and 28 can be unfolded when the device 10 is removed and it will also return to its resting shape shown in the drawings. One of the many possible materials with suitable physical properties is polyurethane. Other materials may be used. Also, the device may be configured in other manners. For example, the device may consist of a plurality of separate parts, which may be connected together, for example using fasteners and / or adhesives. And, the neck loop leg need not be arranged to require the neck loop leg to be unfolded when the device is placed behind the neck with the leg hanging on the entire upper chest.

  The housing 13 holds the right acoustic driver 14 and the left acoustic driver 16. The driver is located on the top surface 30 of the housing 13 and below the expected position of the ear "E". See FIG. The housing 13 has a lower surface 31. The driver may be tipped back (rear) as shown when it may be necessary to point the driver's sound axis (not shown in the drawing) to the generally expected position of the wearer / user's ear Or can be angled. The driver may have its sound axis directed to the expected position of the ear. Each driver may be about 10 cm from the expected position of the closest ear and about 26 cm from the expected position of the other ear (this distance may extend from under the chin to under the farthest ear) Measured using flexible tape). The lateral distance between the drivers is about 15.5 cm. This arrangement results in the sound pressure level (SPL) from the driver about three times that of the other ear in the near ear, which helps maintain channel separation.

  Close to the driver, just behind the driver and in position within the top outer wall 30 of the housing 13 are waveguide outlets 40 and 50. The outlet 50 is an outlet for the waveguide 110 and has its inlet at the rear of the right driver 14. The outlet 40 is an outlet for the waveguide 160 and has its inlet at the rear of the left driver 16. See Figures 7-9. Thus, each ear receives the output from the front of one driver and the output from the rear of the other driver directly. When the driver is driven at different phases, the two acoustic signals received by each ear are substantially identical below the fundamental waveguide quarter-wave resonant frequency, which in this non-limiting example is around 130-360 Hz. It becomes a phase. This ensures that the low frequency radiation from each driver and the corresponding waveguide outlet on the same side is in phase and does not cancel each other. At the same time, the radiation from the opposite driver and the corresponding waveguide are out of phase, thus providing far-field cancellation. This reduces the sound leakage from the acoustic device to others nearby.

  The acoustic device 10 includes right and left button socks or partial housing covers 60 and 62, which are devices such as a volume button 68, a power button 74, a control button 76, and an opening 72 that exposes a microphone. 6 is a sleeve that may define or support aspects of the user interface. The microphone, when present, allows the device to be used to make a call (similar to a headset). Other buttons, sliders and similar controls may be included as desired. The user interface may be configured and positioned to allow easy manipulation by the user. Individual buttons may be uniquely shaped and positioned to allow them to be identified without visual recognition. An electronic component cover is located below the button sock. Located under the cover is a printed circuit board that holds the hardware and batteries necessary for the functioning of the acoustic device 10.

  Housing 13 includes two waveguides 110 and 160. See Figures 7-9. The sound enters the waveguides just behind / below the driver, and the driver extends down the top of the neck loop leg located at the end of the leg and folds back 180 ° at the end of the leg to the bottom side of the housing and then Extends back and up along the bottom of the housing. The waveguide is continuous along the bottom side of the first portion of the central portion of the neck loop. The waveguide is then twisted so that the waveguide returns to the top of the housing at or near the end of the central portion of the neck loop. The waveguide terminates near the other driver with an exit aperture located at the top of the other leg of the neck loop. The waveguide is formed by the space between the outer wall of the housing and the integral partition or wall 102 inside. Partition 102 (shown away from the housing in FIG. 6) is a substantially flat integral inner housing wall with right leg 130, left leg 138, right end 118, left end 140, and a central 180 ° twist 134. . The bulkhead 102 also has curved angled shunts 132 and 136, which allow sound to travel from a waveguide extending generally parallel to the housing axis to an outlet opening in the top wall of the housing above the shunt. Guide through, whereby sound is generally directed towards one ear.

  The first portion of waveguide 110 is shown in FIG. The waveguide inlet 114 is located just behind the back 14a of the acoustic driver 14 and the acoustic driver 14 has a front side 14b located towards the expected position of the right ear. The lower leg 116 of the waveguide 110 is located above the septum 102 and below the top wall / top 30 of the housing. A turnback 120 is defined between the end 118 of the septum 102 and the closed rounded end 27 of the housing 12. The waveguide 110 then continues below the partition 102 in the upper portion 122 of the waveguide 110. The waveguide 110 then extends below the shunt 133 which is part of the bulkhead 102 (see waveguide portion 124), which folds back into the central housing portion 24. FIGS. 8 and 9 show how two identical waveguides 110 and 160 extend along the central portion of the housing and each waveguide starts at the upper portion of the housing and folds back into one another to terminate It illustrates whether to reverse or to invert. This allows each waveguide to be connected to the back of one driver in one leg of the neck loop and to have its outlet in the top of the housing in the other leg near the other driver Do. FIGS. 8 and 9 also show the placement of the second end 140 of the septum 102 and the waveguide 160, wherein the waveguide 160 starts from behind the driver 16 and the waveguide 160 folds back to the bottom of the leg 22. Extends down to the top of 22 and extends legs 22 up into the central portion 24. Waveguides 110 and 140 are essentially mirror images of one another.

In one non-limiting example, each waveguide has a substantially constant cross-sectional area of about 2 cm ² along its entire length and includes a substantially annular outlet opening. In one non-limiting example, each waveguide has a total length in the range of about 22 to 44 cm, and in one particular example is very close to 43 cm. In one non-limiting example, the waveguide is long enough to establish a resonance at about 150 Hz. More generally, the main dimensions of the acoustic device (e.g. waveguide length and cross-sectional area) are mainly defined by ergonomics while the appropriate acoustic response and functionality are ensured by the appropriate audio signal treatment Ru. Other waveguide arrangements, shapes, sizes, and lengths are considered within the scope of the present disclosure.

  A representative non-limiting example of the electronic components of the acoustic device is shown in FIG. In this example, the device acts as a smartphone or a wireless headset that can be wirelessly coupled to different sound sources. The PCB 103 holds the microphone 164 and microphone processing. The antenna receives an audio signal (eg, music) from another device. Bluetooth® wireless communication protocols (and / or other wireless protocols) are supported. However, the user interface may be held as part of both PCB 103 and PCB 104, but this is not necessary. The system on chip generates an audio signal that is amplified and provided to the L and R audio amplifiers on the PCB 104. The amplified signals are sent to the left and right transducers (drivers) 16 and 14 described above as open back acoustic drivers. The acoustic driver may have a diameter of 40 mm and a depth of 10 mm, although these do not have to be. The PCB 104 also holds battery charging circuitry that connects with the rechargeable battery 106 to provide all power to the acoustic device.

  FIG. 11 illustrates the SPL of one ear with the audio device described above. Plot 196 is from drivers driven at different phases, and plot 198 is from drivers driven in phase. SPLs of different phase less than about 150 Hz are higher than those of in-phase drive. The benefit of driving with different phases is up to 15 dB at the lowest frequency of 60-70 Hz. The same effect occurs at frequencies in the range of about 400 to about 950 Hz. In the 150-400 Hz frequency range, the in-phase SPL is higher than the SPLs of different phases, and to obtain the best driver performance in this frequency range, the phase difference between the left and right channels is inverted back to zero It should. In one non-limiting example, the phase difference between the channels is realized using what is called an all-pass filter with a limited phase change slope. These provide gradual phase changes rather than phase jumps that may have deleterious effects on recording and playback. This enables the benefits of proper phase selection while ensuring the power efficiency of the acoustic device. Above 1 KHz, the phase difference between the left and right channels has a very small impact on SPL due to the lack of correlation between channels at higher frequencies.

  The waveguide of the subject acoustic device is a resonant structure. It may be beneficial to suppress one or more unwanted resonances while maintaining the resonances that enhance the acoustic performance of the acoustic device. The resonance peak can be reduced by introducing a resistive loss source into the waveguide. Resistive loss elements can reduce unwanted peaks and dips in the device output, making the device output more predictable and more efficient.

  The loss element can cause one or both of speed loss and pressure loss. Examples of velocity loss elements include, but are not limited to, resistance to air flow including open cell foam, fiberglass, wool, or any other continuous fluff, and cloth, plastic, metal, or other It includes a material that provides a resistive woven shield of material. The velocity loss element will reduce the output acoustic energy level of the waveguide to different extents over different frequencies. This can be offset by increasing the sound pressure in the waveguide, but this is not always possible. The velocity loss element alone may therefore not achieve optimal broadband waveguide performance.

  The pressure drop element is an impedance element located in the area of the waveguide at high pressure, for example the maximum pressure for resonance to be damped. The pressure drop element creates a bifurcation velocity that will help reduce the undesirable high pressure mode. Non-limiting examples of pressure loss elements include closed cell foam located in the waveguide in contact with the inner wall of the waveguide or away from the wall, and any resistive shield, mesh or similar to the velocity loss element Includes a wall opening alongside the fluff.

  In order to design an actual acoustic device that includes the suppression of unwanted resonances, loss elements should be introduced to suppress unwanted modes while minimizing their impact on the desired mode. This is by introducing a loss element in a specially selected waveguide position and / or having a desired resonant frequency, which is itself a resonant structure and located at a position where they are effective at that frequency This can be achieved by using a loss element that As discussed further below, some loss elements may achieve only one of these goals, while other loss elements may achieve both.

FIG. 12A schematically illustrates an acoustic device 220 that includes acoustic waveguides 222 and 224. Transducer 232 is located at one open end of tube 230 of waveguide 222. Pressure loss element 236 is located to the wavelength of 1 from the other end 234 of the tube 230 about a quarter (lambda _1/4) distance (in frequency to be attenuated). Transducer 242 is located at one open end of tube 240 of waveguide 224. Pressure loss element 246 is located from the other end 244 of the tube 240 in a quarter of the wavelength (lambda _2/4) distance (in frequency to be attenuated). FIG. 12B is a partial enlarged view of an example of a pressure drop element 236, which is the wall of tube 230 backed by resistive element 235 (eg, foam, fluff, shield, and / or mesh) It is realized by the opening 233 in 231. The resistive element 235 may alternatively be located in the opening 233 or on the inside of the wall 231 covering the opening 233. In an additional alternative configuration, pressure drop element 236 or 246 may comprise a material that is wholly or partially aligned with the inner surface of the waveguide.

  FIG. 13 illustrates output sound pressure level (SPL) (in dB) versus frequency for an example of waveguide 222. The radiation from the front of the transducer 232 is illustrated by curve A and the radiation from the waveguide open end 234 is illustrated by curve B. Curves A and B illustrate the output without a pressure drop element, while curves A 'and B' respectively illustrate the output with pressure drop element 236 of FIG. 12A.

  The waveguide output (curve B) has multiple resonances at frequencies above 700 Hz. In order to attenuate the 1300 Hz resonance (highest peak), the pressure drop element 236 needs to be located about 6.5 cm from the waveguide open end 234 (6.5 cm is about 27 cm 1300 Hz wavelength in air Corresponding to about 1/4). The resistance (impedance) value of the loss element 236 is selected to have a maximum suppression 1300 Hz mode with acceptable loss at other frequencies (contained within the material of the pressure loss element and / or the pressure loss element Through any aperture size). The desired resistance value is one that reduces the pressure peak with minimal impact on other waveguide modes. The value of the resistance depends at least in part on the waveguide geometry and voice system design requirements, and may be determined either empirically or by voice system simulation.

  In the example illustrated in FIG. 13, the 1300 Hz mode is suppressed by more than 25 dB with only a loss of about 1 dB at 100 Hz. This result is a direct consequence of the selective spatial position of the loss resistance. Another benefit of the pressure drop element is that all standing waves that produce pressure peaks at the pressure drop element 236 are also suppressed. In this example, suppression is seen at 700 Hz and 2 KHz. In order to suppress other resonance frequencies (such as those of about 2.5 KHz), one or more additional pressure drop elements may be placed at the pressure maximum for each frequency. Similar results (not illustrated in FIG. 13) are provided to waveform 224. In one non-limiting example, three or four pressure drop elements may be used.

  It should be noted that the pressure drop element will have an effect when placed in the high pressure position, but it need not be at the maximum pressure position. Also, the element may be placed at a pressure maximum closer to the transducer than shown in FIG. 12A, but the effect is greatest when closest to the open end of the waveguide.

  FIG. 14 schematically illustrates an example of a pressure drop element having both spatial and frequency characteristics. The pressure loss short piece 260 is an open end tube located inside the tube 252 of the waveguide 250 (having the transducer 254 at one end and the other end 256 being an opening). The short piece 260 acts as a small cross-sectional branch waveguide. The short pieces 260 are preferably located near the main waveguide open end 256, although this need not be the case.

  The short pieces 260 are configured, arranged and positioned to produce a low z impedance at the resonance frequency being suppressed. The opening 262 is located at a pressure maximum at about the resonance frequency. The short piece 260 preferably has an outlet (ie, is acoustically coupled) in the main waveguide 252, but the outlet may be either inside or outside of the waveguide 252. The other end 264 of the short strip 260 is fitted with a resistance (speed) (e.g. a resistive element 266 which may be foam, wire mesh, cloth mesh, shield and / or fluff in one non-limiting example). The value of the resistance attached to the short strip 260 is selected such that the bandwidth of the short strip 260 at its minimum impedance is approximately equal to or slightly wider than the bandwidth of the waveguide peak.

  When the short pieces 260 are aligned parallel to the main waveguide 252 as illustrated in FIG. 14, both waveguides may have their open ends in the same plane 268. In this case, the length of the short pieces 260 will be equal to about 1/4 (lambda / 4) of the wavelength of the sound at the frequency to be suppressed. The area of the short pieces 260 is typically much smaller than the surface century of the main waveguide 252, and is typically about 5-10% or less in practice. The short piece 260 may be composed of a suitable plastic material, which may be the same material from which the main waveguide 252 was made, or any other suitable material.

  FIG. 14 also illustrates an optional pressure drop element 257 in the volume 255 behind the transducer 254. Volume 255 is acoustically coupled to main waveguide 252. Element 257, in this non-limiting example, may comprise an opening in the wall of volume 255, similar to pressure drop element 236 of FIG. 12B, and backed by a resistive element. The pressure drop element 257 is alternatively in the manner described elsewhere herein, such as a closed cell foam located in the volume 255 in contact with or away from the inner wall of the volume 255 It can be realized. The pressure loss element 257 will reduce the acoustic pressure driving the waveguide 252 and thus affect all modes. The pressure drop element 257 may be effective to lower the resonance peak by a first amount (e.g., about 3 dB) and to reduce the lower frequency by a smaller amount (e.g., about 1 dB). The element 257 can be used, for example, when it is difficult to arrange the loss element in or on the main waveguide.

  FIG. 15 illustrates the output SPL (dB) versus frequency for one example of the waveguide 250 of FIG. The radiation from the front of the transducer 254 is illustrated by curve A, and the radiation from the waveguide open end 256 is illustrated by curve B. Curves A and B illustrate the output without pressure drop short / branch waveguide 260. Curve B 'illustrates the output from an open end 256 having a pressure drop short / branch waveguide 260.

  In this example, the short piece has a length of about 6.5 cm (which is about one-fourth the wavelength of the sound of 1300 Hz) with its opening located in the main waveguide about 6.5 cm from the open waveguide end. Have. The undesirable peak at about 1300 Hz was suppressed by about 15 dB, while most of the other resonances remained substantially uninterfered. Thus, a pressure drop element having both space and frequency characteristics, such as that shown in FIG. 14, may be used when a single undesired resonance mode needs to be suppressed.

  The acoustic device comprises one or more of such pressure loss elements or double loss elements (i.e. pressure loss elements having both space and frequency characteristics) to improve the acoustic performance, or one or more of the waveguides. May be included in both.

  One potential problem with the present acoustic device is having two openings in the housing, one at the end of each waveguide. Sand, mud and other particles may enter through these openings. These particles can interfere with the operation of the acoustic device. For example, the particles may be packed in the small gap between the voice coil and the magnet, which may be as small as about 0.3 mm. The proper operation of the transducer can therefore be harmed by extraneous particles. Particles can be inhibited from reaching the transducer by use of a low resistance shield (acting as a velocity loss element) anywhere between the back of the transducer and the waveguide aperture. In order to suppress SPL losses from such a loss of speed element, the shield should be located at the lowest velocity point, or at least at a low volume velocity. One possible position is immediately after the low velocity transducer, as illustrated by the shield 272 in FIG. The shield preferably has an opening smaller than the gap between the voice coil of the transducer being protected and the magnet.

  Embodiments of the systems and methods described above comprise computer components and computer implemented steps, which will be apparent to those skilled in the art. For example, it will be understood by those skilled in the art that computer implemented steps may be stored as computer executable instructions on a computer readable medium, such as, for example, floppy disks, hard disks, optical disks, flash ROMs, non-volatile ROMs, and RAMs. It should be. Further, it should be understood by one skilled in the art that computer executable instructions may be executed on various processors, such as, for example, microprocessors, digital signal processors, gate arrays, and the like. Although all steps or elements of the systems and methods described above are not described herein as part of a computer system for ease of explanation, one skilled in the art would appreciate that each step or element corresponds. It will be understood that it may have a computer system or software components. Such computer systems and / or software components are therefore enabled by describing their corresponding steps or elements (ie their functions) and are within the scope of the present disclosure.

  Several implementations are described. Nevertheless, it will be understood that additional modifications can be made without departing from the scope of the inventive concept described herein, and thus other embodiments are within the scope of the claims. It will

Claims (23)

A neck loop constructed and arranged to be worn around the neck, comprising: a first acoustic waveguide having a first sound outlet opening; and a second acoustic waveguide having a second sound outlet opening Equipped with a neck loop,
A first open back acoustic driver acoustically coupled to the first waveguide;
A second open back acoustic driver acoustically coupled to the second waveguide;
A first pressure damping element acoustically coupled to the first waveguide, configured and arranged to damp one or more acoustic resonances in the first waveguide, 1 pressure damping element,
A second pressure attenuation element acoustically coupled to the second waveguide, configured and arranged to attenuate one or more acoustic resonances in the second waveguide; An acoustic device comprising two pressure damping elements.   The first pressure damping element is acoustically coupled to the first waveguide at a first position of pressure maximum relative to a first wavelength to be damped, and the second pressure damping element is damping The acoustic device of claim 1, wherein the acoustic device is acoustically coupled to the second waveguide at a second position of pressure maximum for the second wavelength being transmitted.   The first position is at a distance of about one-fourth of the first wavelength from the first sound outlet aperture, and the second position is from the second sound outlet aperture. The acoustic device of claim 2, wherein the distance is about one-fourth the wavelength.   The first and second pressure damping elements are a foam having at least some closed cells, and a waveguide wall opening, the waveguide having a resistive structure covering or within the wall opening. The acoustic device according to claim 1, comprising at least one of a wall opening and a pressure drop short piece.   The acoustic device according to claim 1, wherein at least one of the first and second pressure damping elements comprises a branching waveguide.   The branch waveguide comprises a tube with openings at both ends, one end being located inside or directly connected to the first or second waveguide, the resistive structure being at or near the other end An acoustic device according to claim 5, wherein the acoustic device is located.   The acoustic device according to claim 6, wherein the other end of the tube is located in the first or second waveguide substantially coplanar with the sound outlet opening of the waveguide.   The acoustic device of claim 7, wherein the tube has a length equal to about one-quarter of the wavelength of the acoustic resonance to be attenuated.   The acoustic device according to claim 1, wherein the first and second acoustic drivers are driven such that they emit sounds of different phases.   The first acoustic driver has a first acoustic axis carried by the neck loop and generally directed to a predicted position of one of the user's ears, the second acoustic driver comprising The acoustic device according to claim 1, having a second sound axis held by a loop and generally directed to a predicted position of the other ear of the user.   11. The device according to claim 10, wherein the first sound outlet opening is located close to the second acoustic driver and the second sound outlet opening is located close to the first acoustic driver. Sound device as described.   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. Sound device as described.   Each waveguide is located on one side of the head, close to and adjacent to the adjacent ear, with the corresponding acoustic driver of each waveguide, and on the other side of the head, close to the other adjacent ear 13. An acoustic device according to claim 12, further comprising a second end located below the ear and leading to the sound outlet opening of each waveguide.   The neck loop has an outer wall, the first sound outlet opening is defined in the outer wall of the neck loop, and the second sound outlet opening is defined in the outer wall of the neck loop An acoustic device according to claim 1.   The neck loop has a top facing the ear when worn by a user, the first sound outlet opening is defined in the top of the neck loop and the second sound outlet opening is 15. An acoustic device according to claim 14, defined in the top of the neck loop.   15. The acoustic device of claim 14, wherein the waveguides are both defined by the outer wall of the neck loop and the inner wall of the neck loop. The neck loop has 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. "U-shaped" shape,
The first acoustic driver is located in the first leg portion of the neck loop and the second acoustic driver is located in the second leg portion of the neck loop,
The acoustic device according to claim 1, wherein the first sound outlet opening is located in the second leg portion and the second sound outlet opening is located in the first leg portion. .   The acoustic device according to claim 1, further comprising a low resistance shield located in the waveguide between the rear of the transducer and the sound outlet opening.   19. An acoustic device according to claim 18, wherein the shield is located directly behind the transducer.   The acoustic device of claim 1, wherein the neck loop further comprises an acoustic volume between a waveguide and the rear of the transducer, and a pressure damping element is acoustically coupled to the acoustic volume. A neck loop constructed and arranged to be worn around the neck, the neck loop comprising a first acoustic waveguide having a first sound outlet opening and a second sound outlet having a second sound outlet opening. A neck loop, the first and second waveguides being aligned with at least a portion of the neck loop;
A first open back acoustic driver acoustically coupled to the first waveguide;
And a second open back acoustic driver acoustically coupled to the second waveguide,
Each waveguide has a first end and its corresponding acoustic driver located under the adjacent ear on one side of the head,
First and second open back acoustic drivers, each waveguide having a second end leading to its sound outlet aperture, located opposite the head and under the other adjacent ear;
A first pressure damping element acoustically coupled to the first waveguide, configured and arranged to damp one or more acoustic resonances in the first waveguide, 1 pressure damping element,
A second pressure attenuation element acoustically coupled to the second waveguide, configured and arranged to attenuate one or more acoustic resonances in the second waveguide; An acoustic device comprising two pressure damping elements.   22. The acoustic device of claim 21, wherein the waveguides are both at least partially defined by the outer wall of the neck loop and the inner wall of the neck loop.   The first and second pressure damping elements are a foam having at least some closed cells, and a waveguide wall opening, the waveguide having a resistive structure covering or within the wall opening. 22. An acoustic device according to claim 21, comprising at least one of a wall aperture and a branch waveguide.