Device for improving sound quality

Abstract

A sheath 20 for attachment to, or integrated with, an in-ear insert having an input end 1 and an output end 2, said sheath 20 comprising a collar 24a formed of a first circumferential wall and being of truncated cone shape having a longitudinal axis and having a first end of a first diameter and a second end of a second, larger diameter, such that the circumferential wall extends at an acute angle relative to said longitudinal axis, the sheath 20 being oriented to a said ear insert such that, in use, the first end of the collar 24a is nearest the input end 1 thereof and the circumferential wall extends around a portion of the outer wall of the ear insert.

Description

[0001] DEVICE FOR IMPROVING SOUND QUALITY

[0002] Field of the Invention

[0003] This invention relates generally to a device for improving sound quality experienced by a user and, more particularly but not necessarily exclusively to a device for use with an ear insert for reducing sound distortion caused by resonance within the outer ear. The invention also relates to an ear insert including or incorporating such a device.

[0004] Background of the invention

[0005] The human ear has three distinguishable parts, namely the outer, middle and inner ear. The outer ear consists of the visible portion called the auricle or pinna, which projects from the side of the head. It is shaped to form an irregular shallow funnel, with a depression known as the concha leading directly to the entrance of the ear canal. The concha is partly covered by two small projections: the tongue-like tragus at the front and the antitragus behind. The outer curve of the auricle is known as the helix, and between the helix and the concha region, there is a further curved ridge formed of the scapha and the antihelix.

[0006] The function of the outer ear is to collect sound waves and guide them, via the ear canal, to the tympanic membrane. In effect, the outer ear acts to ‘funnel’ sound waves from a listener’s vicinity into the ear canal. However, the geometry of the outer ear, including the concha, creates interference in the sound waves by reflecting and deflecting sound waves not directly entering the ear canal but instead ‘bouncing’ around the irregular curves and surfaces of the outer ear. These reflected / deflected sound waves interfere with the sound waves travelling directly (uninterrupted) from the source into the listener’s ear canal and create resonance. This resonance, characterized by an incoherent sound wave, can be amplified in the ear canal with a gain of up to 20dB at some frequencies, and presents at the tympanic membrane as noise distortion, which can have a negative and detrimental effect on the quality of sounds, such as music, reaching the listener’s inner ear.

[0007] It is known to use an ear insert, such as that described in International Patent Application No. PCT / GB2021 / 050676 to reduce the occurrence of noise distortion created and amplified within the human ear canal. However, whilst an in-ear ear insert of this type acts to reduce resonance created within the ear canal, it cannot necessarily reduce the occurrence of resonance created by sound waves incoherently reflected / deflected into the true sound waves entering the ear canal from the irregular curves and surfaces of the parts of the outer ear.

[0008] Aspects of the present invention seek to address at least one or more of these issues.

[0009] Statements of Invention

[0010] In accordance with a first aspect of the invention, there is provided a sheath for use with an in-ear insert having an input end and an output end, said sheath comprising a collar formed of a first circumferential wall and being of truncated cone shape having a longitudinal axis and having a first end of a first diameter and a second end of a second, larger diameter, such that the circumferential wall extends at an acute angle relative to said longitudinal axis, the sheath further comprising mounting means for mounting the collar onto an ear insert such that, in use, the first end of the collar is nearest the input end thereof and the circumferential wall extends around a portion of the outer wall of the ear insert.

[0011] In an embodiment, said mounting means may comprise a sleeve member configured to, in use, fit over and around a portion of the outer wall of an in-ear ear insert.

[0012] The acute angle may be between 40 and 50 degrees., and beneficially substantially 45 degrees.

[0013] Beneficially, the outer apex between the first end of the collar and the mounting means may be slightly rounded or truncated.

[0014] In an embodiment, the mounting means and said first circumferential wall may be integrally formed.

[0015] Beneficially, at least said first circumferential wall may be formed of a resil iently flexible material, such as silicone.

[0016] In an embodiment, the collar may comprise a second circumferential wall of truncated cone shape that surrounds said first circumferential wall and has a first end of a first diameter that extends outwardly from the second end of said first circumferential wall, at an angle relative thereto, and a second end of a second, larger diameter, such that a generally V-shaped groove is defined between the first and second circumferential walls.

[0017] In this case, the angle between the first and second circumferential walls may be between 80 and 100 degrees, and beneficially substantially 90 degrees.

[0018] Beneficially, the the inner apex of said generally V-shaped groove may be slightly rounded or truncated.

[0019] The mounting means and said first and second circumferential walls may, at least in some embodiments, be integrally formed.

[0020] The collar, formed of said first and second circumferential walls, may, beneficially, be formed of a resil iently flexible material, such as silicone.

[0021] According to another aspect of the invention, there is provided an in-ear insert comprising a generally tubular body and having a sheath substantially as described above mounted thereon, affixed thereto or formed integrally therewith.

[0022] According to another aspect of the invention, there is provided an in-ear ear insert comprising a core having an outer wall and an inner wall defining a channel for guiding sound waves, in use, from a first open end thereof to a second open end, wherein the outer wall of said core defines an integra, generally frusto-conical, collar portion that extends around said first open end, the collar portion having an angled side wall that extends from said first open end, along a portion of the length of the core, to an intermediate location along the outer wall of the core, the diameter of said collar portion being smaller at said first open end than at said intermediate location.

[0023] In an embodiment, the angle of the side wall defining said collar portion may be substantially equal all the way around the collar. Alternatively, the angle of the side wall defining said collar portion may vary around said collar portion. These and other aspects of the invention will be apparent from the following detailed description.

[0024] Brief description of the Drawings

[0025] Embodiments of the present invention will now be described by way of examples only, and with reference to the accompanying drawings, in which:

[0026] Figure 1 is a schematic side cross-sectional view of a sheath according to a first exemplary embodiment of the invention;

[0027] Figure 2 is a schematic front view of the sheath of Figure 1 ;

[0028] Figure 3 is a schematic side view of the sheath of Figure 1 ;

[0029] Figure 4 is a schematic side cross-sectional view of a sheath according to a second exemplary embodiment of the invention;

[0030] Figure 5 is a schematic front view of the sheath of Figure 4;

[0031] Figure 6 is a schematic side view of the sheath of Figure 4;

[0032] Figure 7 is a schematic side view of an ear insert having mounted thereon, or incorporating, a sheath according to an exemplary embodiment of the invention;

[0033] Figure 8 is a schematic side view of an ear insert having mounted thereon, or incorporating, a sheath according to another exemplary embodiment of the invention;

[0034] Figure 9 is a schematic longitudinal cross-section of an in-ear ear insert according to an exemplary embodiment of the invention; and

[0035] Figure 10 is a schematic side view of an in-ear ear insert according to an exemplary embodiment of the invention.

[0036] Detailed Description

[0037] In the following description of various exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown, by way of examples and illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that variations and modifications may be made, without departing from the scope of the invention as defined in the appended claims. The following detailed description is therefore not to be taken in a limited sense.

[0038] The specification may refer to “an”, “one” or “some” embodiment(s) in some parts. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature applies to only one embodiment. Single features of different embodiments may also be combined to make another embodiment.

[0039] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and / or “comprising”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, operations, steps, elements, components and / or groups thereof As used herein, the term “and / or” includes any and all combinations and arrangements of one or more of the associated listed items.

[0040] Directional descriptors such as upper, lower, left, right, clockwise, anti-clockwise, front, rear and other similar adjectives are used for clarity and refer to the orientation of the invention as illustrated in the drawings, however it will be clear to those skilled in the art that the invention may not always be oriented as illustrated and the invention is not intended to be limited in this regard.

[0041] Referring to Figures 1 to 3 of the drawings, an example device or sheath 10 for improving sound quality comprises a generally tubular sleeve 12, open at both ends, and configured to fit over the input end of an ear insert (not shown in Figures 1 to 3). It is to be understood that the references herein to an ‘ear insert’ herein is intended to incorporate all in-ear waveguide devices designed to receive and guide sound waves into the user’s ear canal, and the present invention is not necessarily intended to be limited in terms of its specific design, configuration or usage. The longitudinal central axis A through the tubular sleeve 12 defines the path along which sound waves can travel, in use, from the ‘front’ end 1 to the Tear’ end 2.

[0042] The sheath 10 further comprises a collar 14 formed by a circumferential wall that extends outwardly, at an angle, from the circumferential edge of the sleeve 12 at the ‘front’ end 1 of the sheath 10, and surrounds the body of the sleeve 12, i.e. the collar 14 extends Tearwardly’, at an angle, from the ‘front’ end of the sleeve 12 to completely surround the length of the tubular sleeve 12, and the distal edge of the collar 14, at its open end, may extend longitudinally beyond the end of the sleeve 12 at the Tear’ end 2 of the sheath 10. Thus, the collar 14 is of a substantially truncated cone shape, having a first end (nearest the distal or ‘front’ end of the sleeve 12) of a first diameter, and an opposite, open end of a second, larger diameter.

[0043] The wall forming the collar 14 beneficially extends from the circumferential ‘front’ end of the sleeve 12 at an angle of substantially 45° relative to the axis A. However, in other embodiments, this angle may be between 40 and 50 degrees.

[0044] The sleeve 12 and collar 14 are beneficially integrally formed or molded, and may be formed of a resil iently flexible material such as silicone. However, this is not necessarily essential, and they may be formed of a more rigid material in some embodiments.

[0045] The outer apex 16, formed between the edge of the sleeve 12 and the collar 14, is beneficially slightly rounded and / or truncated, primarily for comfort.

[0046] Referring to Figures 4 to 6 of the drawings, another example sheath 20 comprises a generally tubular sleeve 22, open at both ends, and shaped and configured to fit over the input end of an in-ear ear insert (not shown in Figures 4 to 6 of the drawings). The central longitudinal axis A through the tubular sleeve 22 defines the path along which sound waves can travel from the ‘front’ end 1 to the Tear’ end 2 of the sheath 20.

[0047] The sheath 20 further comprises a collar 24 formed of first and second collar portions 24a, 24b. The first collar portion 24a is formed by a wall that extends outwardly at an angle from the circumferential edge of the sleeve 22 at the ‘front’ end 1 of the sheath 20, and surrounds the body of the sleeve 22, i.e. the first collar portion 24a extends Tearwardly’, at an angle, from the ‘front’ end 1 of the sleeve 22 to completely surround the length of the cylindrical sleeve 22, and the distal, open end of the collar portion 24a may extend longitudinally beyond the end of the sleeve 22 at the ‘rear’ end 2 of the sheath 20 (in a similar manner to the collar 14 in the example sheath 10 described above with reference to Figures 1 to 3 of the drawings). Thus, the first collar portion 24a is of a substantially truncated cone shape, having a first end (nearest the distal or ‘front’ end of the sleeve 22) of a first diameter, and an opposite, open end of a second, larger diameter.

[0048] The wall forming the first collar portion 24a beneficially extends from the circumferential ‘front’ end of the sleeve 22 at an angle of substantially 45° relative to the axis A. However, in other embodiments, this angle could be between 40 and 50 degrees.

[0049] The second collar portion 24b is formed of a wall that extends from the distal circumferential (open) edge of the wall forming the first collar portion 24a, at an angle relative thereto, back toward the ‘front’ end 1 of the sheath 20, such that a generally V- shaped groove 26 is defined between the outer surface of the first collar portion 24a and the inner surface of the second collar portion 24b, the opening of the groove 26 facing the ‘front’ end 1 of the sheath 20. The second collar portion 24b surrounds the length of the first collar portion 24a, and the distal circumferential (open) edge of the second collar portion 24b may, beneficially, be in-line with the plane defined laterally across the ‘front’ end of the sleeve 22.

[0050] The wall forming the second collar portion beneficially extends from the distal end of the wall forming the first collar portion 24a at an angle of substantially 90° relative to the wall forming the first collar portion 24a (i.e. the second collar portion 24b may extend from the distal end of the first collar portion 24a at an angle of substantially 45° relative thereto such that the internal angle of the apex of he generally V-shaped groove 26 may be substantially 90°). However, in other example embodiments, the internal angle of the generally V-shaped groove 26 may be between 80 and 100 degrees.

[0051] The sleeve 22 and collar 24 (formed of first and second collar portions 24a, 24b) may, beneficially, be integrally formed or molded, and may be formed of a resil iently flexible material such as silicone, although this is not necessarily essential, and the sheath 20 could be formed of a more rigid material. The outer apex between the sleeve 22 and the first collar portion 24a and the inner apex of the generally V-shaped groove 26 may, beneficially, be slightly rounded or truncated to eliminate any sharp comers, primarily for comfort.

[0052] Referring to Figure 7 of the drawings, in use, the sheath 10 according to a first example embodiment (as described above with reference to Figures 1 to 3 of the drawings) is fitted over the input (or ‘front’) end 1 of a generally tubular ear insert 30. If the sheath 10 is formed of a resiliently flexible or elastic material, such as silicone, the sleeve 12 can simply be flexed and stretched slightly to fit it over the end of the ear insert 30, and then released so that the inner surface of the sleeve 12 engages in a friction fit with the outer surface of the ear insert. However, in other example embodiments, the ear insert 30 may have the sheath 10 permanently affixed thereon or may even have the sheath integrally formed therewith.

[0053] The Tear’ or output end of the ear insert 30 may be configured to removably receive thereover a resiliently flexible tip (not shown) of the type in common usage with in-ear earphones and the like.

[0054] The sheath 10, so mounted or otherwise provided at the input end 1 of an ear insert 30, provides an angled circumferential collar 14 ‘facing’ any incoming sound waves from the user’s environment and, in use, it would typically sit within the concha region of the user’s outer ear, just in front of the tragus. Sound waves from the user’s environment will enter the user’s outer ear. Some sound waves will travel directly from the environment, substantially uninterrupted, through the opening at the ‘front’ end of the ear insert 30, into the user’s ear canal. However, other sound waves may first hit an irregular curve or surface of the user’s outer ear, and be reflected or deflected thereby. Such reflected / deflected soundwaves would then hit the angled outer surface of the collar 14 and, because of its angle relative to the axis A, will be reflected away from the opening at the ‘front’ of the ear insert 30 and away from the incoming sound, thereby preventing it from creating interference or distortion thereof.

[0055] Referring to Figure 8 of the drawings, in use, a sheath according to another example embodiment (as described above with reference to Figures 4 to 6 of the drawings) is fitted over the input (or ‘front’) end 1 of a generally tubular ear insert 30. If the sheath 20 is formed of a resiliently flexible or elastic material such as silicone, the collar 22 can simply be flexed and stretched slightly to fit over the end of the ear insert 30, and then released so that the inner surface of the sleeve 22 engages in a friction fit with the outer surface of the ear insert 30. However, in some embodiments, the ear insert 30 may have the sheath 20 permanently affixed thereto, or may even have the sheath 20 integrally formed therewith.

[0056] The Tear’ or output end of the ear insert 30 may be configured to receive thereover a resiliently flexible tip (not shown) of the type in common usage with in-ear earphones, and the like.

[0057] The sheath 20, so mounted or otherwise provided at the input end of an ear insert 30, provides a generally V-shaped circumferential groove (26, Figure 4) the open end of which is ‘facing’ any incoming sound waves from the user’s environment, and, in use, the collar 24 would typically sit within the concha region of the user’s outer ear, just in front of the tragus. Sound waves from the user’s environment will enter the user’s outer ear. Some sound waves will travel directly from the user’s environment, substantially uninterrupted, through the opening at the ‘front’ end of the ear insert 30, through the ear insert 30, to the user’s ear canal. However, other sound waves may first hit an irregular curve or surface of the user’s outer ear and be reflected and / or deflected thereby. Such reflected / deflected sound waves would then hit the angled surface (within the groove 26) of the first collar portion 24a or the angled surface (within the groove 26) of the second collar portion 24b and be reflected / deflected away from the opening in the ear insert 30 and in a direction away from the incoming sound waves, thereby preventing it from creating interference or resonance in the sound reaching the user’s tympanic membrane.

[0058] A sheath according to example embodiments of the invention thus acts to improve the sound quality experienced by a user in relation to sound from their environment. Such sound could, for example, be music at a concert, the audio of a film in a cinema, etc.

[0059] Referring to Figures 9 and 10 of the drawings, there is illustrated an example in-ear ear insert 100 in which ‘sheath’ portion is integrated into the outer wall of the core 102, adjacent a first open end 104 which sits furthest from the user’s ear canal, in use and acts as an input for sound waves. A channel extends through the core 102, and is defined by an inner side wall. The channel comprises a first, generally tubular section 106 extending from the first open end to a location part-way along the channel, and a second, generally tubular, section 108 that extends from the end of the first, generally tubular, section 106 to a second open end 110. A first longitudinal axis is defined by the ‘plane’ of the first open end 104, and the second, generally tubular, section 108 has a second longitudinal axis (defined by the direction of travel of sound waves therethrough, in use) that is substantially orthogonal to the first longitudinal axis.

[0060] Ear buds 112 may be mounted over the outer wall of the core 102, adjacent the second open end 110 (which sits nearest the user’s ear drum, in use). Accordingly, an outer ridge 114 is defined around the outer wall of the core 102, adjacent to the second open end 110, over which an ear bud 112 can be mounted and held in place.

[0061] The portion of the channel running through the second, generally tubular section 108 is slightly flared, outwardly towards the second open end 110, giving it a slightly ‘horn’ shaped profile, having a substantially circular cross-section all the way along its length of uniformly increasing diameter along at least a portion of its length.

[0062] The inner profile of the first, generally tubular, section 106 comprises a first planar wall 114 that extends from a ‘top’ portion of the first open end 104 (when the device is oriented for normal use, as illustrated in Figures 9 and 10), at an acute angle a relative to the longitudinal axis defined by the ‘plane’ of the first open end 104, to a point partway along the length of the first, generally tubular, section 106, and a second planar wall 116 that extends from that point, at an angle b of around 90° or slightly more, to the input of the second, generally tubular, section 108, terminating at a point substantially diametrically opposite the ‘bottom’ portion of the first open end 104 (when the device is oriented for normal use, as illustrated in Figures 9 and 10 of the drawings).

[0063] An inner wall section 118 extends from the ‘bottom’ portion of the first open end 104 to the input of the second, generally tubular, section 108. The inner wall section 118 comprises a short planar wall portion 120 that extends from the ‘bottom’ portion of the first open end 104, substantially parallel to the second longitudinal axis defined by the second, generally tubular, section 108 of the core 102, and an angled planar wall portion 122 that extends from the short planar wall portion 120 to the input of the second, generally tubular, section 108 of the core 102. The angled planar wall portion 122 is substantially parallel to, and longitudinally offset from, the first planar wall 114 of the first, generally tubular, section 106, such that sound waves travelling towards the user’s ear drum in a substantially straight line from the environment first hit the first planar wall 114 and are reflected laterally in the channel defined through the first, generally tubular, section 106, at substantially 90°, so that they hit the angled planar wall 122 of the inner wall section 118. The sound waves are then reflected through substantially 90° again, in the opposite direction (back towards the user’s ear drum) so that they exit the channel defined through the second, generally, tubular, section 108 in a substantially straight line. The slightly flared profile inside the second, generally tubular, section 108 helps to mitigate sound distortion.

[0064] The channel section 124 defined between the inner end of the first planar wall 114 of the first, generally tubular, section 106 and the short planar wall 120 of the inner wall section 118 extending between the first and second, generally tubular, sections 106, 108 has an angled planar wall 116, which acts to guide sound waves reflected by the first planar wall 116 onto the angled planar wall 122. In addition, any sound waves coming from the environment that do not first hit the first planar wall 116 will hit the angled planar wall 118 and be reflected back out of the channel via the first open end 104.

[0065] As a result of the configuration of the inner channel running through the core 102, the ear drum receives a substantially ‘mirror image’ of the sound received from the environment, with very little or no distortion, noise or loss of quality.

[0066] In order to mitigate resonance created by sound waves incoherently refl ected / d efl ected into the true sound waves entering the ear canal from the irregular curves and surfaces of the parts of the outer ear, the outer wall of the core 102 includes an integral ‘collar’ portion 124 adjacent the first open end 104. The collar portion 124 comprises a frusto- conical wall portion extending from the first open end 104 to a location a short way along the length of the first, generally tubular, section 106. The wall defining the collar portion 124 extends, at an acute angle (relative to the ‘plane’ defined by the first open end 104), from the open end to the larger diameter portion of the outer wall of the core 102. The angle(s) c, d of the wall defining the collar 124 may be substantially the same, but in this exemplary embodiment, the angle c of the wall defining the collar adjacent the ‘top’ portion of the first open end 104 is slightly larger, at -47°, than the angle d of the wall defining the collar adjacent the ‘bottom’ portion of the first open end 104 (which, in this exemplary embodiment, is -39°). It will be appreciated by a person skilled in the art that the angle(s) c, d could vary, according to design and manufacturing constraints, but a preferred angle range is though to be 35 - 50°. In use, sound waves from the user’s environment will enter the user’s outer ear. Some sound waves will travel directly from the user’s environment, substantially uninterrupted, through the first open end 104 of the ear insert 100. However, some sound waves may first hit an irregular curve or surface of the user’s pouter ear and be reflected and / or deflected thereby. Such reflected / deflected sound waves would then hit the angled surface of the collar portion 124 provided on the outer wall of the core 102 and be reflected / deflected away from the first open end 104 of the ear insert 100, in a direction away from the incoming sound waves, thereby preventing it from creating interference or resonance in the sound reaching the user’s tympanic membrane.

[0067] An ear insert according to exemplary embodiments of the invention, including an integral collar portion, acts to improve the sound quality experienced by a user in relation to sound from their environment. Such sound could, for example, be music at a concert, the audio of a film in a cinema, etc.

[0068] It will be apparent to a person skilled in the art, from the foregoing description, that modifications and variations can be made to the described embodiments without departing from the scope of the invention as defined by the appended claims. For example, in an example embodiment, the collar may comprise two (or even more) generally V-shaped grooves having an angle at their internal apex of between 80 and 100 degrees (e.g. substantially 90°). In an example embodiment, the sleeve may not necessarily be a continuous tubular member, but may instead, for example, comprise two diametrically opposed ‘clip’ members configured to engage, in use, with the outer surface of an ear insert. Further, in some example embodiments, the collar 14 or first collar portion 24a may not necessarily extend from the distal end of the sleeve; instead, it may extend from a location along the length of the sleeve, preferably near or adjacent to the distal ‘front’ end thereof.

Claims

CLAIMS1 . A sheath for use with an in-ear insert having an input end and an output end, said sheath comprising a collar formed of a first circumferential wall and being of truncated cone shape having a longitudinal axis and having a first end of a first diameter and a second end of a second, larger diameter, such that the circumferential wall extends at an acute angle relative to said longitudinal axis, the sheath further comprising mounting means for mounting the collar onto an ear insert such that, in use, the first end of the collar is nearest the input end thereof and the circumferential wall extends around a portion of the outer wall of the ear insert.

2. A sheath according to claim 1 , wherein said mounting means comprises a sleeve member configured to, in use, fit over and around a portion of the outer wall of an in-ear ear insert.

3. A sheath for attachment to, or integrated with, an in-ear insert having an input end and an output end, said sheath comprising a collar formed of a first circumferential wall and being of truncated cone shape having a longitudinal axis and having a first end of a first diameter and a second end of a second, larger diameter, such that the circumferential wall extends at an acute angle relative to said longitudinal axis, the sheath being oriented to a said ear insert such that, in use, the first end of the collar is nearest the input end 1 thereof and the circumferential wall extends around a portion of the outer wall of the ear insert.

4. A sheath according to any of claims 1 to 3, wherein said acute angle is between 35 and 50 degrees.

5. A sheath according to claim 4, wherein said acute angle is substantially 45 degrees.

6. A sheath according to any of the preceding claims, wherein said acute angle is substantially the same all the way around the collar.

7. A sheath according to any of claims 1 to 5, wherein said acute angle varies around the collar.

8. A sheath according to any of the preceding claims, wherein the outer apex between the first end of the collar and the mounting means is slightly rounded or truncated.

9. A sheath according to any of the preceding claims, wherein said mounting means and said first circumferential wall are integrally formed.

10. A sheath according to any of the preceding claims, wherein at least said first circumferential wall is formed of a resiliently flexible material, such as silicone.11 .A sheath according to any of the preceding claims, wherein said collar comprises a second circumferential wall of truncated cone shape that surrounds said first circumferential wall and has a first end of a first diameter that extends outwardly from the second end of said first circumferential wall, at an angle relative thereto, and a second end of a second, larger diameter, such that a generally V-shaped groove is defined between the first and second circumferential walls.

12. A sheath according to claim 11 , wherein the angle between the first and second circumferential walls is between 80 and 100 degrees.

13. A sheath according to claim 12, wherein the angle between said first and second circumferential walls is substantially 90 degrees.

14. A sheath according to any of claims 9 to 13, wherein the inner apex of said generally V-shaped groove is slightly rounded or truncated.

15. A sheath according to any of claims 9 to 14, wherein said mounting means and said first and second circumferential walls are integrally formed.

16. A sheath according to any of claims 9 to 15, wherein at least said collar, formed of said first and second circumferential walls, is formed of a resiliently flexible material, such as silicone.

17. An in-ear insert comprising a generally tubular body and having a sheath according to any of the preceding claims mounted thereon, affixed thereto or formed integrally therewith.

18. An in-ear ear insert comprising a core having an outer wall and an inner wall defining a channel for guiding sound waves, in use, from a first open end thereof to a second open end, wherein the outer wall of said core defines an integra, generally frusto-conical, collar portion that extends around said first open end,the collar portion having an angled side wall that extends from said first open end, along a portion of the length of the core, to an intermediate location along the outer wall of the core, the diameter of said collar portion being smaller at said first open end than at said intermediate location.

19. An in-ear ear insert according to claim 18, wherein the angle of the side wall defining said collar portion is substantially equal all the way around the collar.

20. An in-ear insert according to claim 18, wherein the angle of the side wall defining said collar portion varies around said collar portion.21 .An in-ear insert according to any of claims 18 to 20, wherein the angle of said side wall defining said collar portion, relative to a plane defined by said first open end, is between 35 and 50°.

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