Patent Description:
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. The middle ear is a narrow, air-filled cavity known as the ear canal leading from the outer ear to the inner ear, the inner end of the ear canal being closed by a tympanic membrane so as to form a boundary between the middle ear and the inner ear. The outer ear 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 in front and the antitragus behind.

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. The ear canal is essentially a tube that is open at one end (the concha region) and closed at the other end (tympanic membrane). The air inside the ear canal acts as a resonating body. The natural resonant frequency of the ear canal is four times its length (~<NUM> average for an adult) and, therefore, it acts as a quarter-wave resonator and amplifies sound waves. Thus, sound waves enter the ear canal, where they are amplified as they travel through the ear canal until they reach the tympanic membrane and are transmitted to the inner ear. However, the geometry of the outer ear, including the concha, creates an interference in the sound waves as they are 'funnelled' into the ear canal, and this interference, characterized by an incoherent sound wave, is amplified with a gain 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 inner ear.

Furthermore, it has been documented that noise (i.e. intrusive or unwanted sound that disrupts, distracts or detracts from regular functioning) causes stress and can have a negative effect on health and productivity. The vagus nerve, together with the parasympathetic nervous system, is responsible for (amongst other things) triggering the human fight-or-flight stress response. It follows, therefore. That noise can trigger the fight-or-flight response and cause stress. The inventor has discovered that noise distortion created by the geometry of the concha and amplified (especially at frequencies above ~<NUM>) within the ear canal can cause the Vagus nerve to trigger the fight-or-flight stress response. Given that a human being almost constantly receives sound waves from various sources during their day-to-day lives, they are regularly receiving distorted sound amplified at a gain of up to 20dB at the tympanic membrane, and this amplified distorted sound can cause triggering by the Vagus nerve of the fight-or-flight stress response. It follows, therefore, that the average human being may be regularly and persistently in a state of elevated stress, simply due to noise distortion of the type described above.

Clearly, then, there is a desire to reduce the occurrence of noise distortion created and amplified within the human ear canal, without necessarily reducing the quality or volume of the true sound waves reaching the tympanic membrane.

US Patent Application Publication <CIT> describes an earphone including a tubular sidewall having an inner surface defining an air channel extending through the sidewall, that redirects sound at an angle to the speaker axis, and has a smooth contour to maintain sound quality.

European Patent Application <CIT> describes a headphone having a driver unit fixed to a housing and a nozzle inclined by a predetermined angel toward its distal portion. The nozzle section is curved so as to swell inwardly or outwardly.

US Patent Application Publication <CIT> describes a hearing aid having a body and a funneled sound collector.

UK Patent Application <CIT> describes a hearing appliance comprising a hollow permanent magnet attached to a tapered holder.

European Patent Application <CIT> describes an earbud comprising a coupling having a tapered elastomeric sleeve having a rear end that can be expanded to fit around the periphery of the earbud front.

In accordance with a first aspect of the present invention, there is provided an ear insert which has a generally funnel-shaped wall defining a tapering channel extending between first and second open ends, the first open end having a diameter or width greater than that of the second open end, wherein a portion of the funnel-shaped wall immediately adjacent the second open end is configured to enable the ear insert to be located within the opening of a user's ear canal, for use, with the first open end adjacent the user's tragus and the second open end facing the user's tympanic membrane, at least a portion of the tapering channel comprising an acoustic wave reflecting region that extends from a location at or near the first open end toward the second open end at an angle of between <NUM>° and <NUM>° relative to a lateral plane defined by the edge of the funnel-shaped wall at the first open end, characterised in that the acoustic wave reflecting region comprises a substantially planar surface.

In an exemplary embodiment, the acoustic wave reflecting region extends from a location at or near the first open end toward the second open end at an angle of between <NUM>° and <NUM>°, and optionally between <NUM>° and <NUM>°, relative to the lateral plane defined by the edge of the funnel-shaped wall at the first open end.

Beneficially, and in accordance with specific exemplary embodiments, the ear insert may be configured to fit onto or over an ear bud of in-ear headphones. In an exemplary embodiment, the ear insert may be shaped and configured at the second open end to receive and retain a resilient tip.

In one embodiment, the portion of the funnel-shaped wall immediately adjacent the second open end may comprise a generally tubular portion having a longitudinal axis extending at an angle relative to the lateral plane defined by the edge of the funnel-shaped wall at the first open end, the second open end being at the distal end of the tubular portion. Beneficially, the longitudinal axis of the generally tubular portion may extend at an angle of between <NUM>° and <NUM>°, e.g. substantially <NUM>°, relative to the lateral plane defined by the edge of the funnel-shaped wall at the first open end.

Beneficially, the tubular portion may be configured to be inserted into an ear canal, for use, with the second open end facing the user's tympanic membrane and the first open end facing generally rearwardly of the user. Accordingly, the outer diameter of the tubular portion may be between <NUM> and <NUM>, and the diameter of the second open end may be between <NUM> and <NUM>.

In an exemplary embodiment the outer profile of the funnel-shaped wall may comprise a rounded convex region extending from an edge adjacent the first open end to an edge adjacent the second open end, and an opposing concave region at the proximal end of the tubular portion, between the first and second open ends. In this case, the concave region defines a front of the ear insert and the convex surface diametrically opposite defines the rear of the insert, when in use, and the overall length of the funnel-shaped wall may be configured such that, in use, with the tubular portion partly inserted in a user's ear canal, the edge of the first open end at the rear of the ear insert lies adjacent the inner surface of the user's tragus. Beneficially, therefore, the overall length of the funnel-shaped wall may be between <NUM> and <NUM>, and optionally between <NUM> and <NUM> for an average adult.

In a preferred embodiment, a length or the diameter of the first open end may be at least double a length or the diameter of the second open end.

In an exemplary embodiment, the second open end may be generally elliptical. In this case, the length of the first open end may be between <NUM> and <NUM> and the width of the first open end may be between <NUM> and <NUM>.

In a first exemplary embodiment, the ear insert may be integrally moulded of a resiliently deformable material. In a second exemplary embodiment, at least the acoustic wave reflecting region may be formed of a rigid material. For example, the ear insert may comprise an inner member formed of rigid material and defining the tapering channel, and an outer sleeve formed of a rigid or resiliently deformable material. Alternatively, the ear insert may be integrally formed of a rigid material, such as plastic, wood or metal.

In other exemplary embodiments, the tapering channel may communicate, at its narrower end, with a coaxial tube, the inner surfaces of the tapering channel and of the tube being surfaces of revolution about a common longitudinal axis, and the outer surface of the tube defining at least one circumferential ridge or groove, wherein the inner surface of the tube has a diameter of at least <NUM>, the outer surface of the tube has a diameter of no more than <NUM>, and the overall length of the insert is no more than <NUM>.

In this case, the tapering channel may be conical, at least along part of its length, and the angle between the opposed conical surfaces may be between <NUM>° and <NUM>°, and more preferably between <NUM>° and <NUM>°.

The tapering channel may, optionally, have a curved longitudinal shape. For example, the tapering channel may be flared, such that as the diameter decreases, the angle between a tangent to the inner surface and the longitudinal axis also decreases.

In some exemplary embodiments, the narrow end of the tapering channel may have a curved longitudinal shape such that the inner surface of the tube is tangential to the curved longitudinal shape where they meet.

The inner surface of the tube may have a diameter of at least <NUM>, but less than <NUM>, and the outer surface of the tube may have a diameter of no more than <NUM>.

The overall length of the insert may be between <NUM> and <NUM>, and the length of the tube may be between <NUM>% and <NUM>% of the overall length of the insert.

Optionally, at the wider end of the tapering channel, the external diameter may be between <NUM> and <NUM>.

In some preferred embodiments, the dimensions of the ear insert may be such that when the tube, carrying a resilient tip, is inserted into the ear canal, in use, the outer end does not project beyond the tragus.

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

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.

Referring to <FIG> of the drawings, there is illustrated an ear insert <NUM> according to a first exemplary embodiment of the present invention. The ear insert <NUM> comprises a single piece of moulded silicone or other mouldable and resiliently deformable plastics material. The insert comprises a generally rounded outer profile having two integral portions. A first tubular portion <NUM> has a generally oval cross-section and an open first end <NUM>. The outer lateral width OW (<FIG>) of the first tubular portion <NUM> at the open first end <NUM> is in the range <NUM> to <NUM>, for example <NUM> for an average adult, and the outer lateral length OL (<FIG>) is in the range <NUM> to <NUM>, for example, <NUM> for an average adult. The dimensions of the first tubular portion gradually decrease along its length and at the opposing second end <NUM>, the outer diameter OD1 (<FIG>) may be in the range <NUM> to <NUM>, for example, <NUM> for an average adult. An integral second tubular portion <NUM> extends from the second end <NUM> of the first tubular portion <NUM> such that its longitudinal axis is at a <NUM> -<NUM>°, e.g. <NUM>° angle to the longitudinal axis of the first tubular portion <NUM>. The outer profile of the insert is convex and relatively gently rounded on one side (the 'rear') to accommodate the angle between the first and second tubular portions <NUM>, <NUM> and, on the other side (the 'front'), the angle is accommodated by a rounded but relatively sharp concave 'corner' between the first and second tubular portions. The second tubular portion <NUM>, which is open at its distal end <NUM>, is of generally circular cross-section and has an outer diameter OD2 (<FIG>) in the range <NUM> to <NUM>, for example, <NUM> for an average adult and length L1 (<FIG>) in the range <NUM> to <NUM>, for example, <NUM> for an average adult. It will be appreciated that the various dimensions can be altered within the ranges given to suit smaller or larger ears, and even child's sizes, as required.

Referring additionally to <FIG> of the drawings, the first and second integral portions <NUM>, <NUM>, together, define a continuous channel <NUM> therethrough which, itself, is comprised of two portions: the first channel portion <NUM> being defined through the first tubular portion <NUM> and the second channel portion <NUM> being defined through the second tubular portion <NUM>. The first channel portion is defined, along the 'front' and 'sides' by the oval-shaped rounded profile of the first tubular portion <NUM>. However, the 'rear' wall of the first tubular portion <NUM> is thicker than the remaining walls so as to provide a 'rear' channel portion <NUM> that is substantially flat so as to provide a planar surface <NUM>. As shown in <FIG> of the drawings, when the insert <NUM> is in an 'upright' position, with the lateral plane of the first open end <NUM> being horizontal, the planar surface <NUM> of the first channel portion <NUM> extends at an acute angle, greater than <NUM>°, toward the second channel portion <NUM>, and the diameter or width of the first channel portion <NUM> reduces from the open end <NUM> to the junction with the second channel portion <NUM> defined by the second tubular portion <NUM>. The angle of the planar surface <NUM>, relative to horizontal defined by the lateral plane of the first open end <NUM> may be in the range <NUM> to <NUM>°, for example, <NUM>° for an average adult.

As described above, and best illustrated by <FIG>, the angled configuration of the second tubular portion <NUM> relative to the first tubular portion <NUM> is accommodated at the 'rear' and 'sides' of the insert by a gently rounded outer wall that curves from the first open end <NUM> to the distal second open end <NUM> defined by the second tubular portion <NUM>. As stated above, the length L1 (<FIG>) of the second tubular portion <NUM> is in the range <NUM> to <NUM>, for example, <NUM> for an average adult. The diameter ID (<FIG>) of the distal open end <NUM> may be in the range <NUM> to <NUM>, for example, <NUM> for an average adult. It will be appreciated that, whilst the open end <NUM> of the second tubular portion <NUM> is illustrated as being generally circular in this exemplary embodiment, it may have an alternative shape and configuration. For example, it may be generally oval or 'slit-like' in other exemplary embodiments and the present invention is not necessarily intended to be limited in this regard. The thickness of the 'front' and 'side' walls of the second tubular portion <NUM> are substantially constant along the length to the junction between the first and second tubular portions <NUM>, <NUM>, defined by the concave rounded 'corner' <NUM>. However, whilst the diameter of the second channel portion <NUM> is substantially constant from the distal open end <NUM> along a portion of the length of the second tubular portion <NUM>, it tapers inwardly (by means of a thickening of the rear wall of the second tubular portion <NUM>) along a short portion toward the junction between the first and second tubular portions <NUM>, <NUM>, such that that short portion of the inner rear wall of the second channel portion <NUM> forms an extension of the planar surface <NUM> defining the 'rear' wall of the first channel portion <NUM>.

An elongate tab <NUM> may be provided, extending from the rim of the first tubular portion <NUM>, at its open end <NUM>, to facilitate insertion of the device into, and removal of the device from, a user's ear.

In the exemplary embodiment described above, the ear insert <NUM> is integrally moulded from a resiliently flexible material such as silicone. However, in an alternative exemplary embodiment, the insert <NUM> may have a two-part configuration. In this case, the device may comprise a metal (e.g. stainless steel or titanium) insert providing defining the first and second channel portions <NUM>, <NUM> (i.e. the channel including the planar surface <NUM>) and an outer sleeve, formed of a resiliently flexible material such as foam or silicone, defining the curved outer profile to enable the device to be comfortably fitted within a user's ear. The reduction in noise distortion when the planar (reflecting) surface <NUM> is formed of a rigid material can thus be further increased.

In use, the ear insert <NUM> is inserted into a user's ear at the open end of the ear canal (adjacent the concha region) such that the second tubular portion extends into the ear canal (with the distal open end <NUM> facing the tympanic membrane at the other end of the ear canal), and the rounded 'rear' surface of the first tubular portion <NUM> resting at or just behind the tragus, with the first open end <NUM> facing backward. It will be appreciated that the outer diameter (OD2) of the second tubular portion <NUM> is designed, in this example, to be around the same as that of the entrance of the ear canal (external auditory canal) of an average adult. The overall length of the insert <NUM> (excluding the tab <NUM>) is approximately equal to the average length of the external auditory canal of an average adult, wherein the external auditory canal comprises the ear canal extending from the tragus to the middle ear. As a result, the insert <NUM> can be fully inserted into the external auditory canal, with the outer edge of the first tubular portion <NUM> resting against the rear (inner) surface of the tragus and the second tubular portion <NUM> extending a short way into the ear canal, with the distal open end <NUM> facing the tympanic membrane.

As described above, at least the outer wall of the insert <NUM> is beneficially formed of a soft, resiliently deformable material, such as silicone, so that it can be compressed sufficiently to be inserted into the ear and then released back to its original form, once inserted, to fit snugly within the ear. In the example illustrated in <FIG> and <FIG>, the insert (including the profiled inner channel) is integrally formed of a mouldable material such as silicone. However, and as stated above, in alternative embodiments, the device may comprise an inner member defining the profiled inner channel including the planar surface <NUM>, and an outer sleeve member around the inner member. In this case, the inner member may be formed of a rigid material such as plastic or metal (e.g. stainless steel or titanium), and the sleeve member could be formed of a resiliently deformable material such as silicone, to provide a comfortable snug fit, in use.

The angle defined by the longitudinal axis of the second tubular portion <NUM> is at substantially <NUM>° to the diametric plane defined between the rim around the first open end <NUM>, and the angle of the planar surface <NUM> provided at the 'rear' inner surface of the first channel portion <NUM> (and a small portion of the second channel portion <NUM>) is at substantially <NUM>° relative to the longitudinal axis of the second tubular portion <NUM>. The inventor has discovered that these relative angles, and especially the angle of the planar reflecting surface <NUM> relative to the first and second open ends <NUM>, <NUM> of the insert, can provide optimum results in adults with average ear dimensions. Furthermore, and as stated previously, all dimensions, especially the outer dimensions of the tubular portions <NUM>, <NUM>, can be adjusted (particularly within the tolerances provided) to accommodate, for example, children's' ear dimensions, or adults having larger or smaller external auditory canals.

Once the device is in situ, with the distal open end <NUM> of the second tubular portion <NUM> located in the ear canal facing the tympanic membrane, and the 'upper' edge of the first tubular portion <NUM> resting against the rear (inner) surface of the tragus, with the first open end <NUM> facing backward, it effectively acts to minimise or even eliminate the effect of the concha on sound waves entering the ear. The device still 'funnels' sound waves into the ear canal, due to its tubular shape and configuration, having a first open end <NUM> of width over double the diameter of the second, distal end <NUM>. The angled planar surface <NUM> acts to minimise the number of times sound waves reaching the external auditory canal are reflected before they reach the tympanic membrane. Given that it is these reflections that create incoherence in the sound waves, and it is this incoherence that represents distortion or 'noise' that is then amplified within the ear canal, it will be clear that the device, in use, acts to reduce distortion in sound waves reaching the tympanic membrane. Without the device, sound waves from a listener's vicinity reach the external auditory canal in the concha region which defines surfaces that can be at up to <NUM>° relative to the longitudinal axis of the ear canal (leading to the tympanic membrane). Thus, sound waves reaching the external auditory canal must change direction by up to <NUM>° to reach the tympanic membrane. However, sound waves, especially those over around <NUM> which are not highly diffracted, can only 'change direction' in this manner by repeated reflection within the concha region, until they are oriented to enter the ear canal. The configuration of the external auditory canal, with its grooves and ridges, is such that these sound waves can be reflected many times before entering the ear canal. These reflections result in primarily incoherent sound waves entering the ear canal and such incoherent sound waves (representing significant distortion or 'noise') are amplified within the ear canal before they reach the tympanic membrane. In contrast, the ear insert of the present invention acts to 'funnel' more coherent sound waves into the ear canal, with significantly less reflections, thereby reducing distortion (or 'noise') by up to <NUM>% or more. If the user is wearing the insert whilst listening to music, for example through headphones as described above, the quality and clarity of the music heard by the listener is notably improved. Furthermore, and most surprisingly, if a user is wearing the insert(s) whilst conducting their normal day to day lives, the significant reduction in noise distortion provided by the insert(s) acts to reduce instances of triggering, by the Vagus nerve, of the fight-or-flight stress response. Thus, by wearing the insert of the present invention (preferably one in each ear), the user experiences a calming effect, in that stress is reduced during their normal day-to-day lives.

Referring to <FIG> of the drawings, the effect of the planar (reflecting) surface <NUM> within the channel is illustrated schematically. In <FIG>, the incoming sound wave <NUM> enters the first channel portion <NUM> at an angle of <NUM>° relative to the 'horizontal' defined by the plane of the first open end <NUM> of the insert <NUM>. Is illustrated, the incident sound wave <NUM> hits the reflecting surface <NUM> within the first tubular portion <NUM> of the device <NUM> and the resultant reflected sound wave <NUM> is directed straight through the second opening <NUM> toward the tympanic membrane. Thus, only a single coherent sound wave enters the ear canal. Similarly, and as shown in <FIG>, incident sound waves <NUM> at an angle of <NUM>°, <NUM>°, <NUM>°, and <NUM>° respectively, are reflected by the reflecting surface <NUM> straight through the second opening <NUM> in the insert <NUM> toward the tympanic membrane.

In the embodiment described above, the ear insert is a stand-alone device for use in improving the quality and clarity of sound heard by a user, who may or may not be wearing headphones. In alternative embodiments, an insert of the present invention may be configured to be fitted over each of the integral ear buds of a set of wireless headphones, or as a tip for any existing ear phones with tube output. In yet another exemplary embodiment, an insert according to the invention may be configured to be fitted with resiliency deformable tip, such as that used in conventional earplugs and in-ear headphones.

Claim 1:
An ear insert (<NUM>) which has a generally funnel-shaped wall defining a tapering channel extending between first and second open ends (<NUM>, <NUM>), the first open end (<NUM>) having a diameter or width greater than that of the second open end, wherein a portion of the funnel-shaped wall immediately adjacent the second open end (<NUM>) is configured to enable the ear insert to be located within the opening of a user's ear canal, for use, with the first open end (<NUM>) adjacent the user's tragus and the second open end (<NUM>) facing the user's tympanic membrane, at least a portion of the tapering channel comprising an acoustic wave reflecting region (<NUM>) that extends from a location at or near the first open end (<NUM>) toward the second open end (<NUM>) at an angle of between <NUM>° and <NUM>° relative to a lateral plane defined by the edge of the funnel-shaped wall at the first open end; characterised in that the acoustic wave reflecting region (<NUM>) comprises a substantially planar surface.