EP3490268B1

EP3490268B1 - Earphone

Info

Publication number: EP3490268B1
Application number: EP19151523.8A
Authority: EP
Inventors: Jesper Brehmer; Marcus Hoggarth
Original assignee: B&W Group Ltd
Current assignee: Bowers and Wilkins Group Ltd
Priority date: 2009-12-23
Filing date: 2010-12-22
Publication date: 2022-05-04
Anticipated expiration: 2030-12-22
Also published as: EP3490268A1; EP2517475A1; DE202010018637U1; WO2011077160A1; GB0922610D0

Description

The present invention relates to an earphone, which typically (but not exclusively) is adapted for connection to an electronic device with an electronic sound output adapted for that purpose (such as an MP3 player, radio, digital versatile disk player or a compact disk player), particularly an electronic device carried on the person.
The transmission of electrical impulses to a sound-generating earphone body which is located near to or in the external auditory meatus (otherwise known as the ear canal) is well-known. For many years, headphones have been used, the headphones typically comprising a band connecting two earpieces, the earpieces typically being placed against, or slightly spaced from, the pinna (the outer part of the ear) of the ear. The band is typically resiliently deformable so that the earpieces are engaged against the head or ears of the wearer so as to ensure satisfactory transmission of sound to the user and to inhibit inadvertent, unwanted removal of the earphone. Such headphones are typically large, not discreet and may be heavy. Furthermore, the earpieces themselves typically rest against (or are slightly spaced from) the pinna and are therefore relatively distant from the eardrum, therefore meaning that more electrical power is required to achieve a certain perceived volume of sound.
Earphones are known which have an earphone body which, in use, is at least partially located within the ear, for example, either in the external auditory meatus or behind the tragus, but not in the external auditory meatus. The tragus is the small pointed eminence extending rearwardly, partially over the external auditory meatus, from the front part of the pinna immediately above the ear lobe.). Such earphones generally require less power to achieve a certain user-perceived volume than headphones because the sound-generating part (the earphone body) is located closer to the ear drum. Such earphone bodies are typically held in place by an interference fit between the earphone body and the ear. There are problems with such earphones, however. The earphone bodies may not be suited to the ear anatomy of a wide spectrum of users. For example, small ears (such as those of children) may not be able to accommodate such earphones. Furthermore, such earphone bodies are prone to unwanted removal from the ear, should the interface between the ear and the earphone body become wet, for example, during exercise or during wet weather.
One way of overcoming the problem of unwanted removal of the earphone body is to provide the earphone with a retaining clip which, in use, is located around the external perimeter of the pinna between the pinna and the head of the wearer. Such earphones may be considered to be unsightly. Furthermore, whilst some such earphones are provided with one or more forms of adjustment (such as the retaining clip being pivotally mounted to allow it to be clamped around the back of the pinna) the earphone cannot be readily adjusted to individual ear anatomies.
Document US 2003/174853 discloses an earphone comprising a loop of variable length and geometry.
Document US 2009/180653 discloses a behind the ear hearing device having an earphone connected to the body of the hearing device by a cable of variable length which forms a loop of a variable size depending on retraction length of the cable. The loop formed by the cable at the body of the hearing device is not engaged in holding the hearing aid in an ear of a wearer.
The present invention seeks to mitigate one or more of the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved earphone.
In accordance with the present invention, there is provided an earphone as set forth in claim 1. The earphone comprises a loop of variable geometry formed at least in part by a part of the transmission cable, which, when the earphone body is in place, is adapted to be located at least partly in the concha of the wearer and to engage the surface of the ear. It has been found that such a loop advantageously assists retention of the earphone body in the ear of the wearer. The surface of the ear typically engaged by the loop may include a surface of the ear which forms the concha. The surface of the ear typically engaged by the loop may include an inner portion of the surface of the ear which forms the antihelix.
The loop of variable geometry enables the earphone to be used by people having very different ear sizes and shapes. The loop has a variable length. The geometry and/or length of the loop may be adjusted so that the loop engages the surface of the ear in the concha. The earphone of the present invention advantageously improves resistance to unwanted removal from the ear of the wearer.
The earphone body may be of the in-ear type, which is adapted to be at least partly located in the external auditory meatus of a wearer. The earphone may be provided with a cushion which is typically mounted on the earphone body and is, in use, inserted into the external auditory meatus.
Alternatively, the earphone body may be adapted to be located adjacent to the external auditory meatus (as opposed to any part of the earphone being located in the external auditory meatus), the earphone body being adapted to be at least partly located immediately to the rear of the tragus.
Additionally or alternatively, the earphone may be considered as being an "intra-aural" earphone in which at least a part of the earphone either extends into the ear canal or extends directly over the entrance to the ear canal.
The earphone comprises a transmission cable for the transmission of electrical signals to the speaker. The transmission cable is typically connected at one end to the speaker of the earphone and is typically adapted at the opposite end for connection to an electronic sound output of an electronic device, such as an MP3 player. The opposite end of the transmission cable may for example terminate with a connector, for example an audio jack or plug, for insertion into the output audio socket of an electronic audio device. The earphone is typically a passive audio device. For example the earphone may be arranged such that it does not need its own independent power supply and/or electrical signal amplifier. Whilst the present invention could have application in relation to hearing aids, it is preferred that the earphone be configured for use with personal audio equipment without any need for microphone means in or near the ear of the user.
The loop may be formed by a cord. The cord may be configured so that in use it engages the surface of the ear, thereby restricting removal of the earphone body. The cord forming the loop may be thicker (i.e. having a greater external diameter) than at least part of the transmission cable not forming the loop. For example, a portion of the transmission cable remote from the loop (for example, nearer to a jack plug to be inserted into a device such as an MP3 player) may be thinner than the cord forming the loop. The material, for example the cord mentioned above, forming the loop may have a thickness greater than the median thickness of the transmission cable. The cord may be formed by means of a sheath formed around the transmission cable. The cord may simply be formed of a single type of material, and may for example be defined by a length of plastics material. The cord preferably has a diameter of less than 5mm.
The loop is formed at least in part by the transmission cable. The use of the transmission cable to form the loop simplifies the device and does away with the need for a further loop-forming feature. The loop may be formed substantially entirely by a portion of the transmission cable (i.e. without any extra sheath around the cable).
The loop is preferably made from flexible material. The loop preferably has a resiliency. The resilient (springiness) nature of the loop may conveniently result from the material of the transmission cable.
The earphone body may be provided with one or more loop guides for assisting in forming the loop. The loop guide may be in the form of a passage that extends either partly into or completely through the earphone body. The loop guide may be in the form of a recess in the earphone body. The recess in the earphone body may be in the form of an aperture. The recess in the earphone body may be in the form of a groove. The axis of the passage or recess may not be parallel to the axis of the earphone body. The axis of the passage or recess is preferably transverse to the axis of the earphone body. The angle between the axis of the passage or recess and the axis of the earphone body (or a line parallel to the axis of the earphone body which intersects the axis of the passage or recess) may be from 50° to 90°.
The earphone may be provided with a means for fixing the length or shape of the loop. The means for fixing the length or shape of the loop may also act as a loop guide for assisting in forming the loop. The means for fixing the length or shape of the loop may be in the form of a recess. For example, if the loop is formed by a cord, the cord forming the loop may form an interference fit with the recess. The recess may be formed in the perimeter of the earphone body. The means for fixing the length or shape of the loop may be arranged to releasably fix the length or shape of the loop. For example, if the means for fixing the length or shape of the loop is in the form of a recess and the cord forms an interference fit with the recess, then the cord and recess may be adapted so that the cord is releasable from the recess by use of an appropriate amount of force. The appropriate force would inhibit unwanted, accidental removal of the cord from the recess, but would not be so large that removal of the cord from the recess could damage the earphone.
The loop may define a closed loop. In this case, the loop may typically be formed by a cord, one end of the cord being attached to the earphone body and another part of the cord separated from said end, said other part being connectable to the earphone body. It will be appreciated that the loop may therefore form a closed loop by means of a part of the cord and a part of the earphone body. The attachment of the transmission cable to the earphone body forming the electrical connection to transmit signals to the speaker may define said "one end of the cord" attached to the earphone body.
The loop may be an open loop. The degree to which the loop may be open depends, inter alia, on the material from which the loop is made, but the loop should help inhibit unwanted removal of the earphone body from the ear of the wearer.
The loop is preferably not circular. Preferably, the loop, when the earphone is being worn, adopts a shape that matches the contours of the ear which define the concha sufficiently closely that the loop assists retention of the earphone in the ear. The loop, when worn, may have a shape in the general form of a teardrop.
The loop may be formed such that it engages the earphone body at two discrete positions that are located at different axial positions along the length of the earphone body. The loop may therefore be positioned on a plane that has a normal axis that is not parallel with the axis of the earphone (the axis along the length of the earphone). The loop may therefore (if not in the ear) tilt away from the perpendicular to the earphone axis. The tilt of the loop, if present, may assist in retaining the earphone in the ear. The tilt of the loop, if present, may assist in the correct positioning of the earphone in the ear.
The earphone body may typically comprise a housing which houses the speaker. The recess or passage for guiding the loop and/or for fixing the length or shape of the loop may be formed in the housing. The recess (be it formed in the housing or elsewhere) may be elongate and may be straight or curved. The recess may be a spiral, for example, forming a spiral groove in the periphery of the housing.
The earphone may comprise a cushion, said cushion being mounted on the earphone body and optionally being adapted for insertion into the external auditory meatus of a wearer.
Without wishing to be limited by theory, the applicant believes that the loop used in the earphone of the present invention may help inhibit unwanted removal of the device in one or more of the following ways. When the earphone body is of the in-ear type, the loop may assist is urging the earphone body into the ear canal. The contact force between the loop and the ear may resist removal of the earphone. The loop may generate an upwards force on the earphone body which resists the natural tendency of the earphone body to fall downwards and out of the ear. At least part of the loop may be located behind the antihelix of the ear, a ridge-like structure, thereby inhibiting unwanted removal of the earphone body.
The earphone body may extend rearwardly from a front portion adapted to be inserted into the ear of a wearer, the earphone body comprising a first portion provided by a first material and a second portion provided by a second material different from the first material, the second portion being located forward of the first portion.
The centre of gravity of the earphone body may be located forward of the first portion of the earphone body. This provides a well-balanced earphone body which resists accidental removal from the ear of the wearer. Preferably, the centre of gravity of the ear phone body is located such that in use it is positioned inwardly of the intertragic notch of the ear of the user. This may provide further assistance with the retention of the earphone body within the ear.
The density of the second material may be at least 7gcm^-3. Such a weighted earphone resists accidental removal from the ear of the wearer.
The first portion may be provided by a housing. The first portion may comprise a plastics material or aluminium. The first portion may be provided by a material having a density of less than 3gcm^-3.
The second portion typically comprises a skirt which abuts with the first portion of the earphone body and a forwardly-extending tubular portion. Such a second portion typically comprises a sound tube for transmitting sound to the ear of the wearer.
The mass of the second portion is typically at least 5g, preferably at least 8g and more preferably at least 10g. Having a massive second portion may assist in making the earphone more massive, which in turn may act to damp any accidental cable tugging of the earphone, for example via the earphone signal transmission cable.
The mass of the first portion (especially if the first portion is provided by a housing) may typically be less than 3g and preferably less than 2g.
The ratio of the mass of the second portion to the first portion may be at least 3:1, preferably at least 5:1 and more preferably at least 8:1 and further more preferably at least 15:1.
It is preferred that the second portion has a density of at least 7gcm^-3, preferably at least 12 gcm^-3 and further more preferably at least 15 gcm^-3.
It is preferred if the second portion comprises (and further preferred that the second portion is formed from) one or more of steel, tungsten and a tungsten alloy, such as a tungsten:copper alloy. The provision of such massive, dense and/or stiff material may reduce undesirable vibration in the earphone during use.
The earphone body may have a length as measured from the front to the rear of the earphone body. The length of the earphone body does not take into account the presence of a cushion which may be mounted onto the earphone body for comfort and to achieve a seal with the surfaces of the ear. The centre of gravity of the earphone body may be closer to the front of the earphone body than the rear of the earphone body. The distance between the front of the earphone body and the centre of gravity as measured along the length of the earphone body may be less than 40% of the length of the earphone body, preferably less than 30% of the length of the earphone body and more preferably about 25% of the length of the earphone body.
The earphone body may have a mass of at least 10g.
The earphone may be provided with a further earphone retaining means. For example, the further earphone retaining means may comprise a second loop, the second loop being arranged, in use, to be located externally of the pinna, between the pinna and the head of the wearer. Such an arrangement would provide further resistance against unwanted removal of the earphone from the ear of the wearer.
It may be that the earphone body extends rearwardly from a front portion adapted to be inserted into the ear of a wearer, and comprises a first portion provided by a first material and a second portion provided by a second material different from the first material, the second portion being located forward of the first portion, wherein the centre of gravity of the earphone body is located forward of the first portion of the earphone body and/or the density of the second material is at least 7gcm^-3. Such an earphone may be more resistant to unwanted movement caused by the weight of any transmission cable. Furthermore, location of the centre of gravity forward of the first portion may provide an earphone which forms a better seal with the ear, thereby improving the listening experience of the wearer.
The first portion may be provided by a housing. The first portion may comprise a lightweight metal alloy, such as an aluminium alloy. The first portion may be provided by a material having a density of less than 3gcm^-3.
The second portion typically comprises a skirt which abuts with the first portion of the earphone body and a tubular portion extending forward from the skirt. Such a second portion typically comprises a sound tube for transmitting sound to the ear of the wearer.
The mass of the second portion is typically at least 5g, preferably at least 8g and more preferably at least 10g.
The mass of the first portion (especially if the first portion is provided by a housing) may typically be less than 3g and preferably less than 2g.
The ratio of the mass of the second portion to the first portion may be at least 3:1, preferably at least 5:1 and more preferably at least 8:1 and further more preferably at least 15:1.
It is preferred that the second portion has a density of at least 7gcm^-3, more preferably at least 12 gcm^-3 and further more preferably at least 15 gcm^-3.
It is preferred if the second portion comprises (and further preferred that the second portion is formed from) one or more of steel, tungsten and a tungsten alloy, such as a tungsten:copper alloy.
The earphone body may have a length as measured from the front to the rear of the earphone body. The length of the earphone body does not take into account the presence of a cushion which may be mounted onto the earphone body for comfort and to achieve a seal with the surfaces of the ear. The centre of gravity of the earphone body may be closer to the front of the earphone body than the rear of the earphone body. The distance between the front of the earphone body and the centre of gravity as measured along the length of the earphone body may be less than 40% of the length of the earphone body, preferably less than 30% of the length of the earphone body and more preferably about 25 % of the length of the earphone body.
In accordance with a further aspect there is provided an earphone set, the earphone set comprising an earphone in accordance with the present invention as described or claimed herein. The earphone set may include a connector arranged for the transmission of electrical signals to the speaker of the earphone of the present invention and arranged for connection to a corresponding connector. The connector of the earphone set may for example facilitate connection to an electrical sound output of an electronic device, for example an MP3 player. The earphone set typically comprises a transmission cable for the transmission of electrical signals from the connector to the speaker. The transmission cable is conveniently connected at one end to the speaker and at the opposite end to the connector.
The earphone set preferably comprises a further earphone, such that for example the earphone set comprises a pair of earphones. The further earphone typically comprises a speaker. The connector is preferably arranged for the transmission of electrical signals to the speaker of the further earphone (i.e. so that the connector is connected to both earphones of the earphone set). It is preferred that the further earphone comprises an earphone in accordance with the present invention as described or claimed herein. The earphone set may comprise a stereo connector adapted for connection to an electrical stereo sound output of an electronic device. In such a case, the transmission cables of each earphone may each be connected at one end to the speaker of the respective earphone and connected at the opposite end to the stereo connector.
The connector typically comprises a male plug, such as a 3mm jack plug. The corresponding connector may comprise a female connector to receive a male connector.
Embodiments of the present invention will now be described by way of example only with reference to the following figures of which:

Figure 1 shows an earphone according to a first embodiment of the present invention located in the ear of a wearer;
Figure 2 is a stylised cut-away image of the ear showing the earphone of Figure 1 located in the ear of a wearer;
Figure 3a is perspective image of an earphone according to a second embodiment of the present invention, the transmission cable of the earphone being formed into a loop;
Figure 3b is a perspective image of the earphone of Figure 3a, the transmission cable not being formed into a loop;
Figure 3c is perspective see-through image of a variation of the earphone of Figure 3a;
Figure 4 is an image showing the earphone of Figure 3a and 3b in the ear of a wearer;
Figure 5 is an image showing the earphone of Figure 3a and 3b in the ear of a different wearer from that shown in Figure 4;
Figure 6 is a perspective image showing an earphone according to a third embodiment of the present invention;
Figure 7a is a schematic sectional view of an earphone according to a fourth embodiment of the present invention;
Figure 7b is a schematic exploded view of an earphone very similar to that shown in Figure 7a;
Figures 8a and 8b are exploded perspective views of an earphone according to a fifth embodiment of the present invention, but not showing the speaker; and
Figure 8c is an exploded side view of an earphone very similar to that shown in Figures 8a and 8b, but also including a speaker.

Figure 1 is a perspective view of an earphone according to a first embodiment of the present invention, the earphone being worn. The earphone, denoted generally by reference numeral 1, comprises an earphone body 2 connected to a transmission cable 3 at point 6. The transmission cable 3 carries signals to a speaker (not shown) housed in the earphone body 2 from a signal-generating device (not shown) such as an MP3 or MP4 player, a mobile phone, a computer, a radio or compact disk player. The transmission cable 3 passes through a passage (visible as feature 7 in Figure 2) in the housing 5 of the earphone body 2. The connection of the cable 3 to the earphone body 2 at point 6, coupled with the cable passing through passage 7 in housing 5, facilitates the formation of a loop 4. The size of the loop 4 may be altered simply by the user by playing more cable into the loop or by pulling the cable so as to decrease the size of the loop.
Referring to Figures 1 and 2, in order to fit the earphone 1, the sound tube 8 (bearing cushion 9) is inserted into the external auditory meatus M of the wearer, with the loop 4 being of sufficiently small size so that it does not hinder placement of the earphone body 2. Once the earphone body 2 is in place, the user may then increase the size of the loop 4 by playing-out more transmission cable 3 into the loop 4. Alternatively, the size of the loop 4 can be pre-set, for example from a previous fitting, and then simply inserted and used on successive occasions without adjustment. The loop is sufficiently flexible that it may be manoeuvred around the features of the ear. The portion of the cable within the passageway 7 is held in position by means of friction.
As can be seen from Figure 1, a significant portion (if not all) of the loop 4 is located within the concha C of the wearer. A portion of the loop is located behind the antihelix A, thereby resisting unwanted withdrawal of the earphone body. Furthermore, as the lower portion of the loop 4 is urged into contact with the lower portion of the ear, an upwards force is generated at the connection point 6 on the earphone body 2. This provides a supporting force which resists the natural tendency of the earphone body 2 to fall from the ear under the influence of gravity. The loop 4 also acts to resist movement of the earphone body 2 out from the ear (in the direction from left to right in Figure 2) by means of the stiffness of the loop and the engagement of the loop 4 on the antihelix A of the ear. Figure 2 shows the approximate position of the intertragic notch N of the ear, referred to later in connection with a different embodiment. As mentioned in the text in Figure 1, it will also be seen that the cable follows, in part at least, the lower ear pocket thus assisting further in the correct positioning of the earphone body in the ear canal.
Figures 3a and 3b show an earphone 101 according to a second embodiment of the present invention, and Figure 3c shows an earphone 101 that is a variation on the second embodiment. Whilst the earphone of Figure 1 was provided with a passage through the earphone body to guide the transmission cable, the earphone of Figures 3a to 3c is provided with a recess 107 to guide the transmission cable. The earphone, denoted generally by reference numeral 101, comprises an earphone body 102 comprising a housing 105 (which houses a speaker (not shown)) and a cushion 109. As with the earphone of Figure 1, the cushion 109 of earphone 101 is inserted into the external auditory meatus of the wearer, typically with a very small loop 104 or with the loop not formed. The loop 104 is formed by passing the transmission cable 103 into recess 107 which is shaped so that the cable press-fits into the recess, but once in the recess, the cable may be moved along the recess by means of the user overcoming the friction between the cable and the recess, thereby permitting the length of the loop to be changed. The opening of the recess 107 through which the cable is introduced and removed is sized so that the deformation of the cable sheathing is required on the introduction or removal of the cable. This results in resistance to unwanted removal of the cable 103 from the recess 107. Once the earphone body is in place in the ear, the wearer may adjust the size of the loop in a manner analogous to that described above in relation to Figures 1 and 2. Adjustment of the loop once initially fitted may not be required from one use to the next. The earphone of Figure 3c is substantially the same as that of Figures 3a and 3b, the principal difference being the shape of the cushion 109.
Figures 4 and 5 show the earphone of Figures 3a and 3b in use in the ears of two different wearers. As can be seen from Figures 4 and 5, at least a portion of the loop 104 is located in the concha of each of the wearers. As in Figure 1, the loop 104 acts on the features of the ear to resist both (a) downward movement of the earphone body 102 that might result from the force resulting from gravity and (b) movement of the earphone body 102 parallel to the earphone axis and out of the ear. The loop thus aids secure retention of the earphone body within the ear.
Figure 6 shows an example of an earphone in accordance with a third embodiment of the present invention. The earphone is denoted generally by reference numeral 201 and comprises an earphone body 202 connected to a transmission cable 203. The earphone body 202 is provided with a spiral-shaped recess 207 into which the transmission cable 203 may be inserted so as to form a loop. The cable 203 and recess 207 are adapted so that the cable forms an interference fit with the recess 207, therefore when the cable is pressed into the recess, the length of the loop is effectively fixed. The cable 203 may, of course, be removed from the recess 207 and the cable replaced in the recess so as to form a loop of different length.
Figure 7a shows a schematic section of an earphone in accordance with a fourth embodiment of the present invention. An exploded view of a variant on Figure 7a, with some minor geometrical differences, is shown in Figure 7b. The earphone, denoted generally by reference numeral 601, comprises a rear portion 602 in the form of a plastics housing in which is located a speaker 610. The earphone also includes a cushion 609 for insertion into or arrangement against the ear canal. The earphone 601 further comprises a sound tube 608 located forward of the rear portion 602. A transmission cable 603 extends through an aperture (not shown) provided in the housing 602 to the speaker 610 (only shown in Figure 7b). A knot 611 formed in the transmission cable 603 provides strain relief for the speaker 610. The sound tube 608 is made from a tungsten-copper alloy (about 75% tungsten to 25% copper, by weight, thereby having a density of about 14.6gcm^-3), ensuring that the centre of gravity of the earphone body is located forward of the rear portion 602. The plastic rear portion 602 has a mass of about 1g, whereas the front portion (sound tube) 608 has a mass of the order of 10g. The comparatively large weight at the front of the earphone provided by the tungsten sound tube 608 reduces the tendency of the earphone body to be removed from the ear or to be displaced from a position which provides good transmission of sound. This is achieved because the weight W of the ear phone (except the cable 603) effectively acts downwards onto a part of the ear inside from the intertragic notch N from the centre of gravity. The earphone is thus securely seated and positioned in the ear. The approximate position of the intertragic notch is shown in Figure 2. Any downward force caused by the cable 603 may thus be balanced by the weight W of the earphone body.
It is also expected that the centre of gravity being located towards the front of the earphone body provides a good seal between the external auditory meatus and the earphone 601, therefore providing good transmission of sound to the ear of the wearer, with minimal interference from other sound sources. The distance from the front of the earphone body (the end of sound tube 608) to the centre of gravity of the earphone body is approximately 30% of the length of the earphone body (as measured in the direction shown by the double headed arrow in Figure 7b) and is located within the envelope of the sound tube.
A further advantage that may result when providing a tungsten sound tube is that the earphone may suffer from fewer unwanted vibrations than earphones having sound tubes made from different, less dense, less massive, and/or less stiff material. Also the extra mass reduces the chance of the earphone being accidentally tugged as a result of the extra inertia to movement that may be provided.
Figures 8a and 8b show a schematic section of an earphone in accordance with a fifth embodiment of the present invention. An exploded view of a variant on Figures 8a and 8b, with some minor geometrical differences, is shown in Figure 8c.
The earphone, denoted generally by reference numeral 801, comprises a cushion 809 and a rear portion 802 in the form of a plastics housing in which is located a speaker 810. The earphone 801 further comprises a sound tube 808 located forward of the rear portion 802. A transmission cable 803 extends through an aperture (not shown) provided in the housing 802 to the speaker 810. A knot 811 formed in the transmission cable 803 provides strain relief for the speaker 810. The sound tube 808 is made from tungsten (having a density of about 19gcm^-3), ensuring that the centre of gravity of the earphone body is located forward of the rear portion 802. The comparatively large weight at the front of the earphone body provided by the tungsten sound tube 808 reduces the tendency of the earphone body to be removed from the ear or to be displaced from a position which provides good transmission of sound. Furthermore, transmission cable 803 extends through a passage 807 (not shown in Figure 8c) so as to form a loop 804 of transmission cable 803 substantially as described above in relation to the earphone of Figures 1 and 2. At least part of the loop 804 may, in use, be located in the concha of a wearer, and the size of the loop may be varied substantially as described above in relation to the earphone of Figure 1 and 2 and may engage with the ear to inhibit unwanted removal of the earphone body from the ear. The distance from the front of the earphone body (the end of sound tube 808) to the centre of gravity of the earphone body is approximately 30% of the length of the earphone body (as measured in the direction shown by the double headed arrow in Figure 8c). The use of a loop and a shift in the centre of gravity is thought to be a particularly effective combination of features which allows reliable positioning and secure retention of the earphone during use.
Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.
The embodiments above all relate to an earphone body part of which is inserted into the external auditory meatus. Those skilled in the art will realise that the present invention may be put into effect using a earphone body which is adapted to be located externally of the external auditory meatus, as opposed to being located at least partly in the external auditory meatus.
There may be more than one recess/passageway in the earphone body to allow for greater adjustment of the shape of the loop.
The front portion (sound tube) of the housing of the earphone of the fourth embodiment being made from Tungsten-Copper alloy could be made by any other material that allows the centre of gravity to be shifted towards the ear. For example, a more dense material such as an alloy with greater Tungsten content could be used. Tungsten metal could be used, as suggested in the fifth embodiment. Steel could be used. The front portion of the housing could be made from ultra lightweight material which could also assist in moving the centre of gravity towards the ear, and possibly requiring less dense material to be used in the front portion.

Claims

An earphone (1, 101) comprising:
an earphone body (2, 102) provided with a speaker (610, 810), the earphone body being adapted to be worn at least partly between, or internally of, the tragus and anti-tragus in the ear, and

a transmission cable (3, 103) connected to the speaker for the transmission of electrical signals to the speaker (610, 810),

characterised in that

the earphone comprises a loop (4, 104) of variable length and geometry formed at least in part by a part of the transmission cable, which, when the earphone body is in place, is adapted to be located at least partly in the concha (C) of the wearer and to engage the surface of the ear.
An earphone according to claim 1, wherein said part of the transmission cable comprises a cord, the cord being in the form of a sheath around the transmission cable, and being thicker than a region of the transmission cable not forming the loop.
An earphone according to claim 1 or claim 2, wherein the earphone body is provided with at least one loop guide for assisting in forming the loop (4, 104).
An earphone according to claim 3, wherein the loop guide is in the form of a passage (7) through, or a recess (107) for example a groove in, the earphone body.
An earphone according to claim 4, wherein the loop guide is in the form of a passage which extends completely through the earphone body.
An earphone according to claim 4 or claim 5, wherein the axis of the passage or recess is transverse to the axis of the earphone body.
An earphone according to any preceding claim comprising a means for fixing the length or shape of the loop (4, 104).
An earphone according to claim 7, wherein a part of the loop forms an interference fit with the loop guide thus fixing the length or shape of the loop (4, 104).
An earphone according to any preceding claim, wherein the loop defines a closed loop, said part of the transmission cable forming a part of the closed loop and a part of the earphone body forming a different part of the closed loop.
An earphone according to any preceding claim, wherein the earphone is so arranged that said part of the transmission cable is both configurable so as to form part of said loop (104) and configurable so that said loop is not formed.
An earphone according to any preceding claim, wherein the earphone body is adapted to be at least partly located in the external auditory meatus (M) of a wearer.
An earphone according to any preceding claim, wherein
the earphone body comprises a housing (105) which houses the speaker, and

the earphone body comprises a cushion (109), which is adapted to be worn in the external auditory meatus (M) of the ear.
An earphone according to any preceding claim, wherein the earphone is configured for use with an electronic audio device, such as an MP3 player, radio, digital versatile disk player or a compact disk player, particularly an electronic device carried on the person.
An earphone according to any preceding claim, wherein the transmission cable, which is connected at one end to the speaker (610, 810), is adapted at the opposite end for connection to an electrical sound output of an electronic audio device.
An earphone according to claim 14, wherein said opposite end of the transmission cable (3, 103) terminates with a connector, for example an audio jack.
An earphone set comprising a pair of earphones, at least one of which being an earphone according to any preceding claim.