WO2025093849A1

WO2025093849A1 - Ear insert

Info

Publication number: WO2025093849A1
Application number: PCT/GB2024/052057
Authority: WO
Inventors: Davies ROBERTS
Original assignee: Flare Audio Technologies Ltd
Current assignee: Flare Audio Technologies Ltd
Priority date: 2023-11-03
Filing date: 2024-08-02
Publication date: 2025-05-08
Anticipated expiration: 2026-05-03

Abstract

An ear insert (10) comprising a generally tubular core (12) having an inner wall defining a longitudinal channel for guiding sound waves, in use, from a first end (14) thereof to a second, open end (16), the inner wall defining at least a first waveguide portion (40) extending toward the second open end (16) and defining a tuning point (50) at is narrowest point, the tuning point (50) comprising an opening of diameter 3.5-3.7mm.

Description

EAR INSERT

Field of the Invention

The term ‘ear insert’ used herein is intended to encompass in-ear devices such as earphones, in-ear waveguide devices, in-ear monitors and in-ear hearing aids and devices. This invention relates generally to an ear insert that, in use, is placed in a user’s ear canal to direct sound through the ear canal toward the user’s ear drum.

Background of the Invention

Earphones are well known and in widespread use for enabling users to hear audio signals such as music or speech. In general, an in-ear earphone comprises a generally tubular housing of some type, with an acoustic driver unit at one end and an ear bud at the other end for securing the earphone within the entrance of the user’s ear canal.

It is well understood, within the field of in-ear earphone design, that there is a trade off between sound quality and the acoustic driver type (and, therefore, cost). However, all acoustic driver units are susceptible to decayed enclosure reflections that degrade the sound quality, and there are a number of earphones available now that seek to address this issue. For example, UK patent application no. GB2614033A describes an in-ear earphone having a tube that is shaped and configured to fit the user’s ear canal, and that has an inner topography shaped such that it receives sound in a straight line from the acoustic driver unit. The sound hits a first planar wall portion that acts to reflect it through 90° to a second planar wall portion. The second planar wall portion reflects the sound back through 90° and thus directs it in a straight line toward the user’s ear drum.

In-ear waveguide devices are also known and used to reduce the occurrence of noise distortion created and amplified in the human ear canal, without reducing the quality or volume of the true (undistorted) sound waves reaching the tympanic membrane of a user’s ear and, indeed, improving the sound quality experienced by the user from their environment. For example, UK patent application no. GB2593205A describes an in-ear waveguide device that has an inner tube topography defining a planar reflecting region that reflects sound received from the environment, at a defined angle, toward the user’s ear drum. Both of the solutions described above for improving sound quality experienced by the user have been found to be highly effective in reducing distortion caused by reflected sound and ensuring that as many of the pure sound waves from the source (i.e. the driver or the user’s environment) reach the user’s tympanic membrane.

However, when sound waves are reflected, they lose energy. Therefore, although these types of device operate highly effectively to reduce distortion and, therefore, improve the sound quality experienced by the user, this loss of energy caused by reflecting the sound waves to ‘funnel’ them toward the user’s ear drum will, inevitably, result in some loss of sound quality due to the associated loss of energy. Furthermore, acoustic resonance is inevitably created within the ear canal by sound waves of certain frequencies entering it.

It would, therefore, be desirable to provide an ear insert that can reduce or eliminate sound distortion caused by reflected sound waves and acoustic resonance, without loss of energy in the source sound waves, thereby further improving overall sound quality experienced by the user, and aspects of the present invention seek to address at least one or more of these issues.

Statements of Invention

Aspects and embodiments of the invention, including optional and preferred features, are defined in the appended claims.

It is to be understood that the “taper angle” used herein refers to the angle between a side wall of a waveguide portion and the longitudinal axis of the channel.

Brief Description of the Drawings

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

Figure 1 is a schematic plan view of an ear insert according to an exemplary embodiment of the invention;

Figure 2 is a schematic longitudinal cross-sectional view of the ear insert of Figure 1 ; Figure 3 is a schematic plan view of an ear insert according to another exemplary embodiment of the invention;

Figure 4 is a longitudinal cross-sectional view of the ear insert of Figure 3;

Figure 5 is an end view (from the first end of the housing) of the ear insert of Figure 3;

Figure 6 is a schematic plan view of an ear insert according to another exemplary embodiment of the invention;

Figure 7 is a longitudinal cross-sectional view of the ear insert of Figure 6, viewed from a first side;

Figure 8 is a longitudinal cross-sectional view of the ear insert of Figure 6, viewed from a second side orthogonal to said first side;

Figures 9A to 9C are schematic isometric views, from various angles, of an ear insert according to another exemplary embodiment of the invention;

Figure 9D is a schematic cross-sectional view of the ear insert of Figures 9A to 9C;

Figures 10A to 10c are schematic isometric views, from various angles, of an ear insert according to another exemplary embodiment of the invention;

Figure 10D is a schematic cross-sectional view of the ear insert of Figures 10A to 10C; and

Figure 11 is a schematic cross-sectional view of the ear insert of Figures aa1 to 11 C

Detailed Description

Referring to Figure 1 of the drawings, there is illustrated schematically, an ear insert according to an exemplary embodiment of the invention. The ear insert 10 comprises a generally tubular housing 12 having a first end 14 and an open, longitudinally opposing, second end 16. The second, open end 16 of the housing is shaped and configured to sit, in use, within a user’s ear canal, facing the tympanic membrane. Accordingly, the housing 12, at the second, open end 16 incorporates a first integral circumferential ridge portion 18 which extends outwardly, at an angle (of, for example 45° relative to the longitudinal axis of the housing 12), from the edge of the open end 16, along a short portion of the length of the housing 12, and terminates at a first curved recess 20.

The housing 12 further comprises a second circumferential ridge portion 22 approximately half way along the length of the housing 12. The second circumferential ridge portion 22 is defined by a circumferential ‘step’ 24 where the outer diameter of the housing 12 increases relative to the portion 26 of the housing extending between the first and second circumferential ridge portions 18, 22. A second curved recess 28 is defined between the first end of the second circumferential ridge portion 22 (defined by the ‘step’ 24) and the portion 26 of the housing extending between the first and second circumferential ridge portions 18, 22. The second circumferential ridge portion 22 widens gradually, at an angle (relative to the longitudinal axis of the housing 12) along a portion of the length of the housing 12 and terminates, by another ‘step’ 29, to a third curved recess 30. The outer diameter of the portion 26 of the housing 12 extending between the first and second circumferential ridge portions 18,22 gradually increases at a small angle (e.g. 2° relative to the longitudinal ais of the housing 12) from the first circumferential ridge portion 18 to the second circumferential ridge portion 22.

An integral collar 32 forms the portion of the housing exterior, immediately adjacent the first end 14, with a substantially cylindrical portion 34 of the housing 12 extending between the third curved recess 30 and the circumferential edge of the collar 32.

It will be appreciated by a person skilled in the art that the housing is beneficially moulded as a single piece, with the exterior features 18, 26, 28, 22, 30, 34, 32 formed integrally. The housing can be formed of any suitable material, such as silicone or even metal, and the present invention is not necessarily intended to be limited in this regard.

Referring now additionally to Figure 2 of the drawings, a channel 40 extends through the housing from an opening 42 at the first end 14 to an opening 44 at the second end 16. In the example illustrated, the diameter of the channel opening 42 at the first end 14 of the housing 12 is greater than the diameter of the channel opening 44 at the second end 16 of the housing 12, although this is not necessarily essential. In practice, the diameter of the channel opening 44 at the second end 16 of the housing 12 is limited by the fact that, in use, it has to pass through a portion of the user’s ear canal, and the outer diameter of the first circumferential ridge 18 (which is dependent, at least to a large extent on the diameter of the channel opening 44 at the second end 16 of the housing 12) is similarly limited and may also be dictated by the need to allow a resiliently flexible tip (not shown) to be mounted thereover for use.

In an exemplary embodiment, the diameter of the channel opening 44 at the second end 16 of the housing 12 may be substantially 4 - 5mm (e.g. substantially 4.6mm in one preferred example embodiment), but it will be appreciated by a person skilled in the art that this could be varied, and the present invention is not necessarily intended to be strictly limited in this regard. In use, a resiliently flexible tip, such as the type in common usage for in-ear earphones, can be fitted over the first circumferential ridge 18 of the housing, such that its edge engages in the first curved recess 22, thereby removably securing the tip over the second, open, end 16 of the housing 12.

The first end 14 of the housing 12 is intended, in use, to sit adjacent the user’s tragus, outside of their ear canal, such that the opening 42 at the first end 14 of the housing 12 can be of a larger diameter than that of the opening 44 at the second end 16 of the housing 12. In an exemplary embodiment of the invention, the opening 42 at the first end 14 of the housing 12 may be substantially 6 - 7mm (e.g. substantially 6.5mm in one preferred example embodiment), but it will again be appreciated by a person skilled in the art that this may be varied according to various different factors. Whilst not being limited by the inner diameter of the average user’s ear canal, there are practical limitations to the maximum diameter, including the space available between the entrance to the use’s ear canal and the tragus. However, if the overall length of the housing were such that the first end 14 protrudes further from the user’s ear canal (e.g. beyond the tragus), then the diameter of the opening 42 at the first end 14 of the housing 12 could, in theory at least, be larger. In some embodiments, where the ear insert is incorporated into an earphone, the size of the opening 42 at the first end 16 of the housing 12 may be dictated by the driver required to sit against it. Suffice it to say that the present invention is not necessarily intended to be limited in this regard.

A first waveguide portion 48 extends from the opening 42 at the first end 14 of the housing 12 to a tuning point 50 located along the length of the channel 40, and an integral second waveguide portion 52 extends from the tuning point 50 to the opening 44 at the second end 16 of the housing 12. In this example, the tuning point 50 is located substantially centrally along the length of the channel 40, such that the length of both the first and second waveguide portions 48, 52 is substantially equal. However, it will be appreciated that the tuning point 50 could be located slightly off-centre (e.g. up to substantially 3mm either side of the central point along the length of the channel 40), to allow for design criteria and limitations as well as manufacturing tolerances, without significant loss of sound quality experienced by the user.

The channel 40 is at its narrowest (i.e. has the smallest diameter) at the substantially central tuning point 50. Thus, the first waveguide portion 48 gradually widens along its length, at an angle (relative to the longitudinal axis of the channel 40), from the tuning point 50 to the opening 42 at the first end 14 of the housing 12; and the second waveguide portion 52 gradually widens long its length, at an angle (relative to the longitudinal axis of the channel 40) from the tuning point 50 to the opening 44 at the second end 16 of the housing 12. In the example illustrated, the angle between the side walls of the first waveguide portion 48 and the longitudinal axis of the channel 40 is approximately 13.5° and the angle between the side walls of the second waveguide portion 52 and the longitudinal axis of the cannel 40 is approximately 4.75°. Thus, in this specific example, the angle between any two diametrically opposed points along the wall of the first waveguide portion 48 is approximately 27°, and the angle between two diametrically opposed points along the wall of the second waveguide portion 52 is approximately 9.5°, with the length of each waveguide portion 48, 52 being substantially 6mm. However, it is important to appreciate that the embodiment illustrated, and the dimensions given above, are purely provided by way of examples. In practice, the length of each waveguide portion 48, 52 could vary between substantially 4 and 10 mm (and the overall length of the ear insert could, therefore, be substantially 8 - 20 mm) and, as stated above, they need not be precisely equal in some embodiments. The angle of the wall of the first waveguide portion 48 (relative to the longitudinal axis of the channel 40) could, in theory, be between substantially 1 and 43.5°, although in practice, at least in some embodiments, it would more practically be between substantially 22 and 32°. The angle of the wall of the second waveguide portion 52 (relative to the longitudinal axis of the channel 40) could be between substantially 1 and 7°, wherein both of these angles will ultimately be dependent on the selected diameters of the first and second openings 42, 44 and the length of the channel 40.

The inventor has discovered that by providing a channel 40, for example, incorporating a pair of integral ‘funnel-like’ waveguide portions 48, 52, end-to-end, with the narrowest point 50 located generally centrally along the length of the channel 40, between the two waveguide portions 48, 52, the narrowest point (referred to herein as “the tuning point” 50) acts to ‘tune’ the user’s ear to the sound as it reaches the tympanic membrane, thereby improving the sound quality experienced. The angled waveguide portions 48, 52 act to ensure that the sound entering the channel 40 at the opening 42 at the first end 14 of the housing 12 travels ‘smoothly’ through the channel 40 to the opening 44 at the second end 16 of the housing 12, with minimal distortion or interference by reflected sound waves.

The inventor has further discovered that, in this exemplary embodiment of the invention, the optimum location of the tuning point 50 is substantially centrally along the channel 40, between the two waveguide portions 48, 52, and that the optimum diameter of the tuning point is substantially 3.6 - 3.7 mm, although it is to be understood that variations in this diameter and the location of the tuning point 50 along the channel 40, to allow for manufacturing tolerances or to suit different configurations of the ear insert 10, are possible, with barely discernible loss of sound quality experienced by the user. Indeed, the inventor has discovered that the optimum diameter of the tuning point is 3.5-3.6mm, although it is to be understood that results very close to the optimum can be achieved using a tuning point of 3.5-3.7mm, depending on manufacturing tolerances.

Referring to Figures 3 to 5 of the drawings, there is illustrated schematically an ear insert 100 according to a second exemplary embodiment of the present invention. The ear insert 100 comprises a generally tubular housing having first end 104 and an open, longitudinally opposing, second end 106. Once again, the second end 106 is shaped and configured to sit, in use, within a user’s ear canal, facing the tympanic membrane. Accordingly, the housing 102 at the second, open end 106 incorporates a first integral circumferential ridge portion 108 which extends outwardly, at and angle (of, for example, approximately 45° relative to the longitudinal axis of the housing 102), from the edge of the open end 106, along a short portion of the exterior length of the housing 102, and terminates at a first recess 110.

The housing 102 further comprises a second circumferential ridge portion 112, approximately half way along the length of the housing 102. The second circumferential ridge portion 112 is defined by a first circumferential ‘step’ 114 where the outer diameter of the housing 102 increases relative to the portion 116 of the housing 102 extending between the first and second circumferential ridge portions 108, 112. A second, curved recess 118 is defined between the first end of the second circumferential ridge portion 112 (defined by the first ‘step’ 114) and the portion 116 of the housing extending between the first and second circumferential ridge portions 108, 112. In this embodiment, the outer diameter of the second circumferential ridge portion 112 is substantially uniform. The second, longitudinally opposing, end of the second circumferential ridge portion 112 is adjacent a second circumferential ‘step’ 118 where it meets a third circumferential ridge portion 120 of oval cross-section, the longitudinal axis of which is substantially orthogonal to the longitudinal axis of the housing 102. The outer width and length of the third circumferential ridge portion 120 increases gradually from the second end of the second circumferential ridge portion 112 to the first end 104 of the housing 102.

It will be appreciated that the housing 102 is beneficially moulded as a single piece, with the exterior features 102, 116 and 118 being formed integrally. The housing 102 can be formed of any suitable material, such as silicone or even metal, and the present invention is not necessarily intended to be limited in this regard.

Referring now specifically to Figure 4 of the drawings, a channel 124 extends through the housing from the first end 104 to the second end 106. The entrance opening 126 to the channel 124 at the first end 104 of the housing 102 is of substantially circular crosssection. Thus, an oval, substantially planar surface 129 is defined at the first end 104 of the housing 102, through which the entrance opening 126 to the channel 124 extends.

In the example illustrated, the length and width of the oval-shaped surface 129 of the third circumferential ridge portion 120 are greater than the diameter of the housing 102 at its second end 106. In practice, the diameter of the second end 106 of the housing 102 is limited by the fact that, in use, it has to pass through a portion of the user’s ear canal, and the outer diameter of the first circumferential ridge portion 108 is similarly limited, and may be dictated by the need to allow a resi liently flexible tip (not shown) to be mounted thereover for use.

In an exemplary embodiment, the diameter of the channel opening 128 at the second end 106 of the housing 102 may be substantially 4 - 5 mm (e.g. substantially 4.6 mm in one preferred example embodiment), but it will be appreciated by a person skilled in the art that this could be varied, at least by a small amount, and the present invention is not necessarily intended to be limited in this regard. In use, a resiliently flexible tip, such as the type in common usage for in-ear earphones, can be fitted over the first circumferential ridge portion 108 of the housing 102, such that its edge engages in the first recess 110, thereby removably securing the tip over the second, open, end 106 of the housing 102.

In this exemplary embodiment, the first end 104 of the housing 102 is intended, in use, to sit adjacent the user’s tragus, just outside their ear canal, such that the dimensions of the substantially oval surface 129 at the first end 104 of the housing 102 can be larger than the diameter of the housing 103 at the second end 106 and, therefore, the entrance opening 126 to the channel 124 at the first end 104 can be larger than the opening 128 at the second end 106 of the housing 102. In an exemplary embodiment of the invention, the oval surface 129 at the first end of the housing 102 may be of (outer) width 8 - 10 mm and (outer) length 12 - 14 mm. However, it will be appreciated that this is, at least in part, dependent on the diameter of the entrance opening 126 to the channel, and could be varied according to various design characteristics. It is thought that the oval surface could have a width range of substantially 4 - 14 mm and a length range of substantially 7 - 17 mm, and it will again be appreciated by a person skilled in the art that these dimensions can be varied according to various different factors, and the present invention is not necessarily intended to be limited in this regard. The oval shape of the first end 104 of the housing, and particularly the oval surface 129, which is intended to sit in the user’s ear between the front of the tragus and the entrance to the ear canal, is beneficial in that it better fits and fills the ear cavity in that region and, therefore, acts to help to prevent incoming sound from being reflected from the walls of the ear cavity and distorting the incoming sound waves. If the overall length of the ear insert were such that it extends beyond the ear cavity between the tragus and the entrance of the ear canal, in use, the outer dimensions of the third circumferential ridge portion 120 could, in theory, be larger still.

Referring particularly to Figure 5 of the drawings, the channel 124 comprises a first waveguide portion 130 that extends from the entrance opening 126 at the first end 104 of the housing 102, gradually decreasing in diameter, to a narrowest point (hereinafter referred to as the tuning point) 132 located along the length of the channel 124. In this specific example, the first waveguide portion 130 extends longitudinally through the thickness of the third circumferential ridge portion 120, gradually decreasing in diameter to the tuning point, which is located adjacent the base of the third circumferential ridge portion 120, at the second end of the second circumferential ridge portion 112.

However, this is not absolutely essential, and will be dependent on the various lengths and dimensions of the various (outer) elements of the housing 102.

An integral second waveguide portion 134 extends from the tuning point 132, gradually increasing in diameter, to the opening 128 at the second end 106 of the housing 102. In this example, the tuning point 132 is located substantially centrally along the length of the channel 124, such that the length of both the waveguide portions 130, 134 is substantially equal. However, it will be appreciated that the tuning point 132 could be located slightly off-centre in some embodiments (e.g. up to substantially 3mm either side of the central point along the length of the channel 124), to allow for design criteria and limitations, as well as manufacturing tolerances, with little discernible loss of sound quality experienced by the user.

The channel 124 is at its narrowest (i.e. has the smallest diameter) at the substantially central tuning point 132. Thus, the first waveguide portion 130 gradually widens along its length, at an angle (relative to the longitudinal axis of the channel 124) from the tuning point 132 to the entrance opening 126 at the first end 104 of the housing 102; and the second waveguide portion 134 gradually widens along its length, at an angle (relative to the longitudinal axis of the channel 124) from the tuning point 132 to the opening 128 at the second end 106 of the housing 102. In the example illustrated, the angle between the side walls of the first waveguide potion 130 and the longitudinal axis of the channel 124 is approximately 13.5° and the angle between the side walls of the second waveguide potion 134 and the longitudinal axis of the channel 124 is approximately 4.75°. Thus, in this specific example, the angle between any two diametrically opposite points along the side wall of the first waveguide portion 130 is approximately 27°, and the angle between any two diametrically opposite points along the side wall of the second waveguide portion 134 is approximately 9.5°, with the length of each waveguide portion 130, 134 being substantially equal and approximately 6 mm. However, it is important to appreciate that the embodiment illustrated and described above, and the dimensions given, are provided by way of examples in relation to one ‘optimum’ example embodiment of the invention. In practice, the length of each waveguide portion 130, 134 could vary between substantially 4 and 10 mm (and the overall length of the ear insert could, therefore, be substantially 8 - 20 mm) and, as stated above, they need not be precisely equal in some embodiments. The angle of the wall of the first waveguide portion 130 (relative to the longitudinal axis of the channel 124) could, in theory, be between 1 and 43.5°, although in practice, at least in some embodiments, it would be more likely (and practically) be between substantially 20 and 35°. The angle of the wall of the second waveguide portion 134 (relative to the longitudinal axis of the channel 124) could be between substantially 1 and 7°, wherein both of these angles will ultimately be dependent on the selected diameters of the first and second openings 126, 128 and the length of the channel (and, therefore, the lengths of the first and second waveguide portions 130, 134).

The inventor has discovered that by providing a channel 124 incorporating a pair of integral ‘funnel-like’ waveguide portions 130, 134, end-to-end, with the narrowest point 132 located generally centrally along the length of the channel 124, between the two waveguide portions 130, 134, the narrowest point (herein referred to as ‘the tuning point’ 132) acts to ‘tune’ the user’s ear to the sound as it reaches the tympanic membrane, thereby improving the sound quality experienced by a highly unexpected and surprising degree. The angles waveguide portions 130, 134 act to ensure that the sound entering the channel 124 at the opening 126 at the first end 104 of the housing 102 travels ‘smoothly’ through the channel 124 to the opening 128 at the second end 106 of the housing 102, with minimal distortion or interference by reflected sound waves. Once again, the optimum diameter of the tuning point 132 is 3.5-3.7mm, and typically more like 3.5-3.6mm.

Referring now to Figures 6 to 8 of the drawings, a third example ear insert 200 is illustrated schematically. The ear insert 200 comprises a generally tubular housing having first end 204 and an open, longitudinally opposing, second end 206. Once again, the second end 206 is shaped and configured to sit, in use, within a user’s ear canal, facing the tympanic membrane. Accordingly, the housing 202 at the second, open end 206 incorporates a first integral circumferential ridge portion 208 which extends outwardly, at and angle (of, for example, approximately 45° relative to the longitudinal axis of the housing 202), from the edge of the open end 206, along a short portion of the exterior length of the housing 202, and terminates at a first recess 210.

The housing 202 further comprises a second circumferential ridge portion 212, approximately half way along the length of the housing 202. The second circumferential ridge portion 212 is defined by a first circumferential ‘step’ 214 where the outer diameter of the housing 202 increases relative to the portion 216 of the housing 202 extending between the first and second circumferential ridge portions 208, 212. A second, curved recess 218 is defined between the first end of the second circumferential ridge portion 212 (defined by the first ‘step’ 214) and the portion 216 of the housing extending between the first and second circumferential ridge portions 208, 212. In this embodiment, the outer diameter of the second circumferential ridge portion 212 is substantially uniform. The second, longitudinally opposing, end of the second circumferential ridge portion 212 is adjacent a second circumferential ‘step’ 219 where it meets a ‘funnel’-like portion 220 of oval cross-section, the longitudinal axis of which is substantially orthogonal to the longitudinal axis of the housing 202. The outer and inner widths and lengths of the funnel-like portion 220 increase gradually from the second end of the second circumferential ridge portion 212 to the first end 204 of the housing 202. It will be appreciated that the housing 202 is beneficially moulded as a single piece, with the exterior features 208, 212 and 220 being formed integrally. The housing 202 can be formed of any suitable material, such as silicone or even metal, and the present invention is not necessarily intended to be limited in this regard.

Referring now specifically to Figures 7 and 8 of the drawings, a channel 224 extends through the housing from the first end 204 to the second end 206. The entrance opening 226 to the channel 224 at the first end 104 of the housing 102 is, in effect, the oval opening of the funnel-like portion 220 of the housing 202, and the second channel opening 228, which is of circular cross-section is at the second end 206 of the housing 202.

In the example illustrated, the length and width of the oval cross-section of the funnellike portion 220 of the housing 202 can be greater than the diameter of the housing 202 at its second end 206. In practice, the diameter of the second end 206 of the housing 202 is limited by the fact that, in use, it has to pass through a portion of the user’s ear canal, and the outer diameter of the first circumferential ridge portion 208 is similarly limited, and may be dictated by the need to allow a resi liently flexible tip (not shown) to be mounted thereover for use.

In an exemplary embodiment, the diameter of the channel opening 228 at the second end 206 of the housing 202 may be substantially 4 - 5 mm (e.g. substantially 4.6 mm in one preferred example embodiment), but it will be appreciated by a person skilled in the art that this could be varied, at least by a small amount, and the present invention is not necessarily intended to be limited in this regard. In use, a resiliently flexible tip, such as the type in common usage for in-ear earphones, can be fitted over the first circumferential ridge portion 208 of the housing 202, such that its edge engages in the first recess 210, thereby removably securing the tip over the second, open, end 206 of the housing 202.

In this exemplary embodiment, the first end 204 of the housing 202 is intended, in use, to sit adjacent the user’s tragus, just outside their ear canal, such that the dimensions of the substantially oval outer of the funnel-like portion 220 of the housing 202 can be larger than the diameter of the housing 202 at the second end 206 and, therefore, the entrance opening 226 to the channel 224 at the first end 204 can be larger than the opening 228 at the second end 206 of the housing 202. In an exemplary embodiment of the invention, the oval channel opening 226 at the first end of the housing 202 may be of (outer) width 8 - 9 mm and (outer) length 12 - 13 mm. In another exemplary embodiment, the outer width may be 11.5 - 12.5 mm and the outer length may be 15.5 - 16.5 mm. However, it will be appreciated that this could be varied according to various design characteristics. It is thought that the outer oval circumference of the funnel-like portion 220 could have a width range of substantially 4 - 14 mm and a length range of substantially 7 - 17 mm, and it will again be appreciated by a person skilled in the art that these dimensions can be varied according to various different factors, and the present invention is not necessarily intended to be limited in this regard. The oval circumferential shape of the first end 204 of the housing, which is intended to sit in the user’s ear between the front of the tragus and the entrance to the ear canal, is beneficial in that it better fits and fills the ear cavity in that region and, therefore, acts to “funnel” more sound waves into the user’s ear and help to prevent incoming sound from being reflected from the walls of the ear cavity and distorting the incoming sound waves. If the overall length of the ear insert were such that it extends beyond the ear cavity between the tragus and the entrance of the ear canal, in use, the outer dimensions of the funnel-like portion 220 could, in theory, be larger still.

Referring particularly to Figures 7 and 8 of the drawings, the channel 224 comprises a first waveguide portion 230, that is formed by the inner circumferential wall of the funnellike portion 220, extends from the entrance opening 226 at the first end 204 of the housing 202, gradually decreasing in diameter, to a narrowest point (hereinafter referred to as the tuning point) 232 located along the length of the channel 224. In this specific example, the first waveguide portion 230 extends longitudinally through the funnel-like portion 220, gradually decreasing in diameter to the tuning point, which is located adjacent the base of the third circumferential ridge portion 220, at the second end of the second circumferential ridge portion 212.

An integral second waveguide portion 234 extends from the tuning point 232, gradually increasing in diameter, to the opening 228 at the second end 206 of the housing 202. In this example, the tuning point 232 is located substantially centrally along the length of the channel 224, such that the length of both the waveguide portions 230, 234 is substantially equal. However, it will be appreciated that the tuning point 232 could be located slightly off-centre in some embodiments (e.g. up to substantially 3mm either side of the central point along the length of the channel 224), to allow for design criteria and limitations, as well as manufacturing tolerances, with little discernible loss of sound quality experienced by the user.

The channel 224 is at its narrowest (i.e. has the smallest diameter) at the substantially central tuning point 232. Thus, the first waveguide portion 230 (which has an oval cross-section) gradually widens (length-wise and width-wise) along its ‘height’, at an angle (relative to the longitudinal axis of the channel 224) from the tuning point 232 to the entrance opening 226 at the first end 204 of the housing 202; and the second waveguide portion 234 gradually widens along its length, at an angle (relative to the longitudinal axis of the channel 224) from the tuning point 232 to the opening 228 at the second end 206 of the housing 202. In the example illustrated, the angle between the side walls at the widest point of the first waveguide portion 230 and the longitudinal axis of the channel 224 is approximately 24° (see Figure 7) and the angle between the side walls at the widest part of the second waveguide potion 234 and the longitudinal axis of the channel 224 is approximately 38° (Figure 8). Thus, in this specific example, the angle between two opposite points across the width of the side wall of the first waveguide portion 230 is approximately 48° (Figure 7) and the angle between two opposite points across the length of the side wall of the second waveguide portion 234 is approximately 76° (Figure 8) with the length of each waveguide portion 230, 234 being substantially equal and approximately 6 mm. However, it is important to appreciate that the embodiment illustrated and described above, and the dimensions given, are provided by way of examples in relation to one ‘optimum’ example embodiment of the invention. In practice, the length of each waveguide portion 230, 234 could vary between substantially 4 and 10 mm (and the overall length of the ear insert could, therefore, be substantially 8 - 20 mm) and, as stated above, they need not be precisely equal in some embodiments. The angle of the wall of the first waveguide portion 230 (relative to the longitudinal axis of the channel 224) could, in theory, be between 1 and 44° (width-wise or and/or length-wise) although in practice, at least in some embodiments, it would be more likely (and practically) be between substantially 15 and 45°. The angle of the wall of the second waveguide portion 234 (relative to the longitudinal axis of the channel 224) could be between substantially 1 and 7°, wherein both of these angles will ultimately be dependent on the selected diameters of the first and second openings 226, 228 and the length of the channel (and, therefore, the lengths of the first and second waveguide portions 230, 234).

The inventor has discovered that by providing a channel 224, in this case incorporating a pair of integral ‘funnel-like’ waveguide portions 230, 234, end-to-end, with the narrowest point 232 located generally centrally along the length of the channel 224, between the two waveguide portions 230, 234, the narrowest point (herein referred to as ‘the tuning point’ 232) acts to ‘tune’ the user’s ear to the sound as it reaches the tympanic membrane, thereby improving the sound quality experienced by a highly unexpected and surprising degree. The angles waveguide portions 230, 234 act to ensure that the sound entering the channel 224 at the opening 226 at the first end 204 of the housing 202 travels ‘smoothly’ through the channel 224 to the opening 228 at the second end 206 of the housing 202, with minimal distortion or interference by reflected sound waves.

The inventor has further discovered that the optimum location of the tuning point 232 is substantially centrally along the channel 124, between the two waveguide portions 230, 234, and that the optimum diameter of the tuning point 232 is substantially 3.6 - 3.7 mm, although it is to be understood that small variations in the diameter and location of the tuning point 232, to allow for manufacturing tolerances and design limitations and requirements, are possible, with barely discernible loss of sound quality. Indeed the optimum diameter of the tuning point 232 is 3.5-3.6mm. However, it is to be understood that results very close to the optimum can be achieved with a tuning point of 3.5-3.7mm, with a small allowance for manufacturing tolerances and other slight variations.

Some embodiments of the ear insert 10, 100, 200 could be utilised for enhancing the sound quality experienced by a user in relation to sound being generated within an environment. For example, to enhance the user’s enjoyment of a music concert or cinema experience. Other embodiments of the ear insert could be incorporated into an earphone including a driver located adjacent the opening 42, 126, 226 at the first end 14, 104, 204 of the housing 10, 102, 202.

The ear insert may, in some embodiments, include a circumferential (external) sheath (not shown) located around the opening 42, 126, 226 at the first end 14, 104, 204 of the housing 12, 102, 202. The sheath may be integral with, affixed to or removably secured to the housing 12, 102, 202. The sheath acts, in use, to block and/or deflect reflected sound waves from the shell of the user’s ear such that those reflections do not enter the channel 40, 124, 224 and distort the sound waves received at the user’s tympanic membrane. The sheath may comprise a resi liently deformable or rigid ear piece that fits in the cavity between the tragus and the inner wall of user’s ear shell. The sheath may be custom made to fit precisely within a specific user’s ear cavity, or it may, for example, be formed of silicone (or other resi liently flexible material, to allow a user to ‘mould’ the ear piece to the shape of their inner ear cavity. In other embodiments, the sheath may be shaped and configured to deflect, rather than block, reflected sound waves from the ear shell defining the inner ear cavity.

In each of the embodiments described above, there is provided a pair of waveguide portions, arranged end-to-end and concentrically (in line with each other). However, arguably even better results may be achieved in embodiments where the waveguide portions are not in line with each other, but instead arranged at an angle to each other.

Accordingly, referring to Figures 9A to 9D of the drawings, an ear insert 300 according to another exemplary embodiment of the invention again comprises a generally tubular housing 302, having a first end 304 and an open, longitudinally opposing, second end 306. Once again, the second end 306 is shaped and configured to sit, in use, within a user’s ear canal, facing the tympanic membrane. Accordingly, the housing 302 at the second, open end 306 incorporates a first circumferential ridge portion 308 which extends outwardly, at an angle, from the edge of the second, open end 306, along a short portion of the exterior length of the housing 302, and terminates at a first recess 310, over which a resiliently flexible tip (not shown) may be fitted. In some embodiments, the first end 304 may be closed and fitted with a driver so as to provide an earphone. However, in the embodiment illustrated in Figure 9A to 9D, the first end 304 is also open and includes a reflector portion 312 that extends outwardly from a side edge of the open first end 304 so as to extend across the opening thereat at an angle of 45 degrees relative to the later plane.

The channel extending through the housing 300, between the first and second ends 304, 306, comprises three waveguide portions 314, 316, 318. The first waveguide portion 314 extends from the open first end 304, substantially horizontally through the housing 300 (when the device is oriented for normal use, as illustrated in Figure 9D of the drawings). A first reflective region 315 extends at an angle of 45 degrees extends between the inner end of the first waveguide portion 314 and a second waveguide portion 316, which extends substantially vertically through the housing 300 (when the device is oriented for normal use, as illustrated in Figure 9D of the drawings). A second reflective region 317 extends at a return angle of 45 degrees between the end of the second waveguide region 316 and a third waveguide region 318, which extends substantially horizontally through the housing 300 (when the device is oriented for normal use, as illustrated in Figure 9D of the drawings) from the second reflective region 317 to the second, open end 306. Accordingly, the first and second reflective regions 315, 317 are arranged and configured to reflect sound waves entering the channel at the first end 304, first through substantially 90 degrees from the first waveguide region 314 into the second waveguide region 316, and then back through 90 degrees from the second waveguide region 316 into the third waveguide region 318. The external reflector portion 312 ensures that sound waves received at the open first end 304 from the user’s environment are reflected through substantially 90 degrees directly into the first waveguide portion 314.

The distal end of the second waveguide portion 314 and the proximal end of the third waveguide portion 318, both immediately adjacent the second reflecting region 317 (and marked ‘D’ in Figure 9D) effectively form the tuning point and are both of diameter 3.5-3.7mm, as discussed in the other embodiments described above. The ear insert illustrated and described with reference to Figures 9A to 9D is particularly suitable for use at a concert, for example, to significantly improve the user’s experience of the sound.

Referring now to Figures 10A to 10D of the drawings, there is illustrated an ear insert according to another exemplary embodiment of the invention, particularly suited for use under over-ear headphones, to significantly improve the sound therefrom reaching th user’s ears. In this embodiment, most of the features are substantially the same as those described above in relation to the embodiment of Figures 9A to 9D.

Accordingly, an ear insert 400 according to this exemplary embodiment of the invention again comprises a generally tubular housing 402, having a first open end 404 and an open, longitudinally opposing, second end 406. Once again, the second end 406 is shaped and configured to sit, in use, within a user’s ear canal, facing the tympanic membrane. Accordingly, the housing 402 at the second, open end 406 incorporates a first circumferential ridge portion 408 which extends outwardly, at an angle, from the edge of the second, open end 406, along a short portion of the exterior length of the housing 402, and terminates at a first recess 410, over which a resiliently flexible tip (not shown) may be fitted.

The channel extending through the housing 400, between the first and second ends 404, 406, comprises three waveguide portions 414, 416, 418. The first waveguide portion 414 extends from the open first end 404, substantially horizontally through the housing 400 (when the device is oriented for normal use, as illustrated in Figure 10D of the drawings). A first reflective region 415 extends at an angle of 45 degrees extends between the inner end of the first waveguide portion 414 and a second waveguide portion 416, which extends substantially vertically through the housing 400 (when the device is oriented for normal use, as illustrated in Figure 10D of the drawings). A second reflective region 417 extends at a return angle of 45 degrees between the end of the second waveguide region 416 and a third waveguide region 418, which extends substantially horizontally through the housing 400 (when the device is oriented for normal use, as illustrated in Figure 10D of the drawings) from the second reflective region 417 to the second, open end 406. Accordingly, the first and second reflective regions 415, 417 are arranged and configured to reflect sound waves entering the channel at the first end 404, first through substantially 90 degrees from the first waveguide region 414 into the second waveguide region 416, and then back through 90 degrees from the second waveguide region 416 into the third waveguide region 418.

The distal end of the second waveguide portion 316 and the proximal end of the third waveguide portion 318, immediately adjacent the second reflective region 317 (and marked ‘D’ in Figure 10D), effectively form the tuning point and are both of diameter 3.5-3.7mm, as discussed in the other embodiments described above.

Referring to Figure 11 of the drawings, there is illustrated schematically an ear insert according to yet another exemplary embodiment of the invention. In this case, the ear insert 500 comprises a housing 502 having an open first end 504 and a longitudinally opposing second, open end 506. Once again, the second end 506 is shaped and configured to sit, in use, within a user’s ear canal, facing the tympanic membrane. Accordingly, the housing 502 at the second, open end 506 incorporates a first circumferential ridge portion 508 which extends outwardly, at an angle, from the edge of the second, open end 506, along a short portion of the exterior length of the housing 502, and terminates at a first recess 510, over which a resiliently flexible tip (not shown) may be fitted.

The channel 514 extending through the housing 500 between the open first and second ends 504, 506 is a single elongate waveguide portion that extends and tapers from the second open end 506 to a first open end 504, with the narrowest point being adjacent to (and slightly longitudinally offset from) the first open end 504. The narrowest point, marked ‘D’ in Figure 11 , is the tuning point of diameter 3.5-3.7mm, as discussed above in relation to the other embodiments. An elongate tab 514 may extend from an edge of the first, open end 504 to allow the user to insert the ear insert into their ear and remove it again, as required.

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 embodiment without departing from the scope of the invention as defined by the appended claims.

Claims

1 . An ear insert comprising a generally tubular core having an inner wall defining a longitudinal channel for guiding sound waves, in use, from a first end of said channel to a second, open, end thereof, the inner wall defining at least a first waveguide portion extending toward said second, open, end of the channel and defining a tuning point at its narrowest point, the tuning point comprising an opening of diameter 3.5-3.7mm.

2. An ear insert comprising a generally tubular core having an inner wall defining a longitudinal channel for guiding sound waves, in use, from a first end of the channel to a second, open, end thereof, said longitudinal channel having a non- uniform diameter and defining a tuning point at its narrowest point, said tuning point comprising an opening of diameter 3.5-3.7mm.

3. An ear insert according to claim 1 or claim 2, wherein said tuning point comprises an opening of diameter 3.5-3.6mm.

4. An ear insert according to any of claims 1 to 3, further comprising a resi liently deformable tip mounted over the core at the second, open end.

5. An ear insert according to any of claims 1 to 4, wherein said first end of said channel is open and said tuning point is located at or near said second end of the channel.

6. An ear insert according to any of claims 1 to 5, wherein said longitudinal channel comprises a single waveguide portion extending longitudinally between said first end and second ends of said channel, said waveguide portion tapering in diameter from said first end to said second end of said channel, and the tuning point being located adjacent to, and longitudinally offset from, said second end of the channel.

7. An ear insert according to claim 6, further comprising an external tab portion extending from a circumferential edge of said first open end of the channel.

8. An ear insert according to any of claims 1 to 4, wherein said tuning point is located nearer the second end of the channel than the first end of the channel.

9. An ear insert according to any of claims 1 to 5 or claim 8, wherein said channel comprises at least first and second integral waveguide portions.

10. An ear insert according to claim 9, wherein said first and/or second waveguide portion(s) tapers towards said tuning point.

11 . An ear insert according to claim 10, comprising first, second and third integral waveguide portions, with a first acoustic wave reflecting region between said first and second waveguide portions, arranged and configured to reflect sound waves from said first waveguide portion into said second waveguide portion, and onto a second acoustic wave reflecting region between said second and third waveguide portions, arranged and configured to reflect sound waves from said second waveguide portion into said third waveguide portion toward said second, open end of the core.

12. An ear insert according to claim 11 , wherein said first and third waveguide portions are substantially parallel to each other, and said second waveguide portion is substantially orthogonal to said first and second waveguide portions, said first acoustic wave reflecting region Is configured to, in use, reflect sound waves through substantially 90 degrees from said first waveguide portion into said second waveguide portion and onto said second acoustic wave reflecting region, and the second acoustic wave reflecting region is configured to, in use, reflect sound waves back through substantially 90 degrees from said second waveguide portion into said third waveguide portion toward said second open end of the core.

13. An ear insert according to claim 11 or claim 12, wherein said first waveguide portion is configured to guide sound waves from said first end of the core into said channel, wherein said first acoustic wave reflecting region comprises a substantially planar surface that extends from said first sound guiding region generally longitudinally along the inner wall defining said channel at a lateral angle of up to 135° relative to the longitudinal plane defined by said first sound guiding region.

14. An ear insert according to any of claims 9 to 13, wherein said first and second acoustic wave reflecting regions comprise substantially planar respective surfaces.

15. An ear insert according to any of claims 9 to 14, wherein said third waveguide portion is configured to guide sound waves out of said channel through said second open end, wherein said second acoustic wave reflecting region comprises a substantially planar surface that extends generally longitudinally along the inner wall defining said channel, diametrically opposite to, and longitudinally offset from, said first acoustic wave reflecting region, at a lateral angle of up to 45° relative to the longitudinal plane defined by said third waveguide portion.

16. An ear insert according to any of claims 9 to 15, wherein said first and second acoustic wave reflecting regions are substantially parallel to, and at least partially longitudinally offset from, each other along said channel.

17. An ear insert according to any of claims 9 to 16, wherein the ends of the second and third waveguide portions immediately adjacent the second acoustic wave reflecting region are of substantially equal diameter and comprise said tuning point.

18. An ear insert according to any of claims 9 to17, further comprising an external reflecting portion that extends at an angle from an edge of the first end of the core.

19. An ear insert according to claim 18, wherein said external reflecting portion extends at an angle of substantially 45 degrees from an edge of the first end of the core.

20. An ear insert according to claim 9, said longitudinal channel comprising a first tapering waveguide portion that extends from said first end to an opening along the length of said channel, and an integral, longitudinally coaxial second tapering waveguide portion that extends from the second, open end of the core to said opening, wherein said opening comprises said tuning point.

21 .An ear insert according to claim 20, wherein said tuning point is located substantially centrally along the length of said channel.

22. An ear insert according to claim 21 , wherein the taper angles of the waveguide portions are different.

23. An ear insert according to any of the preceding claims, wherein said tuning point is the narrowest part of the channel.

24. An ear insert according to any of the preceding claims, wherein the lateral cross section of the tuning point is substantially circular or oval.

25. An earphone comprising an ear insert according to any of the preceding claims with an external driver unit located at or adjacent said first end of said channel.