A personal audio unit and manufacturing method thereof

Abstract

The earbud 1 comprises a shell 2 forming a housing for an electronics module and a sound driver. A nib 6 extends from the shell opening by 1 to 10mm so as to define a passage for transmission of sound from the sound driver to the ear of a user. The nib is arranged to support an earbud tip (8, fig 2) in use for seating in the user's ear. The shell 2 is formed of a first, harder material e.g., rigid nylon. The nib is formed of a second, softer material. The earbud tip may be softer than the nib. The nib may be elastomeric. This reduces the risk of the earbud being broken or damaged if mishandled Optionally an encapsulant material is provided at interstices between the electronics module and an internal surface of the shell. The encapsulant material may be introduced as a liquid and cured to form a solid encapsulant.

Description

Field of the Invention The present invention relates to personal audio units, and particularly, although not exclusively, to a resilient personal audio unit and a method of manufacture of a resilient personal audio unit. Background Personal audio units take many forms. At the most general, personal audio units provide sound directly to the ear(s) of a user, often taking the form of a unit that engages with the ear or a pair of units that engage with respective ears. The pair of units may be physically connected with each other, for example via a head- or neck-band, or via an interconnecting wire. The pair of units may be wirelessly interconnected with one another, for example via a Bluetooth connection. Portable audio units are directly connected to the ears or a user, either engaging with the ear, being retained against the ear, or a combination of the two. There is a risk that a portable audio unit can fall from the user’s ear(s). When this happens, there is a risk of damage to the portable audio unit housing or the various components located within. Portable audio units are generally small. They are easy to misplace. When misplaced they are at risk of again being inadvertently damaged, for example being stood on. A personal audio unit becoming disengaged I dislodged from the user’s ears is a particular risk during physical activity, for example during exercise, for example while running or while exercising at a gym, for example during “CrossFit” or powerlifting. Periods of physical activity may also coincide naturally with times when a dislodged portable audio unit is at risk of damage if dropped, for example being stepped on. It is important personal audio units are shock proof and resistance to impacts. Typical environments in which physical activity take place may also be potentially damaging to personal audio units, for example hard floors, muddy areas, puddles and the like. Furthermore, there is a need to have personal audio units that are resistant to damage via liquid ingress and / or dust or dirt ingress. For example, being waterproof, water resistant, or sweat proof is an important characteristic. During physical activity this is particularly true, when sweating is likely, or when swimming or showering, for example. Personal audio units typically have a protrusion for inserting into the user’s ear. The protrusion carries an earbud tip in use which can be selected to match the general size of the user’s ear, e.g. so that the tip can be partially inserted into the user’s ear canal. However it has been found that the quality of engagement with the user’s ear is often not ideal, e.g. varying from user to user, and an ill-fitting earbud or tip can lead to the personal audio unit being more likely to become dislodged in use. It has also been found that the protrusion causes a physical feature at which the personal audio unit can be damaged or broken. For example, the protrusion creates a point of stress concentration during impact or crushing of the unit and can lead to the shell / casing of the personal audio unit being more readily ruptured or damaged when mishandled. It is an aim of the present invention to resolve or mitigate one or more of the aboveidentified problems. Summary of the Invention According to a first aspect, there is provided a personal audio unit (PAU) having a rigid shell housing an electronics unit therein and a nib depending form the shell, wherein the nib is a resiliently deformable member and / or is formed of resiliently deformable material. According to a second aspect there is provided a PAU comprising a shell forming a cavity within the shell and an electronics module located within the cavity, wherein the cavity includes a solidified encapsulant contacting at least a portion of the electronics module and an internal wall of the shell. The PAU that may be resistant to damage. The present inventors have tested the PAU according to the present invention, and found that it performs well in impact resistance testing and weight drop testing. For example, the resilient nib can flex upon impact or application of excessive load to a greater degree than the shell and can therefore reduce a stress concentration due to its protrusion from the shell. This can help avoid damage to the PAU when excessive load is applied. The solidified encapsulant may improve the structural integrity of the shell. The solidified encapsulant may also improve the resistance to water I sweat and dirt I dust damage. Optionally, the shell is a substantially rigid shell or a rigid shell. The shell is rigid enough to maintain its shape in the absence of external forces. In some embodiments the shell is formed from a plastic material, for example a nylon material. The surprising benefit of the flexible / softer nib is that it may deform slightly upon application of smaller loads. For example, when inserted into the opening of the user’s ear canal the nib may adapt slightly to form a better fit. Additionally or alternatively, when the PAU is impacted accidentally when being worn by a user, it is less likely to cause damage to the user’s ear. Additionally or alternatively, when the user is undergoing vigorous exercise the flex in the nib may mean that it is less likely to become dislodged from the ear, e.g. being capably of flexing slightly to remain well seated in the user’s ear. Optionally, the electronics module comprises a power supply unit located within a cup, the cup being located within the cavity. In some embodiments the power supply unit includes a battery unit. Optionally, the cup is substantially surrounded by the encapsulant. In some embodiments, the inside of the cup, in which the power supply unit is located, is substantially free of encapsulant. Optionally, the cup is formed from a rigid material, for example a plastic. In some other embodiments, the cup is formed from a resilient material, for example a foam, for example a closed cell foam. The PAU may comprise a sound driver, e.g. a speaker, configured to provide sound to a user, wherein a sound emitting portion of the sound driver is exposed to a passage through the nib. In this way, a sound transmission passage, e.g. being air-filled or free of encapsulant, is provided. This may lead to improved audio performance and shock proofing. Optionally, a body portion of the sound driver is housed or coated in a flexible or elastic material, for example a latex or silicone. The flexible or elastic coating is located between the body portion of sound driver and the solidified encapsulant. The flexible or elastic coating may provide some cushioning between the sound driver and the solidified encapsulant. Optionally, the cavity is partitioned into an upper void and a lower void. Optionally, the encapsulant is located in the lower void, and the upper void is substantially free of encapsulant. The upper void may provide a location for electronic components that could be damaged by the encapsulant, or components with performance characteristics that could be worsened by the presence of the encapsulant. Optionally, the cavity is partitioned by a partition portion of the electronics module. In some embodiments, the partition portion of the electronics module is a circuit board. In this way, the number of components in the PAU may be reduced, since a PCB is acting as both a PCB (holding electronics components) and as a partition wall in the cavity. Optionally, an upper surface of the partition portion that faces into the upper void includes at least one user interface component. In some embodiments, at least one user interface component includes a switch for user control of the PAU. Optionally, the at least one user interface component includes a light for providing user feedback of an operation of the PAU. Optionally, the PAU includes at least one power electrical contact for charging the power supply unit, the at least one electrical contact being electrically connected to the electronics module. Wherein the PAU includes at least one data electrical contact for data transfer to and / or from the electronics module. Optionally, the electronics module includes a memory module for storing data for playback by the PAU. In this way, the PAU can be used for audio playback in the absence of a (e.g., wirelessly) connected data source, for example a mobile telephone. Optionally, the upper void is at least partially bounded by a flexible wall. The flexibility permits the user to deform the flexible wall to engage a switch within the PAU. Optionally, the PAU includes at least one support structure in the cavity to engage the electronics module. In this way, the electronics module is supported within the cavity during encapsulant introduction. In some embodiments, the PAU includes a plurality of such support structures. The electronics module may have an engagement feature to engage with a particular support structure. In this way, proper alignment of the electronics module within the cavity may be achieved. Optionally, the at least one support structure is an integrally formed part of the shell. In other words, the at least one support structure may be formed from the same material as the material of the shell. This may permit simpler manufacture. Optionally, the encapsulant is a potting compound. In some embodiments, the potting compound is a two-part epoxy resin. Optionally, the electronics module includes a wireless communication unit. In some embodiments, the wireless communication unit includes an antenna. In some embodiments, the antenna is exposed from the encapsulant, for example the antenna may be located within the upper void. Optionally, the PAU is an ‘earbud’ device. Optionally, the PAU is a hearing aid. Optionally, an external profile of the PAU is shaped for engagement with a user’s ear. The shell may be shaped / profiled to engage the outer ear of a user. The nib may depend therefrom for insertion into the end / opening of the ear canal of the user. According to a third aspect, a personal audio system is provided. The system includes a pair of PAUs, each PAU of the pair being according to the first or second aspect. Optionally, an external profile of a first of the pair is shaped for engagement with a user’s left ear, and an external profile of a second of the pair is shaped for engagement with a user’s right ear. According to a fourth aspect there is provided a method of manufacture of a PAU comprising: housing an electronics module in a shell, the electronics module comprising a sound driver and the shell shaped to enclose the electronics module and also defining an opening for sound transmission; attaching a nib to the shell at the opening such that the nib extends from the shell opening, the nib defining a passage for transmission of sound from the sound driver to the ear of a user, wherein the nib is formed of a resiliently deformable material that is softer than the shell and the nib is arranged to support an earbud tip in use for seating in the user’s ear. According to a fifth aspect, a method of manufacturing a personal audio unit, PAU, is provided. The method includes the steps of: forming a shell, the shell forming a cavity therein, the shell having a filling port into the cavity; locating an electronics module within the cavity; introducing a liquid encapsulant into the cavity via the filling port such that the liquid encapsulant enters interstices between the electronics module and an internal surface of the shell, and; curing the liquid encapsulant to form a solid encapsulant. Optionally the shell is a substantially rigid shell or a rigid shell. The shell is rigid enough to maintain its shape in the absence of external forces. In some embodiments the shell is formed from a plastic material, for example a nylon material. The opening of the fourth aspect may provide the filling port of the fifth aspect. The nib may be mounted to the shell or provided on the shell prior to introducing the liquid encapsulant. The nib may be shaped to receive the injector or nozzle for delivery of the liquid encapsulant. The nib may comprise a groove, e.g. outside the passageway. The nib may be generally tubular in form. Optionally, the shell includes a venting aperture. The method may include introducing a passage member through the venting aperture, a portion of the passage member being located within the cavity during liquid encapsulant introduction and during curing of the liquid encapsulant. Optionally, the method includes withdrawing the passage member after the curing of the liquid encapsulant, thereby forming a passage through the solidified encapsulant. Optionally, the electronics module includes a power supply unit, the passage being located between the venting aperture and the power supply unit. Optionally, forming the shell includes connecting at least two shell parts to one another, with the electronics module located within the cavity thereby formed. In some embodiments, an adhesive is provided between the connection point of at least two shell parts. Optionally, the method includes attaching the nib to the PAU, for example to the filling port. Optionally, the nib is configured for attachment to the ear canal engaging unit. The nib may comprise a retaining formation for engaging the shell, e.g. on the inside of the shell. The retaining formation may depend outwardly from the passageway or a tubular portion of the nib defining the passageway. The nib may comprise a plurality of retaining formations. The / each retaining formation may be spaced from a further formation of the nib for attaching an earbud tip in use. The nib may be adhered, fused or bonded to the shell, e.g. using an adhesive / glue. The nib may be irreversibly secured to the shell, e.g. in a manner that would require breaking of the shell or nib for its removal. Optionally the nib is configured for attachment to an ear canal engaging unit, e.g. an earbud tip. Optionally, the nib is shaped for attachment to an ear canal engaging unit. The nib may comprise a ridge, notch, recess or neck formation, e.g. towards its distal end. The optional or essential features described in respect of any single aspect may be applied to any further aspect wherever practicable. Summary of the Figures Working embodiments will now be discussed in further detail below by way of example only with reference to the accompanying figures, in which: Figure 1 shows an embodiment of a PAU; Figure 2 shows an alternative view of the embodiment of a PAU; Figure 3 shows an alternative view of the embodiment of a PAU; Figure 4 shows a schematic overview of an embodiment of a PAU system; Figure 5 shows a cross sectional view through an embodiment of a PAU; Figure 6 shows a further cross sectional view through an embodiment of a PAU; Figure 7 shows a cross sectional view through an alternative embodiment of a PAU; Figure 8 shows a plug in accordance with the present invention; Figure 9 shows a simplified cross-sectional view through an embodiment of a PAU; Figure 10 shows a view of a cap component for a PAU; Figure 11 shows a cross sectional view through an electronics module in accordance with an embodiment of a PAU; Figure 12 shows an overview of a method of manufacture in accordance with an embodiment of the present invention; Figure 13 shows a side view of a shell part for a further embodiment of a PAU; Figure 14 sows an above view of a shell part of Fig. 13; Figures 15a-c show respective isometric, side and bottom views of a nib for a PAU. Detailed Description of the Invention Figure 1 shows an earbud 1. Earbud 1 is an example of a personal audio unit according to the present invention. Other examples include an earphone, headphone, headset (for example a “Bluetooth headset”), a radio unit, for example a military radio (or earpiece portion thereof), and a hearing aid. The earbud 1 is formed from an external shell 2. The external shell 2 includes upper shell portion 3 and lower shell portion 4. The upper 3 and lower 4 shell portions are formed from a substantially rigid / hard material. The material of the shell 2 is a rigid plastic material, for example a rigid nylon material. In some embodiments, the material of the shell 2 is polyamide-12. In some other embodiments, the shell may be formed from a more flexible nylon. However the shell in all embodiments is generally inelastic and has a correspondingly high elastic modulus (modulus of elasticity). The elastic modulus of either or both shell portions may be at least 170 MPa, 180 MPA, 190 MPa or 200 MPa. The elastic modulus could be significantly higher. However in the examples described below, filling of the shell increases the strength / resilience of the earbud 1 and, as such, the rigidity of the shell material is less crucial. The hardness of the shell may be greater than 90, 95, 97 or 99 on the Shore A scale. The harness of the shell may be better measured on the Shore D scale, and the Shore D harness of the shell may be greater than or equal to 30, 40, 50, 60, 70 or 80. The shell is rigid enough to maintain its shape in the absence of external forces. The upper 3 and lower 4 shell portions are physically engaged with one another along shell interface 5. In embodiments, the upper 3 and lower 4 shell portions may be connected with one another using an adhesive (not shown). The shell 2 of the earbud 1 is shaped to sit snugly in the concha region of the user’s ear between the antihelix and the antitragus. It will be appreciated that some embodiments may not be so shaped. Some embodiments are shaped with a portion to hang around the outside of the user’s ear. In some embodiments, the PAU is retained against the user’s ear, for example via a headband attached to the personal audio unit. The earbud 1 includes a nib 6. The nib 6 is located on a side of the earbud 1 that is for engagement with the user’s ear. The nib 6 is for connection to an earbud tip (not shown in Figure 1). Accordingly, the nib 6 extends outwardly from the shell to provide a protrusion to which an earbud tip can be attached. The nib 6 in this example extends generally perpendicularly away from a flat outer surface portion of the shell. The nib 6 comprises a narrower neck formation 6A and a head formation 6B. The neck formation 6A is part way along the length of the nib 6 and the head formation 6B is at / towards the distal end of the nib. As such the neck formation 6A provides an annular groove or recess to which an earbud tip 8 can be attached for use. The nib extends from the outer surface of the shell by a length in the order of 1mm-10mm. Typically the axial length head formation 6B is at least, or of the order of, 1mm and the neck formation may also be at least, or of the order of, 1mm in length. Therefore the nib 6 may extend from the shell by greater than or equal to 2mm, e.g. greater than or equal to 2.5mm, 3mm or 3.5mm. The nib 6 preferably extends form the shell by less than 10mm, e.g. less than or equal to 8mm, 7mm, 6mm or 5mm. The nib 6 may extend inside the shell and so the total length of the nib may be longer than the portion of the nib that extends externally of the shell. The length of the nib extending inside the shell may be at least 1mm, 2mm or 3mm in length. The total nib length may therefore be less than or equal to 14mm, 12mm, 10mm or 8mm. The total nib length may be greater than 5mm or 6mm, e.g. being 7mm-8mm in length. The nib head formation 6B diameter may be 4-6mm, e.g. 4-5mm or 4.5-5mm. In this example, the nib head diameter is around 4.75mm. The nib neck formation 6A diameter may be 1mm-2mm less than the head diameter, e.g. around 1.3, 1.4 or 1.5 mm less than the head formation. This therefore defines the depth of the lip between the neck and head formations against which an earbud tip can be held in use. The earbud tip 8 (see Fig. 2) is formed from a flexible material for comfortable engagement with an outer portion of a user’s ear canal. The earbud tip 8 material may be softer than both the nib 6 material and shell 2, or shell portion 4, material. The earbud tip 8 may be formed of a conventional silicone, rubber or foam material. The engagement of the earbud tip with the user’s ear canal may provide sound isolation from external sounds. The earbud tip may be a user replaceable component. Furthermore, the user may select an earbud tip that is of a suitable size for their ear canal. This permits comfortable but secure connection of the earbud to the ear canal. The nib 6 is formed of a different material from the shell 2. The material of the nib 6 may be flexible or compliant. The nib may resiliently deform more readily than the shell, e.g. having a lower elastic modulus than the shell. The elastic modulus of the nib may be less than or equal to 150 MPa or 100 MPa, e.g. being less than or equal to 75 MPa or 50MPa. The elastic modulus of the nib may be at least an order of magnitude lower than that of the shell. The material of the nib 6 is more flexible or softer than the material of the shell 2. In some embodiments, the nib has a shore hardness of 88A. In various embodiments, the Shore A hardness of the nib may be less than 95 or 90 and could even be less than or equal to 85. The Shore A hardness of the nib is typically greater than 65, 70, 75 or 80. This provides it with sufficient rigidity to hold the earbud tip in use. The elongation at break, or elongation at yield, value for the nib may be greater than that for the shell, e.g. potentially being at least double, triple or an order of magnitude greater. The elongation at yield for the nib may be at least 10%, 20%, 30% or 40%. In some embodiments, the nib 6 is a separate, replaceable component from the shell 2. In some embodiments, the nib 6 is a separate component that is engaged with the shell 2 during manufacture, but the nib 6 is not user removable or replaceable. The nib 6 may comprise an engagement formation for engagement / abutment with the shell, e.g. to mechanically hold the nib in place in use. This may comprise a mechanical ‘keying’ or abutment formation. The engagement formation is typically provided at or towards a proximal end of the nib 6, e.g. to be held in the shell when assembled. Additionally or alternatively, the nib 6 may be bonded to the shell, e.g. by fusing or use of a suitable adhesive. In the embodiment of Figure 1, the nib 6 is a separate component that is physically engaged with the lower shell portion 4. To engage with the shell, the nib 6 includes a barb that engages with an edge of the shell 2 to retain the nib 6 in position. The shell portion 4 has a corresponding opening / port 20 as will be described below. In other embodiments, the nib 6 could be integrally formed with / onto a portion of the shell 2. For example, the nib may be moulded onto the shell in a two-shot moulding process or similar. The earbud 1 also includes a cap 7. The cap 7 covers an aperture formed in upper shell portion 3. The cap 7 is formed from a flexible material, for example a material that is more flexible than the material of the shell 2. In some embodiments, the cap 7 is formed from TPE (soft flexible filament). The cap is flexible to allow for a slight movement of the cap 7 material when pressed by a user. The cap 7 may comprise a material akin to the nib 6. In some embodiments, the cap 7 has a shore hardness of 88A. In some other embodiments, the cap 7 is formed of the same material as the remainder of the shell, e.g. where a softer material is not needed. In some embodiments, the cap 7 is integrally formed with the shell, or with the upper shell portion. In such embodiments, the flexibility of the material of the cap may be sufficient to permit the user interactions described below in respect of the (separate) cap 7. In such embodiments, the material that forms the cap I shell I shell portion may be thinned in the region of the cap, to increase cap flexibility in the cap region. As will be discussed later, the cap 7 permits user interaction with the electronics located within the earbud 1, for example controlling some operations of the earbud 1. The cap 7 is located on a side of the earbud 1 that is exposed when the earbud 1 is engaged with the user’s ear. In some embodiments, the nib 6 and the cap 7 are located on opposing sides of the earbud 1. In some embodiments, the nib 6 and the cap 7 are located on opposing sides of the shell 2. In some embodiments, the nib 6 is located within a first shell portion (e.g. the lower shell portion 4) and the cap 7 is located within a second shell portion (e.g. the upper shell portion 3). In some embodiments, the cap 7 is formed from a rigid material. Figure 2 shows an alternative view of the earbud 1. An earbud tip 8 is shown connected to the nib 6, which is not visible in Figure 2. Earbud tip 8 includes a sound passage 9, which permits the passage of sound from an audio unit (not shown in Figure 2), located within the earbud 1, to the user’s ear canal. The nib 6 also includes an internal passage as will be described below for passage of sound through the tip 8 via the nib 6. The internal passage of the nib 6 thus communicates the internal passage of the tip 8, e.g. such that the tip 8 can be seen as a generally tubular extension of the nib or its passageway. Earbud 1 includes three microphone holes 10 located in the cap 7 as shown in Figures 2 and 3. Three microphone holes 10 are exemplified, but the skilled person will readily appreciate that other embodiments may have more or fewer microphone holes, including a single microphone hole 10. The microphone holes 10 each include a microphone breathable membrane across the microphone hole 10. Each breathable membrane substantially prevents ingress of liquid and or dirt I dust from outside the earbud 1 through the microphone breathable membrane into the cavity inside the shell 2. The microphone holes 10 and microphone breathable membranes permit the passage of external sound to a microphone (not shown) located within the earbud 1. In some embodiments, a single membrane is provided to cover multiple microphone holes. This external sound may be utilised for example for conducting telephone calls, voice control, or for noise cancelling purposes. In some embodiments, the earbud 1 has no microphone and no microphone hole(s) 10. In some embodiments, the earbud 1 has a microphone, but does not have any microphone hole(s) 10. In such embodiments, sound may reach the microphone via transmission through the cap 7 and / or shell 2. In some embodiments, the earbud 1 includes more than one microphone, for example four microphones. The breathable membrane may be a waterproof and breathable membrane. Suitable breathable membranes are available from GORE. 2. In some embodiments, the breathable membrane may have a thickness between 0.1 and 1.0 millimetres, for example 0.25 millimetres. Figure 4 schematically illustrates the earbud 1 in the context of a personal audio system 11. The system 11 includes a pair of earbuds 1, a charging / carrying case 12, and a wirelessly connected compute device 13. Where the earbuds 1 are provided as a pair of earbuds 1, the earbuds 1 may be shaped as right and left earbuds 1, one of each. The right earbud 1 may be shaped as a mirror image of the left earbud 1, so that the left earbud 1 is configured for snug engagement with a user’s left ear and the right earbud 1 is configured for snug engagement with the user’s right ear. In other embodiments, the two earbuds 1 may be shaped substantially identically. In some embodiments, the earbuds 1 are labelled as “Left” and “Right” (or “L” and “R”). The pair of earbuds 1 may be configured to wirelessly communicate with each other. The wirelessly connected compute device 13 is configured to wirelessly connect with one or both of the earbuds 1. The wireless connection may be for the transmission of data from the compute device 13 to the earbuds 1 and from the earbuds 1 to the compute device 13. For example, the compute device 13 may transmit substantially real time sound data to the earbud(s) 1, which is then played back by one or both of the earbuds 1. In some embodiments, one or both of the earbuds 1 transmit sound data from the microphone unit in the earbuds 1 to the compute device 13. In some embodiments, the compute device 13 transmits sound data to one or both of the earbuds 1, which is then stored on one or both of the earbuds 1 for later playback (for example, when the wireless connection to the compute device 13 is unavailable). To this end, in some embodiments the earbud 1 includes a memory for data storage (for example, a RAM unit, for example a 4 gigabyte RAM storage unit). In some embodiments, the memory is configured to store audio data (for example, music or podcast content). In some embodiments, the wireless connection is a Bluetooth connection or a wi-fi connection. In some embodiments, the compute device 13 is one of a mobile phone, smart watch, computer, tablet computer, “phablet”, music I video player, or any other suitably configured device. In some embodiments the earbud 1 is both wirelessly connectable (for example via a Bluetooth connection) and includes a memory for data storage. In this way the earbud 1 is more flexible in its use cases, depending on the availability of a suitable compute device 13. The earbuds 1 can be housed within the charging / carrying case 12 when not in use. The charging / carrying case 12 includes a case power supply unit 14. When the earbuds 1 are located within the case 13, an electrical connection 15 between the earbuds 1 and the case power supply unit 14 is formed. The case power supply unit 14 thereby charges the power supply unit (not shown) within each earbud 1. Each earbud 1 may include a magnet (not shown). The magnet is configured to engage with a corresponding magnet or ferritic material in the charging I carrying case 12. The magnetic interaction between earbud 1 and case 12 retains the earbud 1 in place in the device and serves to provide precise alignment of the charging contacts of the earbud with the case power supply unit 14. Figure 5 shows a cross section through earbud 1. Figure 5 particularly illustrates the interface of the lower shell portion 4 with the nib 6. During manufacture, the nib 6 is pushed into the port 20, which is formed in the lower shell portion 4. The earbud tip 8 is engaged with the exposed, distal, end 21 of the nib 6, i.e. at the head formation 6B disclosed in relation to figure 1. The nib 6 includes a sound passage 22 formed therethrough. The passage permits the transmission of sound from a sound driver 23. The passage through the nib may have a diameter of greater than, or equal to, 1mm, 1,5mm, 2mm or 2.5mm or 3mm. The passage may be less than 5mm, 4mm or 3mm in diameter. The passage 22 may be approximately 2mm in diameter. The nib 6 in this example includes a breathable membrane 24 spanning the passage 22, which may be at its distal end 21. The breathable membrane 24 substantially prevents ingress of liquid and dust and dirt from outside the earbud 1 through the breathable membrane 24 into the cavity inside the shell 3, 4. The breathable membrane may be a waterproof and breathable membrane, and may be described as an acoustic vent material. Suitable breathable membranes are available from GORE, and other suppliers. In some embodiments, the breathable membrane may have a thickness between 0.1 and 1.0 millimetres, for example 0.25 millimetres. The breathable membrane may be perforated wherein the size of the perforations are sufficiently small to prevent water penetration, e.g. at defined pressure differences. The nib 6 may comprise a recess formation at its distal end to receive the breathable membrane 24. The recess formation may surround the passage 22 opening at the distal end of the nib. The membrane may be adhered to the nib 6 using a suitable adhesive. The breathable membrane 24 may be coated on at least one surface with an adhesive to aid watertight attachment of the breathable membrane 24 to the nib and or the housing. The breathable membrane 24 may also or alternatively be trapped and held in position between the nib and housing that engages with the nib. The sound created at the sound driver 23 passes along the sound passage 22, through the breathable membrane 24 and out of the aperture 9. At this point, the sound is transmitted into the user’s ear canal, which is engaged with the earbud tip 8. The port 20 in the lower shell portion 4 forms an inlet into the internal cavity 25 of the earbud 1. The port 20 may be slightly larger than the diameter of a shaft or body portion of the nib 6 and / or the head formation 6B. The port 20 may therefore closely surround the nib 6 when it is inserted / located therein. The proximal end of the nib 6 has an engagement formation 6C, which depends radially outwardly from the body portion of the nib to engage the inside of the shell portion 4. The engagement formation 6C is described above as a barb but could take the form of any suitable protrusion such as a flange or lip. The engagement formation could be annular, part-annular or a plurality of tabs angularly spaced about the passage 22. The internal cavity 25 of the earbud 1 houses a plurality of electronic components, which is an example of electronics module. These components may include any of: sound driver, power supply unit (e.g. battery), microcontroller, wireless connectivity module, switch for user input to the earbud 1, user feedback unit (for example, a light or series of lights). The electronic components inside the cavity 25 do not completely fill the cavity 25 formed by the shell 3, 4; some empty space remains. The switch(es) may constitute a multifunctional button that permits control of software running on the earbud 1 (for example, skip song, pause, activate a particular mode of operation). A liquid encapsulant is, during manufacture, introduced into the cavity 25. The liquid encapsulant is introduced via the port 20 in the shell, which forms a filling port. The liquid encapsulant substantially fills the spaces between the components that are located within the cavity 25. In other embodiments, a separate liquid introduction port may be included, for example at an interface or join between the shell components 3, 4. The liquid introduction port forms a filing port. In such embodiments, after liquid encapsulant introduction, a plug may be inserted into the aperture formed at the join between the shell portions. The plug may be inserted before the encapsulant solidifies. The plug may include a protrusion that extends into the liquid encapsulant. The liquid encapsulant solidifies around the protrusion, retaining the plug in place. In some embodiments, the protrusion is a hoop that extends into the liquid encapsulant. See Figures 7 and 8, for example. The present inventors have found that, regardless of liquid introduction aperture (via the nib aperture or another aperture) it is advantageous to have an internal surface of the shell that faces towards the aperture be generally inclined, and not flat during liquid introduction. In this way, it has been found that air pockets / bubbles remaining in the solidified encapsulant may be reduced. Reduction of air pockets I bubbles increases the strength of the finished PAU. In particular, the first surface that the initial portion of liquid encapsulant touches is inclined to the flat. This permits the liquid to flow naturally to a low point, and gradually fill and cover the lower surface. This may promote complete filling of the cavity. Figure 6 illustrates a fill level 26 of encapsulant into the earbud 1 via the port 20. The fill level 26 of the liquid encapsulant leaves the sound output portion of the sound driver 23 free from liquid encapsulant. The liquid encapsulant is injected between the gap between the output portion of sound driver 23 and the opening of the port 20. During encapsulant introduction, the opening of the sound driver 23 may be temporarily blocked, to prevent any inadvertent introduction of liquid encapsulant into the sound driver 23. Regardless of its insertion method, the liquid encapsulant, after introduction into the cavity 25 hardens into a solid encapsulant during a curing step. The hardened encapsulant, which is in close conformity with components inside the earbud, protects those components from damage from, for example, vibration and shock. The hardened encapsulant also increases the structural integrity of the shell 3, 4. The earbud 1 is thereby strengthened and resistance to catastrophic failure from, e.g. crushing forces, is improved. The encapsulant also increases the water and sweat and dust I dirt resistant of the earbud 1. In some embodiments, the body of the sound driver may be housed or coated in a flexible or elastic material, for example a latex or silicone. Once the encapsulant hardens around the coated sound driver body, the flexible or elastic material may provide cushioning to the sound driver 23, permitting slight movement between sound driver 23 and the earbud 1. This may improve sound performance. In some embodiments, the shell 3, 4 includes a pressure equalisation aperture. The pressure equalisation aperture allows the pressure inside the shell to equalise during liquid encapsulant introduction. This may assist with ensuring the liquid encapsulant intrudes into all intended voids / interstices in the cavity. In some embodiments, the encapsulant is a potting compound, for example a low viscosity potting compound. In some embodiments, the encapsulant, in its liquid form, is a molten polyamide compound. In some embodiments, the encapsulant is a two-part epoxy resin. In some embodiments, once cured, the encapsulant has a Shore hardness of 84D. In some embodiments, the encapsulant may be an electric grade 832 series epoxy. In some embodiments, the combining of the two parts of the epoxy resin may lead to an exothermic reaction. The temperature of the liquid encapsulant may therefore rise slightly. In turn this may decrease a viscosity of the liquid encapsulant. In turn this may improve a filling factor of the liquid encapsulant, making it easier to fill all available space in the cavity 25. In some embodiments, the temperature of the liquid encapsulant is less than around 50 degrees Celsius, for example, around 35 degrees Celsius. In this way, damage to electronic components from heat, for example, the power supply unit, may be avoided. Figure 7 shows an alternative embodiment of PAU 1. In this embodiment, the liquid encapsulant is introduced into the cavity 25 via an aperture 25A formed at the join line between the shell portions 3, 4. In such embodiments, after liquid encapsulant introduction, a plug 25B is inserted into the aperture 25A. The plug (see Figure 8) is engaged with the aperture 25A after the encapsulant is introduced to the cavity 25, and before the encapsulant solidifies. The plug 25B includes a protrusion 25C that extends into the liquid encapsulant. The liquid encapsulant solidifies around the protrusion 25C, retaining the plug 25B in place. In some embodiments, the protrusion 25C is a hoop that extends into the liquid encapsulant. The protrusion of the plug 25B extends below the fill level 26 of the liquid encapsulant. The plug 25B may include a label indicating as “Left” and “Right” (or “L” and “R”) for the respective PAU 1 into which the plug 25B is engaged. Figure 7 also illustrates the lower internal surface 25D of the cavity 25. The lower internal surface 25D of the cavity 25 is the internal surface of the cavity 25 that opposes the opening via which the liquid encapsulant is introduced. In the embodiment of Figure 7, this is the aperture 25A. The lower internal surface 25D is generally inclined, and not orientated flat. This inclination may be achieved by orientating the PAU 1 during liquid encapsulation introduction, and or via the shape of the internal surface. In this way, it has been found that air pockets I bubbles remaining in the solidified encapsulant may be reduced. Reduction of air pockets I bubbles increases the strength of the finished PAU. In particular, the first surface that the initial portion of liquid encapsulant touches (the lower internal surface 25D) is inclined to the flat. This permits the liquid encapsulant to flow to a low point on the lower internal surface, and gradually fill and cover the lower internal surface 25D. The cavity is then subsequently filled with liquid encapsulant. The inclined lower internal surface 25D may promote complete filling of the cavity 25 with liquid encapsulant. Figure 7 also illustrates an alternative location for the breathable membrane 24. The breathable membrane 24 substantially prevents ingress of liquid and dust and dirt from outside the earbud 1 through the breathable membrane 24 into the cavity inside the shell 3, 4. The breathable membrane may be a waterproof and breathable membrane. Suitable breathable membranes are available from GORE, and other suppliers. In some embodiments, the breathable membrane may have a thickness between 0.1 and 1.0 millimetres, for example 0.25 millimetres. The breathable membrane 24 may be coated in an adhesive to aid watertight attachment to the nib and or the housing. In the embodiment of Figure 7 the breathable membrane 24 is retained and held in position between the nib 6 and housing that engages with the nib 6. Such retention and holding may also aid watertight engagement. Figure 7 also illustrates that the shell portion that engages the driver 23 includes a driver engagement socket 23A sized and shaped to engage a least a sound transmission portion of the driver 23. The driver engagement socket 23A may be sized to accommodate a driver 23 that is coated in a resilient material, for example a latex or silicone. The driver 23 may be engaged with the driver engagement socket 23A prior to the introduction of liquid encapsulant. This may protect the sound transmission portion of the driver 23 from coming into contact with the liquid encapsulant. Returning to the embodiment of Figure 5, the battery 27 is located within a cup 28. The cup 28 may be sealed around the peripheral edge to a PCB of the electronics component, thereby forming a battery cavity inside the cup 28. The battery 27 is thereby separated from the encapsulant. The cup 28 is formed from a rigid plastic material. In some other embodiments, the cup 28 may be formed from a foam, for example, a closed cell foam. In some embodiments, the cup 28 closely conforms to the shape of the battery 27. In some other embodiments, the cup 28 has a peripheral wall that is shaped to permit a flat landing zone on the PCB to be formed to which the cup 28 is attached. For example, the shape of a peripheral edge of the cup 28 may be designed to permit a flat landing zone on the PCB to which the cup 28 is attached to be formed, where the landing zone is substantially absent of electronic components. In some embodiments, this means that a peripheral wall of the cup 28 has a non-circular shape. In some other embodiments, the cup 28 is omitted. Figure 9 illustrates a simplified illustration of earbud 1, in which most of the internal electronics module is omitted for explanation purposes. Within the cavity 25, two voids are formed: a lower void 29 and an upper void 30. The lower and upper voids 29, 30 are partitioned by an interface printed circuit board (PCB) 31. The interface PCB 31 is part of the electronics module. In other embodiments, a different component or a dedicated wall component may be used to partition the cavity 25. The interface PCB 31 is mounted within the cavity 25 to but against a peripheral shoulder 32 formed on an internal surface of the upper shell portion 3. The connection between the shoulder 32 and the PCB 31 may substantially prevent the passage of the liquid encapsulant from the filling port 20 into the upper void 30. In some embodiments, the lower and upper voids 30, 29 are substantially hermetically sealed from each other by the interface PCB 31. A surface of shoulder 32 includes a channel 33 formed therein (for example a scalloped channel). The channel 33 may form a continuous loop around the shoulder 32. During manufacture a sealant may be introduced into the channel 33. The sealant may assist in forming a hermetic seal between the PCB 31 and the shoulder 32. The sealant may be a silicone. In some embodiments, an adhesive may be used in place of a sealant. In some other embodiments, a combined adhesive and sealant may be used. The cap 7 may bound a portion of the upper void 30. The face of the interface PCB 31 that faces into the upper void 30 includes electronic components with which the user interacts directly. These components may include, but are not limited to, any of: one or more switches, one or more lights, at least the sound responsive part of the microphone unit, and at least a portion of a wireless communication antenna. Figure 10 shows the cap 7. The internal surface of the cap 7 includes an interface projecting portion 40. When the cap 7 is connected to the earbud 1, the interface projecting portion 40 protrudes into the upper void 30. The interface projection portion 40 is sized and shaped for engagement with a switch located in the upper void 30. This may reduce the travel necessary of the cap 7 before the switch is activated by a user pressing on the cap 7. Figure 11 shows an electronics module 50 in accordance with an embodiment. The electronics module 50 is formed from three flexibly interconnected printed circuit boards (PCBs): the interface PCB 31, the primary PCB 51 and the charging PCB 52. In other embodiments, the electronics module 50 of the earbud 1 may take a different form, for example more or fewer PCBs, e.g. as a single PCB. The thickness of a PCB substrate may be between 0.2 and 1.5 millimetres, for example 1 millimetre. Components mounted to the PCB substrate may increase the thickness of the electronic module. The PCB substrate may be a Glass Fiber Epoxy Laminate, or “FR4”. The PCB substrate could be a multilayer substrate, for example, a 2-layer, 4, layer, 6-layer, or 8-layer PCB substrate, or it have an odd number of layers. The battery 27 is electrically connected to the primary PCB 51. The battery 27 is an example of a power supply unit. As above, in some embodiments, the battery is located within a cup 28 (see Figure 5). The battery 27 is electrically connected to the electrical charging contacts 34 on the charging PCB 52. The electrical contacts are exposed via a pair of apertures in the lower shell portion 4, when the electronic module is installed in the shell 2. The charging PCB 52 also includes a pair of data contacts (not shown). The data contacts are also exposed via a pair of apertures in the lower shell portion 4, when the electronic module is installed in the shell 2. The two data contacts and the two electrical contacts may be arranged at the four corners of a square on the lower shell portion 4. In some embodiments, the electrical contacts may have dual functionality - used for both charging and data transfer. A method of manufacture 60 of the PAU, e.g. earbud 1, will now be described. As shown in Figure 10, the method 60 includes a shell formation step 62. During the shell formation step 62 the upper and lower shell portions 3, 4 are formed. The shell formation 62 may include moulding the shell portions 3, 4. The shell portions 3, 4 may be formed from the same rigid moulded plastic material as described above. Alternatively, only the shell portion 4 is formed of that material. In an electronics module formation step 64, the electronic components that are to be housed within the shell (described above) are electronically / electrically connected to one another to form the electronics module. Forming the electronics module as a single unit for housing in the shell 3, 4 may improve the manufacturability of the earbud 1. A shell closure step includes connecting the upper and lower shell portions 3, 4 with the electronics module located within the cavity 25. At the mutual connection point of the upper and lower shell portions 3, 4 an adhesive is applied prior to connection of the upper and lower shell portions 3, 4. The method 60 optionally further includes a cap attachment step 68. In this step the flexible cap 7 is attached to an aperture formed in the upper shell portion 3. At the mutual connection point of the upper shell portion 3 and the cap 7 an adhesive is applied prior to connection. In some embodiments, the cap attachment step 68 is performed after the encapsulant introduction step 72 and the curing step 74. The method 60 includes a vent passage formation step 70. In this step, a pin is introduced through a venting aperture through the shell. The pin is left in situ during the encapsulant introduction step 72 and the curing step 74 (see below). After the curing step 74, the pin is withdrawn. A venting passage is thus formed between the battery 27 and the environment. In embodiments in which the battery 27 is located within cup 28, the venting passage may extend to the inside of the cup 28. The venting passage may include a venting passage breathable membrane, e.g. of the type described above in relation to membrane 24. In other embodiments, the venting passage and its formation step 70 are omitted. In the encapsulant introduction step 72 an encapsulant liquid is introduced into the voids within the cavity 25 formed by the shells 3,4. The liquid encapsulant may contact at least a portion of the electronics module and an internal surface of at least the lower shell portion. The liquid encapsulant may be introduced into the cavity under pressure. This may assist with ensuring the liquid encapsulant intrudes into all intended voids within the cavity within and around the electronics module. Between 3 and 30 grams of liquid encapsulant may be introduced into a single PAU. For example, between 5 and 20 grams of liquid encapsulant, for example between 8 and 15 grams of liquid encapsulant, for example approximately 10 grams of liquid encapsulant. During the introduction of the liquid encapsulant into the cavity, the earbud 1 may be vibrated in a vibration step. This may assist with ensuring the liquid encapsulant intrudes into all intended voids in the cavity. This may also mitigate the presence of air bubbles or air pockets within the liquid encapsulant. The vibration step may happen during or after the encapsulant introduction step 62. In some embodiments, the liquid encapsulant is introduced into the cavity via the port 20. The liquid encapsulant may be introduced between the sound driver and edge of the port 20. The fill level of the liquid encapsulant leaves the sound output portion of the sound driver 23 free from liquid encapsulant. The liquid encapsulant may be injected into the gap between the output portion of sound driver 23 and the opening of the port 20. During encapsulant introduction, the opening of the sound driver 23 may be temporarily blocked, to prevent any inadvertent introduction of liquid encapsulant into the sound driver 23. In other embodiments, the liquid encapsulant may be introduced into the cavity via a different aperture in the shell 3, 4, or via an aperture formed by the nib 6 (as will be described below). In such embodiments, after liquid encapsulant introduction, a plug may be inserted into the aperture formed at the join between the shell portions as described above. In some embodiments, the shell 3, 4 includes a pressure equalisation aperture. The pressure equalisation aperture allows the pressure inside the shell to equalise during liquid encapsulant introduction. This may assist with ensuring the liquid encapsulant intrudes into all intended voids in the cavity. The pressure equalisation aperture may be closed after the encapsulant introduction step 72. The method 60 further includes a curing step 74 whereby the liquid encapsulant within the shell cavity hardens into a solid. The curing step 74 may include holding the earbud 1 substantially motionless for at least a predetermined curing time. The predetermined curing time may be between 30 mins and 24 hours. The liquid encapsulant may have a setting time of around 60 minutes. Additionally or alternatively, the setting time may be modified by heating or use of a UV curable material. The method 50 optionally includes a closing step 76 for closing the port 20 via which the encapsulant was introduced into the cavity. In embodiments in which the encapsulant is introduced via the port 20, the closing step 76 may include attaching the nib 6 to the port 20. The closing step 76 may occur before, during or after the curing step 74. Turning now to Figures 13-14, there is shown further details of a housing part 100 to which a flexible nib may be attached. An embodiment of a nib 102 to be engaged with the housing 100 is shown in Figure 15. The nibs 6 and 102 described herein may be used with encapsulated earbud arrangement 1 described herein or else may be used with a different earbud embodiment where the PAU is assembled in a more conventional manner (without encapsulation). The housing part 100 has a port 20 of the type described above to receive the nib 102. In Figure 14, there can be seen engagement formations 104 about the port 20 corresponding to engagement formations (e.g. projections) 106 of the nib 102. The engagement formations 104 take the form of one or more recess or receiving formation in the inside of the housing to receive one or more projection of the nib. Thus the nib can be inserted into the port 20 form behind and the engagement formations 106 can engage in the receiving formations 104 so the nib 102 is held correctly in place. The housing also comprises a venting opening 108 for venting air during filling of the shell as described above. The opening 108 may be filled completely or plugged once the shell cavity has been filled, or may be absent if encapsulation of the earbud is not used. The nib 102 comprises a body portion 110, which may be generally cylindrical or slightly tapered so as to be frustoconical. The above-described neck 6A and head 6B formations are provided at a distal end of the nib 102 and / or its body portion 110. The neck 6A is narrower than the body portion 110. The body portion 110 width / diameter may be substantially equal to, or slightly greater than, the head portion diameter. Any dimensions of the nib may be as previously described above. The sound passage 22 passes through the nib 102 in an axial direction. At the proximal end of the nib, one or more engagement formation 106 is provided. In this example, projecting formations 106 extend radially outwardly from the body portion 110. The projections are in the form of discrete tabs and may be wedge shaped. The engagement formations 106 are angularly spaced about a central / longitudinal axis of the nib 102, e.g. equally spaced about the periphery of the body portion 110. Two or more engagement formations 106 may be provided. Three projections are provided in this example, e.g. with one being a different / shallower projection than the other two, which are diametrically opposite each other. As can be seen in Figures 15b and 15c, an engagement formation 106 is absent on one side of the nib 102 and instead there is provided a groove 112. A groove 112 is provided along the nib 102 in the axial direction, e.g. along the body portion 110 and / or head formation 6B. The groove 112 in this example provides an injection site / port for the encapsulation of the internal cavity of the PAU as described above. The internal cavity 25 of the PAU can be filled up to a level during encapsulation so that the proximal end of the nib 102 with the engagement formations 106 is submerged or partially submerged in the encapsulant. This avoids the need for adhesive, i.e. since the encapsulant fixes the nib 102 in place in the port 20 of the housing part 100. However, in other examples, an adhesive may be used to fix the nib in place (e.g. where encapsulation is not used) or the encapsulant may be considered to act as an adhesive. A recess 114 is provided in the proximal end of the nib 102, e.g. in the end face thereof, as shown in Figure 5c. The recess 114 is shaped to receive the sound driver 23 (see Figs. 5-7 above). The recess may closely receive the sound driver so that it is a snug / friction fit. The sound passage 22 opens into the recess 114. In this example, the recess is rectangular in section to match the profile of the sound drive but it could be other geometric shapes as necessary. The end of the sound driver 23 may be effectively sealed in the recess 114 so that encapsulant cannot enter the recess during filling. Additionally / alternatively, the recess 114 height may be sufficient such that the end of the sound driver 23 is above the filling level during the encapsulation process. The nib 102 has a further / shallow recess 116 in its distal end to receive a membrane 24 of the type described above. In view of the examples of the nib 6 and 102 described above, it will be appreciated that the nib can be beneficially made of a different, softer material than the shell of the PAU and can be fixed in place relative to the port 20 of the shell. The nib can thus resiliently deform in use in a manner that the shell itself cannot, which carries a plurality of potential benefits for the PAU as described above. The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof. Ranges may be expressed herein as from “about” or “around” one particular value, and / or to “about” another particular value. When values are expressed as approximations, by the use of the antecedent “about” or “around” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example + / -10%.

Claims

1. A personal audio unit (PAU) comprising:a shell forming a housing for an electronics module comprising a sound driver, the shell having an opening for sound transmission;a nib extending from the shell opening by a distance of 1-10mm, the nib defining a passage for transmission of sound from the sound driver to the ear of a user, the nib arranged to support an earbud tip in use for seating in the user’s ear;wherein the shell is formed of a first, harder material and the nib is formed of a second, softer material.

2. The PAU of claim 1, wherein the nib comprises a resiliently deformable or flexible material.

3. The PAU of claim 1 or 2, wherein the nib comprises an elastomer or thermoplastic elastomer4. The PAU of any preceding claim, wherein the nib comprises TPU.

5. The PAU of any preceding claim, wherein the nib comprises a hardness of less than 100, 95 or 90 on the Shore A hardness scale.

6. The PAU of any preceding claim, wherein the nib comprises a hardness of between 75 and 90 on the Shore A hardness scale7. The PAU of any preceding claim, wherein the nib has a hardness on the Shore Ascale whereas the shell has a harness value on the Shore D scale.

8. The PAU of any preceding claim, wherein a difference in hardness between the nib and shell is at least 10, 15 or 20 on the Shore A or Shore D hardness scale.

9. The PAU of any preceding claim, wherein the shell has a hardness of 50, 60, 70 or more on the Shore D hardness scale.

10. The PAU of any preceding claim, wherein the nib has a lower elastic modulus than the shell.

11. The PAU of any preceding claim, wherein the nib has a higher elongation at yield than the shell.

12. The PAU of any preceding claim, wherein the nib is arranged to removably receive an earbud tip in use.

13. The PAU of any preceding claim, the nib comprising an attachment formation for an earbud tip at its distal end.

14. The PAU of claim 13, wherein the nib comprises a neck formation and a head formation of greater width than the neck formation, the head and neck formations acting as the attachment formation for engagement by the earbud tip in use.

15. The PAU of any preceding claim, comprising the earbud tip, wherein the earbud tip is softer or more flexible than the nib.

16. The PAU of any preceding claim, wherein the nib extends beyond the shell by a distance of 1mm-10mm.

17. The PAU of any preceding claim, wherein the nib extends beyond the shell by a distance of 2mm-8mm.

18. The PAU of any preceding claim, wherein the nib extends into the shell by a distance of 1mm-5mm.

19. The PAU of any preceding claim, wherein the nib comprises a width or diameter of 4-8mm and / or wherein the port of the shell comprises a width or diameter of 4-8mm.

20. The PAU of any preceding claim, wherein the nib passage comprises an internal diameter or width of 1-4mm.

21. The PAU of any preceding claim, comprising an engagement formation for engagement between the nib and the shell.

22. The PAU of claim 21, wherein the engagement formation is spaced from the distal end of the nib and / or attachment formation of the nib.

23. The PAU of any preceding claim, wherein the nib comprises a recess in a proximal end thereof, the recess arranged to receive the sound driver of the electronics module.

24. The PAU of any preceding claim, wherein the nib comprises a groove in a side thereof, the groove arranged to define an opening space between the side of the nib and the port of the shell.

25. A method of manufacturing a PAU, comprising:providing a shell defining a housing for an electronics module comprising a sound driver in use, the shell having an opening for sound transmission;affixing a nib to the shell extending from the shell opening by a distance of at least 1mm, the nib defining a passage for transmission of sound from the sound driver to the ear of a user, wherein the nib comprises a formation arranged to support an earbud tip in use for seating in the user’s ear;wherein the shell is formed of a first, harder material and the nib is formed of a second, softer material.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS:Claims:

1. A personal audio unit (PAU) comprising:a shell forming a housing for an electronics module comprising a sound driver, the5 shell having an opening for sound transmission;a nib extending from the shell opening by a distance of 1-1 Omm, the nib defining a passage for transmission of sound from the sound driver to the ear of a user, the nib arranged to support an earbud tip in use for seating in the user’s ear;wherein the shell is formed of a first, harder material and the nib is formed of a10 second, softer material; and,wherein the PAU comprises the earbud tip, wherein the earbud tip is softer or more flexible than the nib.

2. The PAU of claim 1, wherein the nib comprises a resiliently deformable or flexible 15 material.CM3. The PAU of claim 1 or 2, wherein the nib comprises an elastomer or thermoplastic elastomerCM 20 4. The PAU of any preceding claim, wherein the nib comprises TPU.

5. The PAU of any preceding claim, wherein the nib comprises a hardness of less than 100, 95 or 90 on the Shore A hardness scale.25 6. The PAU of any preceding claim, wherein the nib comprises a hardness ofbetween 75 and 90 on the Shore A hardness scale7. The PAU of any preceding claim, wherein the nib has a hardness on the Shore A scale whereas the shell has a harness value on the Shore D scale.

308. The PAU of any preceding claim, wherein a difference in hardness between the nib and shell is at least 10, 15 or 20 on the Shore A or Shore D hardness scale.

9. The PAU of any preceding claim, wherein the shell has a hardness of 50, 60, 70 or 35 more on the Shore D hardness scale.24 09 2410. The PAU of any preceding claim, wherein the nib has a lower elastic modulus than the shell.

11. The PAU of any preceding claim, wherein the nib has a higher elongation at yield 5 than the shell.

12. The PAU of any preceding claim, wherein the nib is arranged to removably receive an earbud tip in use.10 13. The PAU of any preceding claim, the nib comprising an attachment formation foran earbud tip at its distal end.

14. The PAU of claim 13, wherein the nib comprises a neck formation and a head formation of greater width than the neck formation, the head and neck formations acting 15 as the attachment formation for engagement by the earbud tip in use.

15. The PAU of any preceding claim, wherein the nib extends beyond the shell by a distance of 1mm-10mm.20 16. The PAU of any preceding claim, wherein the nib extends beyond the shell by adistance of 2mm-8mm.

17. The PAU of any preceding claim, wherein the nib extends into the shell by a distance of 1mm-5mm.2518. The PAU of any preceding claim, wherein the nib comprises a width or diameter of 4-8mm and / or wherein the port of the shell comprises a width or diameter of 4-8mm.

19. The PAU of any preceding claim, wherein the nib passage comprises an internal 30 diameter or width of 1 -4mm.

20. The PAU of any preceding claim, comprising an engagement formation for engagement between the nib and the shell.35 21. The PAU of claim 20, wherein the engagement formation is spaced from the distalend of the nib and / or attachment formation of the nib.24 09 2422. The PAU of any preceding claim, wherein the nib comprises a recess in a proximal end thereof, the recess arranged to receive the sound driver of the electronics module.5 23. The PAU of any preceding claim, wherein the nib comprises a groove in a sidethereof, the groove arranged to define an opening space between the side of the nib and the port of the shell.

24. A method of manufacturing a PAU, comprising:10 providing a shell defining a housing for an electronics module comprising a sounddriver in use, the shell having an opening for sound transmission;affixing a nib to the shell extending from the shell opening by a distance of at least 1 mm, the nib defining a passage for transmission of sound from the sound driver to the ear of a user, wherein the nib comprises a formation arranged to support an earbud tip in15 use for seating in the user’s ear, wherein the shell is formed of a first, harder material and the nib is formed of a second, softer material;supporting the earbud tip on the formation, wherein the earbud tip is softer or more flexible than the nib.

Images