WO2015039707A1

WO2015039707A1 - A rechargable hearing device, a hearing device charging system and a method for charging a hearing device

Info

Publication number: WO2015039707A1
Application number: PCT/EP2013/069706
Authority: WO
Inventors: Christian Frei; Daniel Probst
Original assignee: Phonak Ag
Priority date: 2013-09-23
Filing date: 2013-09-23
Publication date: 2015-03-26

Abstract

The present invention provides a hearing device (1) to be worn at least partially within an ear canal, comprising a microphone (25), an electronics unit (26), a receiver (27) and a rechargeable battery (28), which are contained in a housing (2), wherein the hearing device (1) features a coupling means (40) for operationally connecting the battery (28) to a battery charger (5), and the coupling means (40) comprises an inductor and a diode. Furthermore, a hearing device charging system comprising such a hearing device (1) and a battery charger (5) as well as a method for charging such a hearing device (1) are proposed.

Description

A RECHARGABLE HEARING DEVICE , A HEARING DEVICE CHARGING SYSTEM AND A METHOD FOR CHARGING A HEARING DEVICE

TECHNICAL FIELD

The present invention relates to a rechargeable hearing device, in particular a hearing device to be worn at least partially within an ear canal. The present invention further pertains to a hearing device charging system and a method for charging such a hearing device.

BACKGROUND OF THE INVENTION

Portable electronic devices are increasingly being powered by rechargeable batteries. This is also the case for miniature hearing devices adapted to be worn at an ear or at least partially within an ear canal of a user. Such hearing devices include ear phones, communication devices, hearing aids (also referred to as hearing prostheses or hearing instruments) for hard of hearing people or hearing enhancement devices for augmenting the hearing capability of normal hearing persons, as well as hearing protection devices designed to prevent noise-induced hearing loss. Due to the small size of such hearing devices the batteries employed therein are tiny and therefore often difficult to handle, e.g. when replacing a depleted battery with a new one, especially for elderly users with reduced dexterity. Hence, the use of rechargeable batteries which do not need to be removed from a device for recharging represent a considerable improvement for such users. Furthermore, such hearing devices are typically utilised for prolonged periods of time, e.g. during most of the day on a daily basis, so the batteries need to be replaced very often, for instance every few days. This puts a substantial financial burden on the users of such devices due to the considerable cost of the batteries required for operating them.

Therefore, the use of rechargeable batteries substantially reduces the operating costs of such hearing devices.

In particular hearing devices to be worn at least partially within an ear canal profit from using a built-in

rechargeable battery instead of a traditional single-use, disposable zinc air battery, because this relieves the user from having to perform the tedious task of replacing the very small, e.g. size 10A, batteries when they are empty. Rechargeable batteries are especially beneficial for hearing devices intended to be worn deeply within the ear canal, e.g. within the bony portion. Examples of such hearing devices are the Philips XP Peritympanic deep canal CIC aid, the Starkey Tympanette and SoundLens, the Songbird Flexfit disposable hearing aid, and Insound' s Lyric extended wear hearing aid. US 6,205,227 Bl also relates to a peritympanic hearing instrument, WO 00/32009 A2 relates to a semi-permanent canal hearing device, and WO 00/76271 Al relates to an extended wear canal hearing device. Such

P212795 deep-fitted hearing devices are typically worn constantly over a prolonged period of time, e.g. many days up to weeks, without being removed since their insertion and extraction is a tricky and quite awkward procedure

sometimes requiring the help of a specialist.

Consequently, the battery needs to be sealed into the hearing device in order to prevent sweat from disrupting battery operation. Hence, replacement of the battery is not possible and so it has to be rechargeable. Since the battery is built into the hearing device there is no need for a battery door to remove the battery, which helps to minimise the size of the hearing device.

For recharging the battery the hearing device needs to be linked to a battery charger. US 6,658,124 Bl describes a contact-free scheme using an inductive charging system for hearing devices. However, inductive charging suffers from a low degree of efficiency and has the disadvantage of requiring a large charging coil within the hearing device. Alternatively, electrical contacts are provided at the housing of the hearing device. WO 93/18629 Al describes a charging device for custom shaped rechargeable hearing prostheses with electrical contacts integrated in the housing in the form of two conducting surfaces. The charging device provides cavities for receiving the hearing prostheses, the cavities being formed according to the shape of the prostheses and having conductive terminals which are arranged so that electrical contact is

established with the conducting surfaces when the hearing prostheses are inserted into the cavities. The disadvantage of this solution is that the cavities in the charging device have to be adapted according to the custom shape of the user's hearing prostheses. US 2008/0118093 Al describes a contact element that is resiliently mounted at a hearing device and can be pressed onto a charging contact of an external charging device during charging under application of a positive force. The contact element is located in a first position during normal operation of the hearing device and is moved into a second position for charging. Alternatively, the charging device exhibits a receptacle adapted to the shape of the hearing device, and the contact element of the hearing device is pressed against the charging contact of the charging device when the hearing device is clamped into the receptacle by means of a clamp. US 2009/0067652 Al discloses a hearing device with at least one contact means, which can be flush with the hearing device housing during normal operation, and contacts a battery charging unit when in an extended or folded-out position during charging. With these prior art solutions where charging contacts are used for custom hearing devices, which are individually shaped according to the shape of the ear canal of the hearing device user, a precise positioning of the charging contacts and a secure connection of the charging contacts to a standardised battery charger is difficult to achieve. SUMMARY OF THE INVENTION

It is an object of the present invention to overcome the disadvantages of the prior art solutions and to provide a rechargeable hearing device with a coupling means allowing to easily and reliably couple the hearing device with a battery charger for charging a rechargeable battery

arranged within the hearing device. This object is reached by the hearing device according to claim 1.

It is a further object of the present invention to provide a hearing device charging system comprising an appropriate battery charger along with such a rechargeable hearing device. Such a hearing device charging system is specified in claim 10.

It is yet further object of the present invention to provide a method for charging such a rechargeable hearing device. Such a method is specified in claim 13.

Specific embodiments of the present invention are provided in the dependent claims.

The present invention is first directed to a hearing device to be worn at least partially within an ear canal,

comprising a microphone, an electronics unit, a receiver and a rechargeable battery, which are contained in a housing, wherein the hearing device features a coupling means for operationally connecting the battery to a battery charger, the coupling means comprising an inductor and a diode (i.e. rectifier means). A diode is a two-terminal electronic component with asymmetric conductance, i.e.

having low (ideally zero) resistance to current flow in one direction, and high (ideally infinite) resistance in the other. A first terminal of the diode is connected to a first input of a charging circuit, a first terminal of the inductor is connected to a second input of the charging circuit, and a second terminal of the diode is connected to a second terminal of the inductor.

The purpose of the coupling means is to provide a

power/energy coupling between a battery charger and the hearing device, so that electrical energy can be

transferred from a battery charger into the battery of the hearing device. However, unlike in a system employing electrodynamic induction where a magnetic field created by a primary coil of an inductive charger is coupled to a secondary coil located in the hearing device, in which secondary coil a current is induced, the first and second coil thereby forming a resonant transformer, the hearing device of the present invention employs an inductor with a closed-loop core, such as a toroidal ferrite core, which acts as an energy storage device, i.e. forms part of a tank circuit. With a toroidal core a minimum of the magnetic flux escapes outside the core, so it radiates less

electromagnetic interference than other shapes, which is especially advantageous in hearing device, where for instance the microphone would pick up such electromagnetic interference and the audio signal at its output would be disturbed thereby. The inductor may for instance be further contained within an electromagnetic shielding, such as an enclosure made of mu-metal, in order to further minimise the radiation of electromagnetic interference from the inductor.

In an embodiment of the hearing device the coupling means further comprises:

- a capacitor, or

- a dielectric structure at an outer surface of the

housing in contact with a conductive structure within the housing, jointly adapted to enable capacitive coupling of energy from outside the housing to the battery.

In this way, a complete galvanic isolation between the battery charger and the hearing device is achieved by employing a small capacitor or a part of a capacitor structure at the hearing device.

In a further embodiment of the hearing device the second terminal of the inductor is connected to an electrical contact, in particular via the capacitor, or to the conductive structure. In a further embodiment of the hearing device the housing comprises a face plate attached to the shell, wherein the face plate is at least partially comprised of a dielectric material, in particular the dielectric structure is

comprised in the face plate.

In a further embodiment of the hearing device the coupling means further comprises a magnetic connecting means. The magnetic coupling means allows to physically/mechanically connect/attach the hearing device with/to a battery

charger. This is therefore a further purpose of the coupling means to provide a physical connection between the hearing device and a battery charge.

In a further embodiment of the hearing device the magnetic connecting means, more particularly an electrically

conducting magnet, forms part of an electrical connection to the inductor. These features are directed to both the purposes of physically connecting as well as power

coupling.

In a further embodiment of the hearing device the magnetic connecting means is configured to magnetically engage with an external magnetic connecting counter-means such that the counter-means can be held at the hearing device at a predefined location and for instance with a predefined orientation. These features are especially directed to the purpose of physically connecting. In a further embodiment of the hearing device the face plate is non-detachably attached to the housing and the rechargeable battery is not removable from the housing.

In a further embodiment the hearing device is adapted to be liquid-_'tight, in particular to be waterproof.

In a further embodiment of the hearing device the hearing device is a completely-in-canal hearing device, more particularly a deep-fitting hearing device intended to be worn in a bony portion of the ear canal, even more

particularly an extended wear hearing device.

The present invention is further directed to a hearing device charging system comprising a battery charger and a hearing device, wherein the battery charger comprises a high-frequency generator/transmitter with a wire (e.g. an elongated wire as opposed to a large primary air coil used in conjunction with inductive charging) , wherein the wire features one of the following:

- an end of the wire is adapted to be physically/

mechanically connectable to an electrical contact of the hearing device, in particular by a magnetic connecting counter-means configured to magnetically engage with a magnetic connecting means of the hearing device; - an end of the wire is attached to a spatially extended conductive structure, such as a conductive plate or sheet, in particular suitable for accumulating

electrical charge, and adapted to form a capacitor structure together with a dielectric structure at an outer surface of a housing of the hearing device in contact with a conductive structure within the housing.

In this way the hearing device can be recharged either by using a single electrical contact or without any direct physical/mechanical connection to the battery charger by means of capacitive coupling.

In an embodiment the charging system further comprising a container for being filled with a liquid, such as a

cleaning solution, and for receiving the hearing device for recharging the battery, and for instance for

(simultaneously) cleaning the hearing device.

In a further embodiment of the charging system the

spatially extended conductive structure at least partly encompasses the container.

The present invention is further directed to method for charging a hearing device, the method comprising the steps of:

- generating a high frequency signal, in particular in a range from 1 kHz to 30 MHz, more particularly in a range from 10 kHz to 3 MHz, and applying the high frequency signal to a wire, and

either, as a first alternative,

- connecting an end of the wire to an electrical contact of the hearing device, a battery being connected to the electrical contact at least via an inductor and a diode; or, as a second alternative,

- capacitively coupling the high frequency signal with the hearing device (1) .

In this way an alternative method, for instance to

inductive charging is provided, where for example a small inductor with a closed-loop core, such as a toroidal ferrite core, acting as an energy storage device, i.e.

forming part of a tank circuit, is used instead of a larger (air) induction coil, as required for inductive charging. The inductor may for instance be contained within an electromagnetic shielding, such as an enclosure made of mu- metal, in order to minimise the radiation of

electromagnetic interference from the inductor.

In an embodiment of the first alternative of the method, connecting is established by a magnetic connecting counter- means configured to magnetically engage with a magnetic connecting means of the hearing device.

In an embodiment of the method, the hearing device is embedded in a medium having a relative permittivity s_r ≥ 3, in particular in the range 5 ≤ ε_Γ ≤ 88, more particularly in a range from 30 ≤ s_r ≤ 81.

In a further embodiment of the method, the medium is a liquid, such as for instance water or a cleaning solution, or the medium is part of a human head surrounding an ear canal, in particularly the hearing device is worn within the ear canal.

In an embodiment of the second alternative of the method, the step of capacitively coupling comprises the steps of:

- attaching an end of the wire to a spatially extended conductive structure, such as a conductive plate or sheet, in particular suitable for accumulating

electrical charge, and adapted to form a capacitor structure together with a dielectric structure at an outer surface of a housing of the hearing device in contact with a conductive structure within the housing;

- arranging the hearing device at the spatially extended conductive structure, in such a manner that capacitive coupling of the spatially extended conductive structure and the conductive structure within the housing is achieved, the battery being connected to the conductive structure within the housing at least via an inductor and a diode. In a further embodiment of second alternative of the method, the step of capacitively coupling comprises the steps of:

- inserting an end of the wire into a liquid, such as a cleaning solution, contained in a container;

- inserting the hearing device into the liquid, the

hearing device comprising a dielectric structure at an outer surface of a housing of the hearing device in contact with a conductive structure within the housing, and a battery of the hearing device being connected to the conductive structure within the housing at least via an inductor and a diode.

In a further embodiment of the second alternative of the method, the step of capacitively coupling comprises the steps of:

electrical charge, and adapted to form a capacitor structure together with a dielectric structure at an outer surface of a housing of the hearing device in contact with a conductive structure within the housing, wherein the spatially extended conductive structure at least partly encompasses a container containing a liquid, such as a cleaning solution, in particular is wrapped around the container; - inserting the hearing device into the liquid, a battery of the hearing device being connected to the conductive structure within the housing at least via an inductor and a diode.

It is pointed out that combinations of the above-mentioned embodiments give rise to even further, more specific embodiments according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further explained below by means of non-limiting exemplary embodiments and with reference to the accompanying drawings, which show:

Fig. 1 a high-level block diagram of a hearing device

coupled to a battery charger according to an exemplary embodiment of the present invention;

Fig. 2 a block diagram of a hearing device coupled to a battery charger according to a further exemplary embodiment of the present invention;

Fig. 3 a block diagram of a hearing device coupled to a battery charger according to another exemplary embodiment of the present invention;

Fig. 4 a block diagram of a hearing device coupled to a battery charger according to yet another exemplary embodiment of the present invention; Fig. 5 a block diagram of a hearing device charging system according to an exemplary embodiment of the present invention;

Fig. 6 a block diagram of a hearing device charging system according to a further exemplary embodiment of the present invention; and

Fig. 7 a schematic representation of a hearing device

charging system according to another exemplary embodiment of the present invention, where the hearing device is being charged whilst being worn within an ear canal.

In the figures, like reference signs refer to like parts.

DETAILED DESCRIPTION OF THE INVENTION

The hearing device 1 referred to in the following is a hearing device intended to be worn at least partly within an ear canal 60 of a user of the hearing device 1 (cf. e.g. Fig. 7), such as an in-the-ear (ITE) or a completely-in- canal (CIC) hearing device. It can be especially an extended wear hearing device for being worn deeply within the ear canal 60, for instance within the bony portion of the ear canal 60 for a prolonged period of time, e.g. a number of days. With reference to Fig. 1, such hearing devices comprise a microphone 25, an electronics unit 26 (e.g. a signal processing unit) , a receiver 27 (i.e. a miniature loudspeaker) and a power source such as a rechargeable battery 28, whereby these components are contained in a housing 2 of the hearing device 1. The housing 2 typically comprises an individually shaped custom shell and a standardised face plate 3 (cf. Fig. 4), which is adapted to fit onto the custom shell. The face plate 3 is usually glued to the shell or attached thereto in some other non-detachable manner, meaning that for example the rechargeable battery 28 is not removable from the housing 2 once it is assembled without destroying it.

As schematically depicted in the high-level block diagram of Fig. 1, the hearing device 1 further comprises a

coupling means 40 which allows it to be mechanically connected with or attached to the battery charger 5 as well as to be power/energy coupled (i.e. electrically) to the battery charger 5 with the aid of the coupling means 50 of the battery charger 5. Various embodiments of the coupling means 40 of the hearing device 1, both mechanical and electrical, will be described in the following.

A block diagram of a hearing device 1 coupled to a battery charger 5 according to a first embodiment of the present invention is depicted in Fig. 2. The battery charger 5 comprises a high-frequency (HF) signal generator, i.e. an HF transmitter 20 to which a (linearly) elongated wire 21 is connected. The distant end of the wire 21 is in turn connected with an electrical contact 6 at the housing 2 of the hearing device 1. Within the hearing device 1 the HF signal connected to the electrical contact 6 is applied to an inductor 14 and a diode 15. The diode 15 is used to rectify the HF signal. Hereby, a first terminal of the diode 15 is connected to a first input of a charging circuit 29, a first terminal of the inductor 14 is

connected to a second input of the charging circuit 29, and the second terminal of the diode 15 is connected to the second terminal of the inductor 14. Furthermore, the second terminal of the diode 15 and of the inductor 14 are either directly connected with the electrical contact 6 at the housing 2, or via a small capacitor 17 (as depicted in Fig. 2) in order to galvanically isolate the electrical contact 6 from the charging circuit 29. The advantage of this charging scheme is that only a single wire 21 and a single electrical contact 6 is required for connecting the charger 5 with the hearing device 1. In fact, when

implementing a shell and/or face plate 3 of a hearing device 1 using metal, e.g. titanium, the whole shell and/or face plate 3 can be employed a charging contact.

As shown in Fig. 3, the single wire 21 may have a magnet

16' at the end contacting a magnetic contact 16 comprising a ferromagnetic material such as a magnet at the hearing device 1. The magnetic attracting forces attaches the wire 21 to the electrical contact 6 of the hearing device 1, without the need to visually see the electrical contact 6 or to apply pushing forces to insert the wire 21 into a socket. This simplifies contacting and is especially useful for elderly users with reduced dexterity. In addition to the correct positioning it is also possible to ensure a certain preferred orientation of the hearing device 1 relative to the magnet 16' at the end of the wire 21. For instance this magnet 16' can be integrated into a charging cradle (not shown) adapted to receive the hearing device 1. By means of electrically conducting magnets the HF signal can be transferred from the wire 21 to the charging circuit 29.

In Fig. 4 an alternative embodiment of the coupling means 40, 50 are illustrated. Hereby, part of the housing 2 or part of a face plate 3 attached to the housing 2 is comprised of a dielectric material forming a dielectric structure 18 of a capacitor. The two conductive "plates" of this capacitor are formed by a conductive structure 19 located within the housing 2 or on the inner side of the face plate 3, and by a spatially extended conductive structure 22 to which the wire 21 is connected. The hearing device 1 can then for example simply be placed on a "charging" plate (i.e. the structure 22) for recharging the battery 28. With this embodiment of the charging system there is no need at all for charging contact on the surface of the housing 2 of the hearing device 1. This is an especially suitable charging arrangement for a completely encapsulated hearing device, such as is necessary to achieve a liquid tight, in particular a waterproof hearing device, whereby the microphone 25 and the receiver 27 are protected by means of acoustic transparent membranes. A first embodiment of a hearing device charging system is depicted in Fig. 5. Here a waterproof hearing device 1 is inserted into a container 23 filled with an electrically conducting liquid 24. In order to charge the battery 28 of the hearing device 1, the free end of the wire 21 is dipped into the liquid 24, which then conducts the HF signal from the battery charger 5 to the electrical contact 6 at the surface of the hearing device 1. In addition to charging the hearing device 1 it can also be cleaned by the liquid bath by employing a cleaning solution. This cleaning solution can be used to increase the conductivity of water to allow charging of the battery 28.

A second embodiment of a hearing device charging system is depicted in Fig. 6. Here the antenna 21 is not inserted into the liquid 24 but instead attached to a conductive plate 22 which is at least partly .wrapped around the container 23. The electrical energy of the HF signal from the battery charger 5 is capacitively coupled to the hearing device 1 for instance by means of the dielectric structure 18 comprised in the housing 2 or the face plate 3 which is in contact with the conductive structure 19 within the hearing device 1, acting as the second plate of a capacitor. In this embodiment the hearing device 1 can be pulled out of the liquid 24 by means of a "holding line" 30 which is connected to the hearing device 1 with the aid of magnetic connecting means 16, 16', however no energy is conveyed from the battery charger 5 to the hearing device 1 via the holding line 30. In Fig. 7 a schematic representation of a hearing device charging system according to an exemplary embodiment of the present invention is shown, where the hearing device 1 is being charged whilst being worn within an ear canal 60 of a user. The elongated wire 21 is connected to the hearing device 1 within the ear canal 60 by the magnetic connecting means 16', 16. In this case, the frequency of the HF signal should be higher than 1 MHz (up to 30 MHz) . The wire 21 together with the magnetic connection 16' , 16 thereby also allows pulling the hearing device 1 out of the ear canal 60. The battery charger 5 can for instance be worn behind the ear to provide energy from a primary battery to the rechargeable battery 28 within the hearing device 1. Alternatively, the wire 21 is connected to a conductive plate (22 not shown) worn at the ear, such that electrical energy is coupled to the hearing device 1 through liquid contained in the human tissue surrounding the hearing device 1 within the ear canal 60. In this case, the frequency of the HF signal could be at lower frequencies, e.g. at 100 kHz.

The above embodiments have the following advantages:

- Less mechanical problems (vibrations, dropping and

wearing out of coupling means) .

- No oxidation problems and no isolation switch is needed.

Therefore the problems with humidity and oxidation between the contacts and sealing are avoided. Even when contact is oxidised the capacitive coupling still works.

- No leakage current will occur, because there is no

direct current (DC) conductive connection. - No skin irritations occur because there is no leakage current and therefore galvanic effects will not take place on the skin.

Claims

1. A hearing device (1) to be worn at least partially within an ear canal (60), comprising a microphone (25), an electronics unit (26), a receiver (27) and a rechargeable battery (28), which are contained in a housing (2), wherein the hearing device (1) features a coupling means (40) for operationally connecting the battery (28) to a battery charger (5), characterised in that the coupling means (40) comprises an inductor (14) and a diode (15), wherein a first terminal of the diode (15) is connected to a first input of a charging circuit (29) , a first terminal of the inductor (14) is connected to a second input of the

charging circuit (29) , and a second terminal of the diode (15) is connected to a second terminal of the inductor (14) .

2. The hearing device (1) of claim 1, wherein the coupling means (40) further comprises: - a capacitor (17), or

- a dielectric structure (18) at an outer surface of the housing in contact with a conductive structure (19) within the housing, jointly adapted to enable capacitive coupling of energy from outside the housing to the battery (28) .

3. The hearing device (1) of claim 1 or 2, wherein the second terminal of the inductor (14) is connected to an electrical contact (6) , in particular via the capacitor (17), or to the conductive structure (19) .

4. The hearing device (1) of claim 2 or 3, wherein the housing (2) comprises a face plate (3) attached to the housing (2), and wherein the face plate (3) is at least partially comprised of a dielectric material, in particular the dielectric structure (18) is comprised in the face plate ( 3) .

5. The hearing device (1) of one of claims 1 to 4, wherein the coupling means (40) further comprises a magnetic connecting means (16) .

6. The hearing device (1) of claim 5, wherein the magnetic connecting means (16) , more particularly an electrically conducting magnet, forms part of an electrical connection to the inductor (14) .

7. The hearing device (1) of claim 5 or 6, wherein the magnetic connecting means (16) is configured to

magnetically engage with an external magnetic connecting counter-means (16') such that the counter-means (16') can be held at the hearing device (1) at a predefined location and for instance with a predefined orientation.

8. The hearing device (1) of one of claims 1 to 7, wherein the hearing device (1) is adapted to be liquid-tight, in particular to be waterproof.

9. The hearing device (1) of one of claims 1 to 8, wherein the hearing device (1) is a completely-in-canal hearing device, more particularly a deep-fitting hearing device intended to be worn in a bony portion of the ear canal, even more particularly an extended wear hearing device.

10. A hearing device charging system comprising a battery charger (5) and a hearing device (1) of one of claims 1 to 9, wherein the battery charger (5) comprises a high- frequency generator/transmitter (20) with a wire (21) , wherein the wire (21) features one of the following:

- an end of the wire (21) is adapted to be physically

connectable to an electrical contact (6) of the hearing device (1) , in particular by a magnetic connecting counter-means (16') configured to magnetically engage with a magnetic connecting means (16) of the hearing device (1) ;

- an end of the wire (21) is attached to a spatially

extended conductive structure (22), such as a conductive plate or sheet, in particular suitable for accumulating electrical charge, and adapted to form a capacitor structure together with a dielectric structure (18) at an outer surface of a housing of the hearing device (1) in contact with a conductive structure (19) within the housing .

11. The charging system of claim 10, further comprising a container (23) for being filled with a liquid (24), such as a cleaning solution, and for receiving the hearing device (1) for recharging the battery (28), and for instance for cleaning the hearing device (1) .

12. The charging system of claim 11, wherein the spatially extended conductive structure (22) at least partly

encompasses the container (23) .

13. A method for charging a hearing device (1) comprising the steps of:

- generating a high frequency signal, in particular in a range from 1 kHz to 30 MHz, more particularly in a range from 10 kHz to 3 MHz, and applying the high frequency signal to a wire (21) , and

either, as a first alternative,

- connecting an end of the wire (21) to an electrical

contact (6) of the hearing device (1), a battery (28) being connected to the electrical contact (6) at least via an inductor (14) and a diode (15);

or, as a second alternative, - capacitively coupling the high frequency signal with the hearing device (1) .

14. The method according to the first alternative in claim 13, wherein connecting is established by a magnetic

connecting counter-means (16') configured to magnetically engage with a magnetic connecting means (16) of the hearing device (1) .

15. The method of claim 13 or 14, wherein the hearing device (1) is embedded in a medium having a relative permittivity 8_r ≥ 3, in particular in the range 5 ≤ 8_r ≤ 88, more particularly in a range from 30 ≤ s_r ≤ 81.

16. The method of claim 15, wherein the medium is a liquid, such as for instance water or a cleaning solution, or wherein the medium is the part of a human head surrounding an ear canal (60), in particularly the hearing device (1) is worn within the ear canal (60) .

17. The method according to the second alternative in claim 13, wherein the step of capacitively coupling comprises the steps of:

- attaching an end of the wire (21) to a spatially

extended conductive structure (22), such as a conductive plate or sheet, in particular suitable for accumulating electrical charge, and adapted to form a capacitor structure together with a dielectric structure (18) at an outer surface of a housing (2) of the hearing device (1) in contact with a conductive structure (19) within the housing (2 ) ; - arranging the hearing device (1) at the spatially

extended conductive structure (22), in such a manner that capacitive coupling of the spatially extended conductive structure (22) and the conductive structure (19) within the housing is achieved, the battery (28) being connected to the conductive structure (19) within the housing at least via an inductor (14) and a diode (15) .

18. The method according to the second alternative in claim 13, wherein the step of capacitively coupling comprises the steps of:

- inserting an end of the wire (21) into a liquid (24), such as a cleaning solution, contained in a container (23);

- inserting the hearing device (1) into the liquid (24), the hearing device (1) comprising a dielectric structure

(18) at an outer surface of a housing of the hearing device (1) in contact with a conductive structure (19) within the housing, and a battery (28) of the hearing device (1) being connected to the conductive structure

(18) within the housing at least via an inductor (14) and a diode (15) .

19. The method according to the second alternative in claim 13, wherein the step of capacitively coupling comprises the steps of:

— attaching an end of the wire (21) to a spatially

extended conductive structure (22), such as a conductive plate or sheet, in particular suitable for accumulating electrical charge, and adapted to form a capacitor structure together with a dielectric structure (18) at an outer surface of a housing of the hearing device (1) in contact with a conductive structure (19) within the housing, wherein the spatially extended conductive structure (22) at least partly encompasses a container (23) containing a liquid (24), such as a cleaning solution, in particular is wrapped around the container (23);

- inserting the hearing device (1) into the liquid (24), a battery (28) of the hearing device (1) being connected to the conductive structure (19) within the housing at least via an inductor (14) and a diode (15) .