Receiver for use in ear canal

Abstract

The present invention relates to a receiver for use in an ear canal of a person, a receiver housing for use in such receiver and a receiver in canal assembly, wherein the receiver comprises a receiver housing having a sound outlet in acoustic communication with a front volume within the receiver housing; a diaphragm arranged within the receiver housing, separating the front volume and a rear volume within the receiver housing, wherein at least part of the diaphragm is configured to vibrate in response to a drive signal applied to a voice coil positioned in the rear volume; and a magnetic motor configured to generate a static magnetic field in a space within which at least part of the voice coil is positioned; wherein at least the part of the housing that is designed for direct contact with an ear canal, is made of a biocompatible material and / or the residual acoustic rear volume is at most 15 mm3; the combined acoustic mass of the diaphragm and voice coil is at most 130000 kg / m4; and the product of (combined acoustic mass of diaphragm and voice coil) times the residual acoustic rear volume is in the range of from 3.0E-4 to 9.5E-4 kg / m.

Description

[0001] RECEIVER FOR USE IN EAR CANAL

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a receiver for use in an ear canal of a person, a voice coil for use in such receiver and a receiver in canal assembly.

[0004] BACKGROUND OF THE INVENTION

[0005] Within the hearing aid industry, the shape and dimensions of the hearing aid components forming the hearing aid devices are of great importance as these components need to fit into the hearing devices, such as hearing devices being at least partly positioned in the ear canal of the user of the hearing device. An example of such a hearing device is the In-The-Ear (ITE) hearing aid.

[0006] With respect to ITEs the shape and dimensions of the receiver are of particular importance in that the receiver needs to fit into the nozzle of the hearing device. In the hearing aid industry, the term "receiver" is commonly used to refer to a sound generating device, i.e. a speaker.

[0007] Hearing devices such as ear pods, headphones, mobile phones and the like typically include so-called dynamic speakers, wherein a linear motor is used to move a cone-shaped diaphragm. A drive signal, alternating current, is applied to a voice coil connected to the diaphragm. The voice coil moves axially in a cylindrical gap containing a magnetic field produced by a permanent magnet, due to Faraday's law of induction. This causes the diaphragm to move in air, causing sound waves. The dynamic speaker, moving coil, was first invented in 1898 and further improved in 1925, see US patent specification No. 1,707,570, which is still the same moving coil principle used in dynamic speakers today and is characterized by a relatively flat frequency response.

[0008] The rear of the speaker must be contained in a housing, to ensure that sound waves emanating from the rear of the diaphragm do not cancel out sound waves emanating from the front of the diaphragm. The rear volume is a closed volume which, consequently, has a certain stiffness. The larger the volume, the lower the stiffness. There is a direct relation between the stiffness and the output of the receiver, which means that the larger the rear volume, the lower the stiffness, the higher the sound output.

[0009] Although such dynamic speakers are, by far, the most common type of speakers used today, in contrast, in the hearing aid industry, balanced armature driver-based receivers are by far the most in use today. Balanced armature-based receivers and moving coil based receivers (dynamic speakers) use different technology principles for producing sound pressure and they differ in construction. The armature (a metal strip) in a balanced armature receiver is placed between two magnets and a fixed, non-moving, coil is placed around the armature. The armature tip is positioned exactly in the centre between two magnets (balanced armature). Current through the coil will inject flux into the armature, setting it in motion. A drive pin connected to the armature on one end moves a diaphragm on the other end producing sound pressure which is let out via a sound outlet.

[0010] Balanced armature drivers offer substantially more output per mm3and are more efficient in transforming electrical energy into sound. This means that balanced armature receivers are inherently smaller and use less power for the same or higher output, same or higher Sound Pressure Level (SPL) in dB. For example, a 4100 single balanced armature receiver marketed by Sonion A / S as the world's smallest has dimensions of 0.98 x 2.70 x 5.00 mm; a total volume of 13.2 mm2and a maximum peak output of 113 dB. The 2600 series balanced armature receiver, marketed by Sonion A / S, has dimensions of 5.25 x 3.05 x 2.55 mm; a total volume of 41 mm3; and a maximum peak output of 126 dB. The latter dimensions are sufficiently small to enable us in In the Ear (ITE) and Completely in the Canal (CIC) applications as they fit into the ear canal of a significant proportion of hearing-impaired persons, in other words, the 'fit rate' is typically above 90%. Knowles Corporation for example markets a RAB-32037-000 receiver for use in receiver in canal (RIC) applications having dimensions of 5.28 x 2.96 x 2.58 mm; a total volume of 40 mm3; and a maximum peak output of 118 dB .Larger balanced armature receivers, such as the 1900 receiver marketed by Sonion A / S, having dimensions of 7.95 x 5.60 x 4.07 mm, at a total volume of 181.2 mm3and a maximum peak output of 138 dB, are more suitable for use in so called Behind the Ear (BTE) hearing devices as, for most people, the dimensions are too large to fit into the ear canal.

[0011] As reported by Knowles Corporation, the volume of the smallest dynamic speaker is still more than double the size of a typical balanced armature receiver.

[0012] Despite the many advantages of balanced armature receivers as compared with dynamic speakers, there are also some disadvantages. Balanced armatures are more sensitive to mechanical shock than dynamic speakers (moving coil receivers). With receivers being one of the more shock sensitive components in hearing aids, there is a desire to improve shock resistance. Also, the output of balanced armature receivers is inherently non-linear relative to the driving signal, whereas the output of moving coil receivers is inherently linear. A linear output can be advantageous for example if the hearing aid includes advanced signal processing features such as Active Noise Cancelling (ANC). Further, due to lower distortion, the sound quality of moving coil receivers is generally better, resulting in a better user experience when listening to music. A moving coil receiver is also generally easier to manufacture and contains less components as compared with a balanced armature receiver.

[0013] US2021 / 0360350 describes a planar coil, secured to a diaphragm where the windings are arranged in the same plane, i.e. parallel to, the diaphragm. A plurality of permanent magnets are arranged in the rear volume below the planar coil. The volumetric efficiency of such a planar arrangement leaves much to be desired and is therefore not effective for use for receivers for in ear canal applications such as hearing aids.

[0014] US2008 / 044044 describes a dual moving coil speaker. According to the patent specification, dimensions may be smaller than 20 x 10 x 6 mm, such as a cylindrical housing in the range of 3-6 mm, with a height of 4-6 mm, making it generally unsuitable for use in the ear canal of a person. To reduce the size of the dual moving coil speaker, a first receiver housing portion of the dual moving coil speaker is magnetically conductive, which is generally not a biocompatible material. Further, there is still a need for further improvement in terms of efficiency and more closely matching the performance of balanced armature receivers.

[0015] DESCRIPTION OF THE INVENTION

[0016] It would be desirable to provide a receiver that combines the advantages of a balanced armature receiver with a moving coil receiver, that is a receiver that has limited power consumption; has dimensions that allow it to fit into the ear canal of a person, that preferably has a fit rate of more than 90% of adults; has a more linear output, lower distortion, a peak output typically in the range of from 2500 - 3000 Hz to compensate for an open ear canal natural resonance; that is easier to manufacture using less components; and is highly efficient, that is able to produce a high SPL at the small dimensions.

[0017] It may therefore be seen as an object of embodiments of the present invention to provide for a receiver that combines one or more, preferably all, of these advantages. The present invention provides such a receiver.

[0018] Accordingly, the present invention provides according to a first aspect, a receiver comprising

[0019] - a receiver housing having a sound outlet in acoustic communication with a front volume within the receiver housing;

[0020] - a diaphragm arranged within the receiver housing, said diaphragm separating the front volume and a rear volume within the receiver housing, wherein at least part of the diaphragm is configured to vibrate in response to a drive signal applied to a voice coil positioned in the rear volume; and - a magnetic motor configured to generate a static magnetic field in a space within which at least part of the voice coil is positioned; characterized in that the receiver is for use in an ear canal of a person; and that a residual acoustic rear volume in the rear volume is at most 15 mm3; a combined acoustic mass of the diaphragm and voice coil is at most 130000 kg / m4; and the product of the combined acoustic mass of the diaphragm and voice coil times the residual acoustic rear volume (expressed in m3) is in the range of from 3.0E-4 to 9.5E-4 (i.e. 3.0 * 10’4to 9.5 * 10’4) kg / m.

[0021] The receiver is for use in an ear canal of a person and accordingly is configured such that it fits the ear canal of a person. The ear canal of a person is generally oval shaped. Typically, the receiver housing is elongated in shape and in cross-section, perpendicular to the elongated shape of the receiver housing, the dimensions will not be more than 3.2 x 2.7 mm, preferably not more than 3.1 x 2.6 mm.

[0022] The residual acoustic rear volume is the volume of air in a rear volume, that is the rear volume between the receiver housing and the diaphragm, excluding the volume of any solid components in that rear volume, such as voice coil and magnetic motor.

[0023] The acoustic mass is determined as follows:

[0024] Measure the residual acoustic rear volume V_rear in m3;

[0025] Measure the first main acoustic resonance f0of the receiver in Hz; and

[0026] Calculate the total acoustic mass Ma_tot by solving the following equation:

[0027] In which rho_air = 1.225 kg / m3 and c_air = 340 m / s.

[0028] As the desired output of the receiver is acoustical, i.e. in the acoustical domain, and the construction of the diaphragm and voice coil is in the mechanical domain, the mass of the diaphragm and voice coil (expressed in kg) may be converted to an equivalent acoustical mass. It belongs to the skill of those skilled in the art to convert (mechanical) mass of the diaphragm of voice coil and diaphragm into an equivalent acoustical mass. In essence, Matot = [ m(diaphragm) + invoice coii)] / A2, in which m is the mass of diaphragm, respectively voice coil, and A is the area of the diaphragm. In the configuration where a hinged diaphragm is used, not all of the diaphragm contributes equally to the movement of air and the effective contribution of each part of the diaphragm is calculated by means of integration as follows:

[0029] In which Aeff is the effective area and the force point (FP) amplitude is the amplitude of the diaphragm at the centre of the voice coil; and

[0030] In which mdlaphragm effis the effective mass of the diaphragm and FP is the force point, i.e. the centre of the voice coil. The effective mass of the voice coil, mvolce coil efflmay be determined in a similar way.

[0031] The residual acoustic air volume equivalent in the acoustic domain is the acoustic compliance.

[0032] Acoustic compliance, Ca, may be determined using the following equation:

[0033] In which rho_air = 1.225 kg / m3; c_air = 340 m / s and V_rear is the residual acoustic rear volume in m3.

[0034] Preferably, in embodiments of the invention according to the first, second and third aspect, the acoustic compliance is at most 1.04E-13 m5 / N. Furthermore, preferably, in embodiments of the invention according to the first, second and third aspect, the product of the combined acoustic mass of the diaphragm and voice coil times the acoustic compliance is in the range of from 2.1E-9 to 6.3E-9 s2.

[0035] Preferably, the residual acoustic rear volume in the rear volume is at most 14 mm3, more preferably at most 12 mm3, even more preferably at most 11 mm3. Preferably, the residual acoustic rear volume is at least 7 mm3, more preferably at least 8 mm3.

[0036] Preferably, the combined acoustic mass of the diaphragm and voice coil is at most 90000 kg / m4, more preferably at most 60000 kg / m4. Preferably, the combined acoustic mass of the diaphragm and voice coil is at least 25000 kg / m4, more preferably at least 30000 kg / m4.

[0037] Preferably, the product of the combined acoustic mass of the diaphragm and voice coil times the residual acoustic rear volume (expressed in m3) is in the range of from 3.9E-4 to 8.9E-4 kg / m, more preferably in the range of from 3.9E-4 to 6.4E-4 kg / m. Preferably, according to this first aspect, at least the part of the housing designed for direct contact with an ear canal, is at least partly made of a biocompatible material. The part of the receiver housing that may be in direct contact with an ear canal may (substantially) completely be covered by an outer layer of a biocompatible material or may be formed from a biocompatible material.

[0038] According to a second aspect, the present invention provides a receiver for use in an ear canal of a person comprising

[0039] - a receiver housing having a sound outlet in acoustic communication with a front volume within the receiver housing;

[0040] - a diaphragm arranged within the receiver housing, said diaphragm separating the front volume and a rear volume within the receiver housing, wherein at least part of the diaphragm is configured to vibrate in response to a drive signal applied to a voice coil positioned in the rear volume; and

[0041] - a magnetic motor configured to generate a static magnetic field in a space within which at least part of the voice coil is positioned; wherein at least the part of the housing that is designed for direct contact with an ear canal, is at least partly made of a biocompatible material.

[0042] Preferably, a residual acoustic rear volume in the rear volume is at most 15 mm3; the combined acoustic mass of the diaphragm and voice coil is at most 130000 kg / m4; and the product of (combined acoustic mass of diaphragm and voice coil) times the residual acoustic rear volume is in the range of from 3.0E-4 to 9.5E-4 kg / m.

[0043] More preferably, or even more preferably, for this embodiment, the residual acoustic rear volume; and / or the combined acoustic mass of the diaphragm and voice coil; and / or the product of (combined acoustic mass of diaphragm and voice coil) times the residual acoustic rear volume, are selected from preferred and more preferred limits as defined hereinabove with respect to the first aspect of the invention.

[0044] Biocompatible materials are known in the art and are for example described in United States patent specification No. 7,680,292, incorporated herein by reference. Examples include polyolefins such as polypropylene or polyamides, such as glass-reinforced polyamides.

[0045] According to a third aspect, the present invention provides a receiver for use in an ear canal of a person comprising

[0046] - a receiver housing having a sound outlet in acoustic communication with a front volume within the receiver housing;

[0047] - a diaphragm arranged within the receiver housing, said diaphragm separating the front volume and a rear volume within the receiver housing, wherein at least part of the diaphragm is configured to vibrate in response to a drive signal applied to a voice coil positioned in the rear volume; and

[0048] - a magnetic motor configured to generate a static magnetic field in a space within which at least part of the voice coil is positioned; wherein an air venting opening in the housing is configured to vent the rear volume to an enclosed vent volume.

[0049] Preferably, according to this third aspect, a residual acoustic rear volume in the rear volume is at most 15 mm3; a combined acoustic mass of the diaphragm and voice coil is at most 130000 kg / m4; and the product of the combined acoustic mass of the diaphragm and voice coil times the residual acoustic rear volume is in the range of from 3.0E-4 to 9.5E-4 kg / m.

[0050] More preferably, or even more preferably, for this embodiment, the residual acoustic rear volume; and / or the combined acoustic mass of the diaphragm and voice coil; and / or the product of the combined acoustic mass of the diaphragm and voice coil times the residual acoustic rear volume, are selected from preferred and more preferred limits as defined hereinabove with respect to the first aspect of the invention.

[0051] Preferably, according to this third aspect, at least the part of the housing that is designed for direct contact with an ear canal, is at least partly made of a biocompatible material.

[0052] It will be appreciated that the receiver according to the first and second aspect, preferably, comprises an air venting opening in the housing, such as the rear receiver housing part, which is configured to vent the rear volume, more preferably to an enclosed vent volume.

[0053] Unless specifically set out below, other preferred embodiments apply to both the first, second and third aspects of the invention.

[0054] Hearing aid devices using a receiver in canal are currently typically designed for balanced armature drivers. One consequence of this is that any amplifiers used in such hearing aid devices need to have a high impedance of at least 40 Ohm. It would be desirable to be able to use the receiver of the present invention in existing hearing aid designs, without having to change or re-design other components used in hearing aid devices, such as amplifiers.

[0055] Preferably, the voice coil comprises at least 24 windings, more preferably 60 to 120 windings, of insulated electrically conductive wire, where the diameter of the electrically conductive wire is at most 22 pm. More preferably, the diameter of the electrically conductive wire is in the range of from 12 to 18 pm. If the diameter of the electrically conductive wire is more than 22 pm, a high impedance is more difficult to achieve, and the combined required acoustic mass of voice coil and diaphragm becomes more difficult to achieve as well. If the diameter of the electrically conductive wire is less than 12 pm, handling of the electrically conductive wire becomes more difficult and the risk that the wire breaks during manufacture increases, resulting in loss of yield. Preferably the voice coil is configured such that the impedance is at least 16 Ohm, preferably at least 30 Ohm, more preferably at least 40 Ohm.

[0056] The housing is typically elongated, such as oblong, and the diaphragm is typically elongated, such as oblong, as well. Preferably, the diaphragm comprises, more preferably is, a hinged diaphragm arranged within the elongated, oblong, housing. The hinged diaphragm comprises a hinged portion and a moveable portion, wherein at least the moveable portion of the diaphragm is configured to vibrate in response to the drive signal. In this embodiment, the voice coil is secured to the moveable portion of the diaphragm, preferably at a distance from the hinged portion.

[0057] In the present context the term "hinged diaphragm" should be understood as a diaphragm that is hinged to for example a frame structure. The hinging of the diaphragm to for example a frame structure may be arranged in various ways, such as by applying one or more integrated hinges, applying one or more distinct and separate hinges and / or one or more film-based hinges.

[0058] Preferably, the hinged diaphragm is substantially rectangular and the diaphragm is hinged on one side of the substantially rectangular diaphragm, more preferably a short end of the substantially rectangular diaphragm. Preferably the voice coil is positioned such that at least part of the outer perimeter of the voice coil is positioned substantially at the end opposite the end where the diaphragm is hinged.

[0059] According to a preferred aspect of the receiver of the present invention, the receiver comprises an oblong housing; a sound output port arranged in the oblong housing; a hinged diaphragm arranged within the oblong housing and separating a front volume and a rear volume within the oblong housing, wherein the hinged diaphragm comprises a hinged portion and a moveable portion, and wherein at least the moveable portion of the hinged diaphragm is adapted to vibrate in response to a drive signal applied to a voice coil secured to the moveable portion of the diaphragm; and a magnetic motor arranged within the oblong housing, wherein the magnetic motor is adapted to generate a static magnetic field in an air gap within which at least part of voice coil is positioned.

[0060] Hinging of the diaphragm is advantageous in that the hinge avoids or at least counteracts rocking modes, i.e. undesired tilting motions of the diaphragm which is a widely known phenomena in conventional (non-hinged) moving coil loudspeaker designs. In conventional designs of miniature receivers, the small diaphragm sizes are, in general, associated with relatively large driving amplitudes, which in combination frequently triggers problems with rocking modes. Since the amplitude of the tilting motion scales with voice coil excursion, and since the air gaps for the voice coil are narrow for efficiency reasons (typically in the range of from 0.15 to 0.35 mm), the voice coil will at a certain level hit the magnet causing excessive impulsive distortion due to rubbing. The rubbing of the voice coil along the air gap (magnet) wall also quickly breaks the coatings of the voice coil wire and can thus cause the receiver to fail. Thus, the risk of rocking modes imposes strong limitations of usable output and lifetime of conventional miniature receivers, let alone receivers for use in an ear canal of a person as in the present invention.

[0061] According to a preferred embodiment, the hinged diaphragm is hinged to a frame structure, and wherein one or more openings exist between the hinged diaphragm and the frame structure.

[0062] The hinged portion of the hinged diaphragm is preferably hinged to a frame structure via one or more discrete and separate hinges and / or via one or more integrated hinges.

[0063] In the present context the term "integrated hinges" is to be understood as hinges that are integrated with the frame structure, the hinged diaphragm or both. The hinged diaphragm and the frame structure may form an integrated structure of the same material, such as metal, preferably aluminum.

[0064] The one or more openings between the hinged diaphragm and the frame structure are provided so that at least part of the hinged diaphragm is allowed to vibrate, and thus generate audible sound waves, when a drive signal is applied to the voice coil. The one or more openings between the hinged diaphragm and the frame structure may at least partly be sealed or filled with a flexible sealing member, such as a (corrugated) polymer film or a viscoelastic substance such as a viscoelastic gel. Sealing the one or more openings is advantageous in order to acoustically separate the front and rear volumes of the receiver.

[0065] At least part of the hinged diaphragm may comprise an embossed part for increasing the stiffness of the diaphragm. The embossed part may be implemented as an indentation or recess that extends in the opposite direction of the voice coil secured to the moveable portion of the diaphragm. Another way of increasing the stiffness of the hinged diaphragm may be to secure a stacked layer or stacked pre-formed layer to the diaphragm. The embossed part of at least part of the hinged diaphragm may provide an air venting path for air inside the magnetic motor as discussed in relation to some of the drawings.

[0066] Preferably, the hinged diaphragm has an elongated, oblong, preferably substantially rectangular, shape, wherein the length of the hinged diaphragm in the elongated, oblong direction is at least twice the width of the diaphragm. Thus, the length of the hinged diaphragm in the elongated, oblong direction may be three times, four times, five times or even ten times the width of the diaphragm. The elongated, oblong shape of the hinged diaphragm is advantageous in that it maximizes the area of the hinged diaphragm within the elongated, oblong housing of the receiver. Moreover, the maximized area of the hinged diaphragm enhances the performance of the receiver.

[0067] The voice coil typically may be in the form of a cylinder or a cuboid with the top side and bottom side of the cylinder or cuboid being open. The top side of the voice coil is the part of the voice coil nearest to the moveable portion of the diaphragm. The bottom side of the voice coil is the part opposite the top side and furthest from the moveable portion of the diaphragm. The top-side (and bottom side) view of the cylindrical voice coil may be a plane that is an ellipse shape or a circle. The top-side (and bottom side) view of the cuboid voice coil may be a plane that is a substantially square or rectangular shape. If desired, the edges of the substantially square or rectangular shape may be rounded. In this specification, the cuboid shaped voice coil is referred to as a substantially square (also referred to in this specification as quadratric) or rectangular voice coil. The cylinder-shaped voice coil may be referred to as an ellipsoid (oval-shaped) or circle-shaped voice coil. Preferably, the voice coil is rectangular.

[0068] The voice coil is typically secured to the diaphragm, in particular to the movable portion of a hinged diaphragm comprising a hinged portion and a moveable portion. The voice coil preferably comprises at least 24 windings of insulated electrically conductive wire, preferably 60 to 120 windings of insulated electrically conductive wire, where the diameter of the electrically conductive wire is at most 22 pm. Preferably, the diameter of the electrically conductive wire is in the range of from 12 to 18 pm. The relevant diameter is the diameter of the electrically conductive wire itself, without insulating layer. In principle, any electrically conductive wire, such as copper, may be used. Preferably, an electrically conductive wire is used with a ratio of conductivity to mass density higher than copper. Preferably, the mass density of the electrically conductive wire is less than 3 g / cm3. More preferably, the electrically conductive wire is essentially aluminum. If desired, the aluminum wire may be coated with copper or silver, for example to improve solderability. The voice coil extends in a direction essentially perpendicular to the diaphragm. Thus, windings of the voice coil extend essentially perpendicular to the diaphragm and the thickness of a side of a voice coil secured to the diaphragm is therefore essentially the diameter of one electrically conductive wire, plus any insulating material. The voice coil is at least in part positioned in an air gap of the magnetic motor. The hinged diaphragm to which the voice coil is preferably secured, reduces rocking modes, which in turn allows to dimension the width of the air gap to be in the range of from 0.15 to 0.35 mm, which is primarily advantageous to increase magnetic flux density in the air gap, increasing the magnetic motor force. A small air gap is also advantageous for reducing the residual acoustic rear volume to at most 15 mm3.

[0069] The length of the hinged diaphragm in the oblong direction is at least twice the diameter or the width of the voice coil secured to the moveable portion of the diaphragm. Thus, the length of the hinged diaphragm in the oblong direction may be three times, four times, five times or even ten times the diameter or the width of the voice coil. The width of the voice coil may correspond to the side length of a square voice coil or the shortest side length of a rectangular voice coil. The diameter of the voice coil may correspond to the shortest diameter of the ellipsoid (oval shaped) voice coil or the diameter of the circle-shaped voice coil.

[0070] An air venting opening may be arranged in the oblong housing of the miniature receiver. The air venting opening may be displaced or shifted relative to the magnetic motor. The air venting opening may be oppositely arranged relative to the sound outlet port, or it may be arranged as side opening in the oblong housing. In any case, the air venting opening may be adapted to vent the rear volume of the miniature receiver.

[0071] The venting opening may comprise an acoustical filter element forming an acoustical filter having an acoustical resistance, such as an acoustical low-pass filter having an acoustical resistance in the range of 1 - 20 GPa.s / m3.

[0072] The cut-off frequency of such an acoustical low-pass filter may be in range of 100-1000 Hz, such as 200-800 Hz, and the acoustical low-pass filter may be implemented as a mesh comprising one or more small holes (drilled or laser-cut), wire mesh, grid, fabric, non-woven fabric or another arrangement with similar acoustical properties. The purpose of the acoustical filter is to allow the rear volume of the miniature receiver to be vented for signal frequencies below the filter cut-off, and to inhibit venting for frequencies above the cut-off. The advantage of such a filter is that the low frequency output is increased, while the resonance frequencies are not affected by the additional volume. The main property of the acoustical filter is the acoustical resistance. The acoustical resistance of the acoustical filter that is required to achieve a certain cut-off frequency is dependent of the acoustical compliance of the rear volume. For example, in order to have a cut-off frequency of 500 Hz with a rear volume between 10 and 15 mm3, the acoustical resistance of the acoustical filter may be between 1.3 and 10 GPa.s / m3.

[0073] The oblong housing of the miniature receiver may be defined by first and second oblong housing parts in combination. The sound outlet port may be arranged in the first oblong housing part, and the air venting opening may be arranged in the second oblong housing part. The frame structure around the hinged diaphragm may, according to one embodiment, form at least part of a sealing between the first and second oblong housing parts, and electrical terminals may be provided on an exterior surface of the oblong housing.

[0074] The magnetic motor may be distinct and separate motor. The magnetic motor may thus comprise a stacked arrangement of a permanent magnet and an inner yoke, wherein the permanent magnet and the inner yoke are at least partly arranged within an outer yoke so that an air gap is provided between the inner yoke and the outer yoke. The air gap is adapted to receive at least part of the voice coil, i.e. the voice coil is at least partly arranged within the air gap.

[0075] The outer yoke may comprise one or more ventilation openings adapted to ventilate an air volume inside the magnetic motor. Proper ventilation of the magnetic motor is advantageous as it may lead to an increased performance of the miniature receiver.

[0076] The magnetic motor may alternatively form part of the housing of the receiver in order to increase the power of the motor. In this implementation the magnetic motor may comprise a stacked arrangement of a permanent magnet and an inner yoke, wherein the permanent magnet and the inner yoke are at least partly arranged within an outer yoke formed by a portion of the oblong housing. Thus, in this implementation the housing of the receiver may form at least part of an outer yoke of the magnetic motor. In this embodiment, preferably the part of the housing of the receiver that forms at least part of an outer yoke of the magnetic motor is covered by a biocompatible outer layer.

[0077] In case the housing of the receiver forms at least part of an outer yoke of the magnetic motor, the voice coil is preferably elongated, such as rectangular or oval shaped where the longest elongation such as the longest side length of a rectangular voice coil or the longest diameter of an oval shaped voice coil is arranged substantially parallel to the length of the hinged diaphragm in the oblong direction. In this embodiment, the length of the hinged diaphragm in the oblong direction is at least 1.1 times, preferably at least 1.3 times, 1.5 times or 1.7 times, such as 2.0 times the longest elongation, such as the longest diameter or the longest side length, of the voice coil secured to the moveable portion of the diaphragm. The length of the hinged diaphragm in the oblong direction may be up to 4 times, such as up to 3 times, 2.5 times, or 2 times the longest elongation, such as the longest diameter or the longest side length, of the voice coil.

[0078] The elongated, oblong, housing of the receiver may typically have an outer width in the range of 3-5.5 mm, an outer height within the range of 1.5-5 mm, and an outer length, excluding nozzle and cable strain relief, in the range of 6-9 mm. Preferably, the housing is shaped such that the fit rate for adults of the receiver for use in the ear canal is at least 90%. A fit rate may be improved by a receiver housing that is made of a biocompatible material, and a separate biocompatible cover for the receiver housing can be avoided; and by shaping the housing such that the fit rate in the outer ear canal is improved. Thus, according to one embodiment, the housing comprising a front receiver housing part comprising a front volume of the receiver and a rear receiver housing part comprising a rear volume of the receiver (or a part thereof), which housing, when viewed in longitudinal cross-section through essentially the entire receiver housing with the front receiver housing part on top and the rear receiver housing part at the bottom of the cross-section, may have a curved or bended shape.

[0079] Preferably, the receiver is configured to a resonance frequency peak, first main acoustic resonance peak of the receiver (f0), in the range of from 2.0 to 3.5 kHz, more preferably of from 2.5 to 3 kHz.

[0080] According to another aspect, the present invention relates to a voice coil for use in a receiver as described herein, wherein the voice coil comprises at least 24 windings of insulated electrically conductive wire, preferably 60 to 120 windings of insulated electrically conductive wire, where the diameter of the electrically conductive wire is at most 22 pm. Preferably, the diameter of the electrically conductive wire is in the range of from 12 to 18 pm. Other preferred embodiments of the voice coil have been described hereinabove.

[0081] Preferably, the voice coil is made of self-bonding coil wire, that is film isolated wire which is coated with an additional bonding adhesive.

[0082] According to another aspect, the present invention relates to a receiver housing adapted for a receiver as described herein, wherein the receiver housing has an oblong shape comprising a bend, wherein the angle a of the bend is in the range of from 5 to 40°, preferably 10 to 30°. More preferably the angle a of the bend is in the range from 12 to 28°, even more preferably 15 to 25°, such as 17 to 23°. The bend in the oblong shape is typically in the main body of the receiver housing. If desired, the orientation of the nozzle may also be bended relative to the receiver housing and / or the orientation of the cable attachment portion may also be bended relative to the receiver housing. Typically, it will be preferred that the bend in the main body of the receiver housing and a second bend, if any, between the nozzle and the receiver housing and a third bend, if any, between the cable attachment portion and the receiver housing are substantially in the same direction such that the overall shape of the receiver housing according to the invention may be described as 'banana'-shaped. The main body of the receiver housing is substantially rigid. Typically, at least the main body and the nozzle are substantially rigid and preferably the cable attachment portion is rigid as well. Thus, the angle of the bend in the main body of the receiver housing and a second bend, if any, between the nozzle and the receiver housing and a third bend, if any, between the cable attachment portion and the receiver housing are essentially fixed. WO2022 / 019752 describes a receiver valve combination, which receiver and valve are connected by a flexible interlink to allow better fit into the ear. In the receiver housing according to the present invention, at least no flexible interlink exists in the main body of the receiver housing.

[0083] According to another aspect, the present invention relates to a receiver housing adapted for a receiver as described herein, wherein the receiver housing has an oblong shape comprising a bend defining a convex and concave side of the receiver housing, wherein the angle of bend e on the convex side of the receiver housing is at most 175°, preferably at most 170° and the angle of bend on the concave side of the receiver housing is at most 175°, preferably at most 170°. More preferably the angle of bend e on the convex side of the receiver housing is at most 165°, even more preferably at most 160°. Typically, the angle of bend e is not less than 140°, preferably 150°, more preferably, not less than 155°. More preferably, the angle of bend on the concave side of the receiver housing is at most 165°, even more preferably at most 160°. Typically, the angle of bend is not less than 140°, preferably 150°, more preferably not less than 155°. Preferably, the difference between angle and angle e is not more than 30°, such as 0 to 20°, preferably 0 to 10°.

[0084] Preferably, the oblong shape between the bend defining the convex and concave side of the receiver housing and the nozzle may be tapered towards the nozzle.

[0085] According to another aspect, the present invention relates to a receiver-in-canal assembly comprising a receiver as described herein; a connector; and an electrically conductive wire for connecting the receiver with the connector, which connector is configured to connect with a second connector in a hearing device housing external to the ear canal. According to one embodiment, the receiver in canal assembly further comprises a microphone, in particular a MEMS microphone, in the receiver housing or downstream from the receiver housing. The MEMS microphone may suitably be positioned in the rear volume of the receiver housing, downstream from the magnetic motor.

[0086] According to another aspect, the present invention relates to a receiver / microphone assembly comprising a receiver as described herein, wherein the housing further comprises a microphone, in particular a MEMS microphone. Suitably, the MEMS microphone may be positioned in the rear volume of the receiver housing, downstream from the magnetic motor.

[0087] According to another aspect, the present invention relates to a hearing aid device comprising a receiver in canal assembly as described herein and a hearing device housing comprising a second connector configured for connecting with the connector of the receiver in canal assembly; a power source such as a battery; one or more microphones configured to receive sound from sources external to the ear canal of a person and generate first output signal(s); and a processor configured to provide the drive signal for the voice coil in the receiver in canal assembly from the first output signal(s). According to one embodiment, in determining the drive signal, the processor may be configured to operate an Active Noise Cancelling algorithm.

[0088] Preferably, the processor is further configured to receive a second output signal from the microphone in the receiver in canal assembly, and provide the drive signal for the voice coil in the receiver in canal assembly from the first output signal(s) and the second output signal. According to one embodiment, in determining the drive signal, the processor may be configured to operate an Active Noise Cancelling (ANC) algorithm and / or an Active Occlusion Reduction (AOR) algorithm. An AOR algorithm and system may be similar to an ANC algorithm and system but in case of AOR the noise targeted for cancellation comprises occlusion related noise sources.

[0089] In general, the various aspects of the present invention may be combined and coupled in any way possible within the scope of the invention. These and other aspects, features and / or advantages of the present invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0090] BRIEF DESCRIPTION OF THE DRAWINGS

[0091] In the following, example embodiments will be described with reference to the drawings, wherein:

[0092] Figure 1 illustrates a receiver according to the invention in exploded view. Figure 2 illustrates a top view of a hinged diaphragm of a receiver according to the present invention.

[0093] Figure 3 illustrates top views of other hinged diaphragms, where Fig. 3a shows a film-based hinge, and Fig. 3b shows two distinct and separate glue hinges.

[0094] Figure 4 illustrates cross-sectional views of different ways of venting of the volume enclosed by the voice coil in a housing in which the residual acoustic rear volume of the rear volume is minimized. In Fig. 4a the venting is provided via the embossment of the diaphragm, and in Fig. 4b the venting is provided via venting holes in the outer yoke.

[0095] Figure 5 illustrates in exploded view a rear receiver housing part in which the residual acoustic rear volume is minimized and a diaphragm voice coil assembly to be mounted in the rear housing part.

[0096] Figure 6(a) illustrates a receiver housing, in longitudinal cross-section, with improved fit rate within an ear canal, wherein the receiver housing comprises a first portion at an angle relative to a second portion of the receiver housing. Figure 6(b) shows the same receiver housing with the diaphragm, voice coil and magnetic motor positioned therein.

[0097] Figure 7 illustrates a rear receiver housing part with a vent volume.

[0098] Figure 8 illustrates a receiver housing according to the present invention.

[0099] DETAILED DESCRIPTION OF THE INVENTION

[0100] Figure 1 illustrates a receiver according to the invention in exploded view. The receiver 100 comprises housing 101, 120. The housing consists of two parts. A first housing part 101 is configured to receive a frame structure 102 and diaphragm 103 containing an embossed part and form a space (not shown) between the frame structure / diaphragm 102,103 and the first housing part 101, the front volume. Diaphragm 103 is hinged in frame structure 102 via hinges 105, 105'. The openings 104 between the hinged diaphragm 103 and the frame structure 102 are sealed with a corrugated polymer film. A second housing part 120 is configured to receive (i) a magnetic motor comprising an outer yoke 116, permanent magnet 117 and inner yoke 115; and (ii) the frame structure 102 and diaphragm 103, to which a voice coil 110 is to be secured. The voice coil 110 is positioned in an air gap formed by a space between outer yoke 116 and permanent magnet 117 / inner yoke 115. Thus, the magnetic motor 116, 117, 115 generates a static magnetic field in a space within which at least part of the voice coil is positioned. The residual acoustic rear volume in the rear volume is at most 15 mm3. Preferably, at least the outer part of housing 101, 120 facing the ear canal is made of a biocompatible material. Sound outlet 150 is formed by nozzle 140, 140'. It will be appreciated that the nozzle may be formed in one, first or second, housing part, but for ease of manufacture it is preferred that nozzle part 140 is an integral part of first housing part 101 and that nozzle part 140' is an integral part of second housing part 120.

[0101] Turning now to Figure 2, a top view of an integrated assembly 200 comprising the hinged diaphragm 201 and the frame structure 202 is depicted. The hinged diaphragm 201 and the frame structure 202 preferably form an integrated structure of the same material, such as metal including aluminum. The hinged diaphragm 201 is hinged to the frame structure 202 via hinges 205, 205' that are integrated hinges. The openings 204, 206 between the hinged diaphragm 201 and the frame structure 202 are sealed with a corrugated polymer film having one or more venting opening 207 arranged between the hinges 205, 205'. These one or more venting openings are provided in order to equalize the barometric pressure between the front and the rear volume. At least part of the hinged diaphragm 201 comprises an embossed part 203 for increasing the stiffness of the diaphragm and / or for providing an air venting path as will be discussed in further detail below.

[0102] In an alternative arrangement, the hinged diaphragm 301, 306 is hinged to the frame structure 302, 307 via discrete and separate glue hinges 304, 310, 310', cf. Figs. 3a-b. With reference to Fig. 3a a thin film 305 in the narrow gap between the hinged diaphragm 301 and the frame structure 302 act as a hinge 304. The opening 303 between the hinged diaphragm 301 and the frame structure 302 is sealed with a corrugated polymer film. In Fig. 3b discrete and separate hinges 310, 310' are secured to the hinged diaphragm 306 and the frame structure 307. The opening 308 between the hinged diaphragm 306 and the frame structure 307 is sealed with a corrugated polymer film, and the opening 309 between the hinges 310, 310' is sealed with a film that may comprise venting / barometric openings (not shown).

[0103] Figs. 4a-b show embodiments of the present invention where the receiver 400, cf. Fig. 4a, comprises hinged diaphragm 405 with an embossed part 408, and wherein Fig. 4b shows a receiver 420 with a flat hinged diaphragm 418.

[0104] Returning to Fig. 4a, the receiver 400 comprises a housing comprising a front housing part 401 and a rear housing part 401'. The front housing part 401 comprises a sound outlet port 404 and the rear housing part 401' comprises a venting opening 415. The venting opening 415 may have an acoustical filter (not shown), such as a low-pass filter, arranged therein. The low-pass filter may typically have an acoustical resistance in the range of 1 - 20 GPa.s / m3. Within the housing 401, 401' a front volume 402 and a rear volume 403 are provided. Rear housing part 401' is shaped such that the residual acoustic rear volume in the rear volume 403 is minimized to e.g. 10 mm3. Thus, in this embodiment, the rear housing part 401' is essentially a shallow cup 440 at a minimal distance from hinged diaphragm 405, which rear housing part 401' comprises a protrusion 430 to accommodate the outer yoke 411.

[0105] An electrical terminal 417 is provided on the exterior of the receiver 400, more particularly on the exterior of the housing 401, 401'. The electrical terminal 417 is electrically connected (not shown) to the voice coil 412 so that a drive signal can be provided thereto via the electrical terminal 417.

[0106] The volumes 402, 403 are separated by the hinged diaphragm 405. The hinged diaphragm 405 comprises a hinged portion and a moveable portion, wherein at least the moveable portion of the hinged diaphragm 405 is adapted to vibrate, and thus generate sound waves, in response to a drive signal applied to a voice coil 412 secured to the moveable portion of the hinged diaphragm 405. As seen in Fig. 4a at least part of the hinged diaphragm 405 comprises an embossed part 408 for increasing the stiffness of the diaphragm and / or for providing an air venting path so that the air volume 413 inside the magnetic motor can be vented. The magnetic motor comprises a permanent magnet 410 sandwiched between a inner yoke 409 and an outer yoke 411. The inner yoke 409 and the outer yoke 411 form an air gap within which at least part of the voice coil 412 is positioned. The hinged diaphragm 405 is hinged via one or more hinges 406 to a frame structure 414. The hinged diaphragm 405 and the frame structure 414 preferably form an integrated structure of the same material, such as metal including aluminum. The hinged diaphragm 405 and the frame structure 414 are separated by one or more openings which are at least partly filled with a flexible sealing member 407, such as a corrugated polymer film or a viscoelastic gel. With the flexible sealing member 407 applied in the one or more openings between the hinged diaphragm 405 and the frame structure 414, the front and rear volumes 402, 403 are acoustically sealed from each other.

[0107] Referring now to Fig. 4b the flat hinged diaphragm 418 does not provide an air venting path for venting the air volume 421. In this embodiment, one or more venting openings 419, 419' are provided in the outer yoke 422. Otherwise, the receiver 400 (Fig. 4a) is identical to the receiver 420 (Fig. 4b).

[0108] Figure 5 illustrates in exploded view a rear receiver housing part 520 in which the residual acoustic rear volume is minimized to for example 10 mm3 and a diaphragm voice coil assembly 502, 503, 510 to be mounted in the rear receiver housing part 520. In the rear receiver housing part 520 a magnetic motor is positioned, comprising an inner yoke 515 to which a permanent magnet is secured (not shown) and an outer yoke 516. The outer yoke 516 is made of a soft magnetizable material such as mu-metal. The space between the inner yoke 515 and permanent magnet assembly and the outer yoke 516 defines an air gap into which the voice coil 510 is to be positioned. In the air gap a permanent magnetic flux is formed between the permanent magnet and outer yoke 516. The voice coil 510 is positioned in the air gap and, in operation, a drive signal applied to the voice coil 510 causes the diaphragm 503 to vibrate. The voice coil 510 is secured to the diaphragm 503, which diaphragm is hinged along integrated hinges 505, 505' and forms an integrated structure with the frame structure 502 and is made of the same material, such as metal including aluminum. The openings 504 between the hinged diaphragm 503 and the frame structure 502 are sealed with a viscoelastic substance such as a viscoelastic gel or a (corrugated) polymer film. The diaphragm 503 may comprise an embossed part (not shown) for increasing the stiffness of the diaphragm and / or for providing an air venting path. Further, one or more venting openings (not shown) may be arranged between the hinges 505, 505' or at another position such as in the sealed openings 504. These one or more venting openings may be provided in order to equalize the barometric pressure between the front and the rear volume. Preferably, at least the outer part of rear housing part 520, facing the ear canal, is made of a biocompatible material. To reduce the residual acoustic rear volume in the rear volume to at most 15 mm3, for example 10 mm3, the part of the receiver housing indicated with 560 is filled with solid material, for example the same biocompatible material used for the receiver housing or may be used for another purpose, not as residual acoustic rear volume. For example, in one embodiment, a microphone, such as a MEMS microphone, may be positioned in the part of the receiver housing indicated with 560. This may assist in real ear measurement (REM) and as input for Active Occlusion Reduction systems.

[0109] Figures 6 (a) and (b) illustrate a receiver housing 605 in longitudinal cross-section with improved fit rate within an ear canal, wherein the receiver housing 605 comprises a first section 601 accommodating the nozzle 640, wherein the first section is at an angle a relative to a second section 602 of the receiver housing 605 accommodating the cable attachment portion 610. With reference to figure 6(a), dashed line 612 represents an imaginary line drawn from immediately downstream from the cable attachment portion 610 at a location equidistant from the top and bottom of the receiver housing 605. Dashed line 614 represents an imaginary line drawn from immediately upstream of the nozzle 640 to dashed line 612 at a location equidistant from the top and bottom edge of the receiver housing 605. As shown in Figure 6(a), the nozzle 640 may be tilted at an angle relative to dashed line 614. As shown schematically in figure 6(b), in the receiver housing 605 the diaphragm 660 and magnetic motor 650, comprised of permanent magnet, inner and outer yoke, are positioned with a rear volume 620 and a front volume 630. A voice coil (not shown) is secured to the rear volume side of the diaphragm 660, and the magnetic motor 650 is configured to generate a static magnetic field in an air gap between the permanent magnet and outer yoke, within which air gap at least part of the voice coil is positioned. Preferably, at least the outer part of housing 605 facing the ear canal is made of a biocompatible material.

[0110] Figure 7 illustrates in longitudinal cross-section, a rear receiver housing part 720 with a vent volume 740. The rear receiver housing part 720 encompasses a space 730 configured to receive the outer yoke of a magnetic motor. Ridge 710 is configured to accommodate a frame structure for a hinged diaphragm (not shown). It is an embodiment of the present invention that the residual acoustic rear volume in the rear volume is at most 15 mm3. To reduce the residual acoustic rear volume in the rear volume to at most 15 mm3, for example 10 mm3, the part of the receiver housing indicated with 560 in figure 5 is filled with solid material, for example the same biocompatible material used for the receiver housing, or the external receiver housing shape is adapted, as shown in figure 4. Preferably, as shown in figure 7, the part of the receiver housing indicated with 560 in figure 5 is not filled with solid material, but used as a closed venting volume 740 for the rear volume. Preferably the closed venting volume is as large as possible, for example 10-15 mm3. A venting opening 745, typically 0.6-0.9 mm in diameter, is provided in acoustic communication with the residual acoustic rear volume. The venting opening 745 comprises an acoustical filter 741, such as a low-pass filter, preferably having an acoustical resistance in the range of 1-20 GPa.s / m3. The acoustical filter 741 may be implemented in various ways, such as an acoustical mesh. The venting volume 740 provides additional efficiency, especially at low frequencies such as below 800 Hz. The closed nature of the venting volume 740 ensures that undesirable feedback in the ear canal is reduced or even eliminated. Preferably, at least the outer part of rear receiver housing part 720, facing the ear canal, is made of a biocompatible material.

[0111] Figure 8 illustrates a receiver housing 800 according to the invention comprising a main body of the receiver housing 850 with a generally oblong shape comprising a bend e, At the downstream side of the main body 850, the main body terminates in a nozzle 851 provided with a sound opening, as depicted by line 854. The upstream side of the main body 850, the main body terminates in a cable attachment portion 852, as depicted by line 857. It will be appreciated that, in use, the upstream side of the receiver housing is furthest removed from the ear drum and the downstream side is closest to the ear drum. Typically, the angle of bend e on the convex side of the receiver housing is at most 175°, preferably at most 170°, more preferably at most 165°, even more preferably at most 160°. Typically, the angle of bend e is not less than 140°, preferably not less than 150°, more preferably not less than 155°. Typically, the angle of bend on the concave side of the receiver housing is at most 175°, preferably at most 170°, more preferably at most 165°, even more preferably at most 160°. Typically, the angle of bend is not less than 140°, preferably not less than 150°, more preferably not less than 155°. Preferably, the difference between angle and angle e is not more than 30°.

[0112] Line 853 is a line drawn perpendicular to line 854, defining a central axis at the end of the downstream side of the main body 850. Line 856 is a line drawn perpendicular to line 857, defining a central axis at the end of the upstream side of the main body 850. The intersection of line 853 and 856 defines an angle p. Angle is preferably in the range from 10 to 30°, more preferably from 15 to 25°. Line 855 depicts the central axis of nozzle 851. Angle y is the angle between the central axis 855 and line 853. The angle y may be from 0 to 20°, preferably from 5 to 15°. Line 858 depicts the central axis of cable attachment portion 852. Angle 6 is the angle between the central axis 858 and line 856. The angle 6 may be from 0 to 50° or even 70°. Preferably from 0 to 30°, more preferably from 0 to 15°, such as between 5 and 15°.

[0113] The length of the part of the main body 850 between angle e and line 854 is preferably in the range of from 3 to 6.5 mm, more preferably from 4 to 6 mm. The length of the part of the main body between angle e and line 857 is preferably from 2 to 7 mm, more preferably from 4 to 6 mm.

[0114] Although the present invention has been discussed in the foregoing with reference to exemplary embodiments of the invention, the invention is not restricted to these particular embodiments which can be varied in many ways without departing from the invention. The discussed exemplary embodiments shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary, the embodiments are merely intended to explain the wording of the appended claims, without intent to limit the claims to these exemplary embodiments. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using these exemplary embodiments.

Claims

CLAIMS1. A receiver comprising- a receiver housing having a sound outlet in acoustic communication with a front volume within the receiver housing;- a diaphragm arranged within the receiver housing, said diaphragm separating the front volume and a rear volume within the receiver housing, wherein at least part of the diaphragm is configured to vibrate in response to a drive signal applied to a voice coil positioned in the rear volume; and- a magnetic motor configured to generate a static magnetic field in a space within which at least part of the voice coil is positioned; characterized in that the receiver is for use in an ear canal of a person; and that a residual acoustic rear volume in the rear volume is at most 15 mm3; a combined acoustic mass of the diaphragm and voice coil is at most 130000 kg / m4; and the product of the combined acoustic mass of the diaphragm and voice coil times the residual acoustic rear volume is in the range of from 3.0E-4 to 9.5E-4 kg / m.

2. A receiver according to claim 1, characterized in that at least the part of the receiver housing that is designed for direct contact with an ear canal, is at least partly made of a biocompatible material.

3. A receiver according to any one of the preceding claims, characterized by further comprising an air venting opening in the receiver housing configured to vent the rear volume, preferably to an enclosed vent volume.

4. A receiver according to claim 3, comprising an enclosed vent volume, characterized in that the air venting opening comprises an acoustical filter, preferably having an acoustical resistance in the range of 1-20 GPa.s / m3.

5. A receiver according to any one of the preceding claims, characterized in that the voice coil comprises at least 24 windings of insulated electrically conductive wire, and wherein the diameter of the electrically conductive wire is at most 22 pm.

6. A receiver according to any one of the preceding claims, characterized in that the diaphragm comprises a hinged diaphragm comprising a hinged portion and a moveable portion, and wherein at least the moveable portion of the diaphragm is configured to vibrate in response to the drive signal applied to the voice coil.

7. A receiver according to claim 6, characterized in that the hinged diaphragm is hinged to a frame structure, and wherein one or more openings exist between the hinged diaphragm and the frame structure.

8. A receiver according to claim 7, characterized in that the hinged portion of the hinged diaphragm is hinged to a frame structure via one or more discrete and separate hinges and / or via one or more integrated hinges.

9. A receiver according to claims 7 or 8, characterized in that the hinged diaphragm and the frame structure form an integrated structure of the same material, such as metal including aluminum.

10. A receiver according to any one of the preceding claims 7-9, characterized in that the one or more openings between the hinged diaphragm and the frame structure are at least partly be sealed or filled with a flexible sealing member, such as a corrugated polymer film or a viscoelastic substance.

11. A receiver according to any one of the preceding claims 6-10, characterized in that at least part of the hinged diaphragm comprises an embossed part for increasing the stiffness of the diaphragm.

12. A receiver according to any one of the preceding claims, characterized in that the magnetic motor comprises (i) a stacked arrangement of a permanent magnet and an inner yoke and (ii) an outer yoke, wherein the permanent magnet and the inner yoke are at least partly arranged within the outer yoke so that an air gap is provided between the stacked arrangement of the permanent magnet and inner yoke and the outer yoke within which air gap the voice coil is at least partly arranged.

13. A receiver housing adapted for a receiver according to any one of the preceding claims, wherein the receiver housing has an oblong shape comprising a bend, wherein the angle a of the bend is in the range of from 10 to 30°.

14. A receiver in canal assembly comprising a receiver according to any one of the preceding claims 1-12; a connector; and an electrically conductive wire for connecting the receiver with the connector, which connector is configured to connect with a second connector in a hearing device housing external to the ear canal.

15. A hearing aid device comprising a receiver in canal assembly as claimed in claim 14 and a hearing device housing comprising a second connector configured forconnecting with the connector of the receiver in canal assembly; a power source such as a battery; one or more microphones configured to receive sound from sources external to the ear canal of a person and generate first output signal(s); and a processor configured to provide the drive signal for the voice coil in the receiver in canal assembly from the first output signal(s).

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