EP2894880B1 - Antenna device for hearing instruments - Google Patents

Description

The invention relates to an antenna device for hearing instruments, in particular for hearing instruments to be worn in the auditory canal.

Hearing instruments can be designed for example as hearing aids. A hearing aid is used to supply a hearing-impaired person with acoustic ambient signals that are processed and amplified for compensation or therapy of the respective hearing impairment. It consists in principle of one or more input transducers, of a signal processing device, of an amplification device, and of an output transducer. The input transducer is typically a sound receiver, e.g. a microphone, and / or an electromagnetic receiver, e.g. an induction coil. The output transducer is usually as an electroacoustic transducer, z. As miniature speaker, or as an electromechanical transducer, z. B. bone conduction, realized. He is also referred to as a handset or receiver. The output transducer generates output signals that are routed to the patient's ear and are intended to produce a hearing sensation in the patient. The amplifier is usually integrated in the signal processing device. The hearing aid is powered by a battery integrated into the hearing aid housing. The essential components of a hearing aid are usually arranged on a printed circuit board as a circuit carrier or connected thereto.

Hearing instruments can also be designed as hearing aids as so-called tinnitus maskers. Tinnitus maskers are used to treat tinnitus patients. They produce from the respective hearing impairment and depending on the principle of action also dependent on ambient noise acoustic output signals that can contribute to reducing the perception of annoying tinnitus or other ear noises.

Hearing instruments can also be designed as telephones, mobile phones, headsets, headphones, MP3 players or other telecommunications or consumer electronics systems.

Hereinafter, the term hearing instrument is understood to mean both hearing aids and tinnitus maskers, comparable such devices, as well as telecommunications and consumer electronics systems.

Hearing instruments, in particular hearing aids, are known in various basic types. In ITE hearing aids (in-the-ear, also IDO or in-the-ear), a housing containing all functional components including microphone and receiver is at least partially carried in the ear canal. Completely-in-Canal (CIC) hearing aids are similar to ITE hearing aids, but are worn fully in the ear canal. In BTE hearing aids (behind-the-ear, or behind-the-ear or IDO), a housing with components such as battery and signal processing device is worn behind the ear and a flexible sound tube, also referred to as a tube, directs the acoustic output signals of a receiver from the housing to the ear canal, where often an ear piece is provided on the tube for reliable positioning of the tube end in the ear canal. RIC-BTE hearing aids (receiver-in-canal behind-the-ear) are similar to BTE hearing aids, but the receiver is carried in the ear canal and instead of a sound tube, a flexible earpiece tube conducts electrical signals instead of acoustic signals to the receiver, which is at the front of the earpiece tube attached, usually in a reliable positioning in the ear canal serving ear piece. RIC-BTE hearing aids are often used as so-called open-fit devices, in which the auditory canal remains open for the passage of sound and air to reduce the disturbing occlusion effect.

Deep-fit hearing aids (deep-ear canal hearing aids) are similar to CIC hearing aids. However, while CIC hearing aids are typically worn in a more distal (distal) section of the external auditory canal, deep-fit hearing aids continue to be advanced to the eardrum (proximal) and at least partially carried in the inner portion of the external ear canal. The external portion of the ear canal is a skin-lined canal connecting the pinna to the eardrum. In the outer portion of the external auditory canal, which adjoins directly to the auricle, this channel is formed of elastic cartilage. In the inner portion of the external auditory canal, the canal is formed by the temporal bone and thus consists of bone. The course of the ear canal between cartilaginous and bony sections is usually angled in a (second) kink and includes a different angle from person to person. In particular, the bony portion of the ear canal is relatively sensitive to pressure and contact. Deep-fit hearing aids are at least partially worn in the delicate bony section of the ear canal. When advancing into the bony portion of the ear canal, they must also pass the mentioned second kink, which can be difficult depending on the angle. In addition, small diameter and tortuous shapes of the ear canal can further complicate advancement.

In addition to the hearing aid types with acoustic receiver to be worn on or in the ear, cochlear implants and Bone Anchored Hearing Aids (BAHA) are also known.

All types of hearing aids have in common that the smallest possible housing or designs are sought in order to increase the comfort, optionally to improve the implantability and possibly to reduce the visibility of the hearing aid for cosmetic reasons. The aim of the smallest possible design also applies to most other hearing instruments.

Modern hearing instruments exchange control data via a usually inductive radio system. The required transmission data rates for binaurally coupled hearing instruments are rising sharply, if moreover acoustic information for audiological algorithms (eg beamforming, sidelook, etc.). A higher data rate requires a larger bandwidth. One of the main factors influencing the sensitivity of the transmission system to interfering signals is precisely the bandwidth.

With the high and individual packing density, especially in IDO hearing instruments, hearing instrument-internal interference signal sources are the main problem. With an increase in the bandwidth, this still increases. In typical IDO hearing instruments, the antenna is arranged on or partially in the so-called faceplate (the wall of the hearing instrument facing away from the eardrum). The antenna is then typically in the immediate vicinity of the so-called hybrid (hybrid integrated circuit carrier) and the receiver. The hybrid and the receiver emit magnetic and electric fields that can greatly affect transmission.

The arrangement of the antenna relative to receiver and hybrid is crucial to the performance of the transmission system. Due to the high packing density, a mutual shielding of the components is necessary. The hybrid is typically wrapped with a shield box for this purpose. The receiver gets a screen foil or is specially designed so that it is magnetically tight.

In the older, not previously published patent application of the Applicant DE 10 2013 204 681.2 (Filing date 18.03.2013) is proposed to arrange the antenna instead of the faceplate in the eardrum facing part of the hearing instrument. As a result, a positioning is achieved, which reduces the influence of the transmission system by hybrid and receiver.

In the WO 2013/135307 A1 For a hearing aid, an antenna is proposed which comprises a hollow core of a magnetically permeable material. The hollow core has an axial passage. In Axialdurchgang is in particular a tube arranged, which is connected to the sound outlet of a receiver.

Next will be in the DE 10 2007 042 590 A1 proposed to provide components of a hearing aid with an electromagnetic shielding, so that an antenna for transmitting electromagnetic signals from interference of these components is shielded. This can be dispensed with an additional component for shielding.

For the transmission link, it is somewhat simplified that the distance between the bridged distance is shortened for the same antenna and the same energy requirement but increased bandwidth. Although it would be possible to build the antenna more efficiently, this is typically only possible by increasing the antenna volume. One way of improving the transmission link, however, is to design the antenna so that a volume is used that would otherwise be idle broke. This results in an enlargement of the antenna and thus an increase in efficiency, without the need to additionally create more space in the hearing instrument.

The object of the invention is to specify a hearing instrument, in particular an IDO hearing instrument, which specifies a transmission bandwidth-improved data transmission system with no or only insignificantly increased space and energy requirements.

The invention solves this problem by an antenna device and by a hearing instrument with the independent claims.

A basic idea of the invention consists in an antenna device for a hearing instrument comprising an antenna arrangement with a coil core of magnetically permeable material which has a preferred transmission and reception spatial direction, and a further electrical hearing instrument component, the electromagnetic interference radiation emitted, wherein between the antenna arrangement and the other hearing instrument component, an at least partially planar screen of magnetically permeable material is arranged, and wherein the screen is arranged transversely to the longitudinal axis of the antenna array with a distance of 50 to 150 micrometers to the spool core. The optimum distance results on the one hand from the fact that with increasing distance the signal-to-noise ratio of the antenna initially increases and then decreases again, with a maximum of the order of 100 micrometers. On the other hand, the screening effect between the antenna and the further hearing aid component initially increases with increasing distance, and then passes into saturation at a distance of the order of magnitude of 100 micrometers. In addition, a minimum distance should be maintained because of the overall size.

With transverse is meant an orientation perpendicular or approximately perpendicular or in an angular range of a few degrees around 90 ° to each other. In this case, due to different housing shapes whose shape is determined by the ear canal, a certain tilt between the antenna and the screen are allowed, for example, in an angular range of 45 ° around the transverse orientation. In this case, a tilting relative to the transverse orientation disadvantageously reduces the sensitivity of the antenna.

The orientation refers to the longitudinal axis of the antenna arrangement and the area given by the screen. The screen can either be a plate, or a U-shaped angled plate, or a kind of cup, in which the other hearing instrument component can be inserted. On the one hand, the two-dimensional shield effects a shielding of the electromagnetic fields and thereby already reduces the mutual interference coupling. High magnetic permeability enhances the shielding effect. In addition, the screen causes due to the high permeability of the material in the end, as it were an extension of the antenna or an increase in their efficiency. This raises a higher Transmission field strength and a higher reception sensitivity.

An advantageous development of the basic idea is that the material of the coil core has a lower magnetic permeability than the material of the screen. The higher magnetic permeability of the screen material enhances the screening effect without having a significant negative impact on the performance of the antenna due to the typically higher loss angle of the highly permeable material.

A further advantageous development of the basic idea is that the screen consists of mu-metal foil. By using a per se conventional Mu metal foil with their particular high magnetic permeability good processability can be achieved with very good shielding at the same time.

A further advantageous development of the basic idea is that the screen is adhesively bonded to the antenna arrangement. As a result, a particularly uncomplicated installation is given.

A further advantageous development of the basic concept consists in that the further electrical hearing instrument component emits the electromagnetic interference radiation predominantly in an interference radiation spatial direction, and that the antenna arrangement and the further hearing instrument component are arranged transversely to one another in such a way that interfering radiation is coupled into the interference radiation Antenna arrangement is reduced. By predominantly, it is meant that the radiation intensity of the interfering radiation in the Störstrahlungs spatial direction is higher than in any other spatial direction. In this case, the lowest coupling results when the two spatial directions are oriented perpendicular to each other, so that with transverse orientation perpendicular or approximately perpendicular or in an angular range of at most 45 ° greater or less than 90 ° to each other.

More precisely, the orientation refers to the respective magnetic field, so that the respective fields are oriented transversely to each other and the respective magnetic fields as well. The main directions of the fields are not readily determinable theoretically, so that the main direction is not clearly established. In addition, a small tilt relative to the transverse orientation due to the asymmetry of the fields caused thereby can have an advantageous effect on the shielding between component and antenna. The optimal orientation of the component results theoretically at 90 °, but must be determined depending on the component and its actual field in each case. In principle, a tilting of the component is less disadvantageous or even advantageous in comparison to a tilting of the screen, so that larger tilting of the component would generally be provided independently of the screen.

The reduction of the interference couplings in the antenna arrangement allows a higher transmission and reception bandwidth with constant volume and energy requirements. The further hearing instrument component may be a receiver or another, in particular inductive or electromagnetic radiation emitting component.

An advantageous development of the basic idea is that the antenna arrangement comprises a coil antenna, that the further hearing instrument component comprises a coil arrangement which emits the interference radiation, and that the coil antenna and the coil arrangement with respect to their respective longitudinal direction transversely to each other, that is perpendicular or approximately perpendicular or in an angular range around 90 °, are oriented. The magnetic field of a coil antenna has a pronounced spatial orientation, so that a significant reduction of the mutual interference coupling is achieved by the orientation transversely to each other.

A further advantageous development is that the further hearing aid component is arranged on the screen. The arrangement of the hearing instrument component so close to the antenna arrangement with a reasonably low mutual interference coupling is made possible in particular by the mutual shielding. This results in a space-saving arrangement, which is also suitable for the pre-assembly of the antenna assembly and the other hearing instrument component.

A further advantageous development is that the further hearing aid component is attached to the screen. The attachment of the hearing instrument component to the screen together with the antenna assembly forms a preassembled module. This simplifies the further assembly or production of the hearing instrument.

A further advantageous development consists in that the screen surrounds the further hearing instrument component in the direction away from the antenna core at least in a region of its circumference. As a result, the effectiveness of the shield is further increased and the interference coupling in particular of the further component in the antenna arrangement is further reduced. Furthermore, this increases the sensitivity and the quality of the antenna.

A further advantageous development consists in that the further hearing instrument component is a receiver and that the coil core and the shield have a sound channel passing through the coil antenna. With an IDO hearing instrument, both components can be placed as deep as possible in the ear canal to save space. Thus, an acoustically advantageous placement of the receiver is achieved as close to the eardrum, while the coil antenna is reached close to the IDO hearing instrument of the other (right or left) ear of the user, which positively affects the quality of mutual data transmission. It has In practice, it has been shown that the sound channel does not result in any significant deterioration of the antenna properties in the relevant field strength range.

The receiver is an electrodynamic transducer and thus the receiver contains a magnetic circuit which has an excitation winding. In operation, the receiver is typically fed with a pulse density modulated signal having spectral components in the frequency band of the data transmission system. This control is very energy efficient and is therefore used in hearing instruments. The spectral components can not be avoided without a strong increase in the energy requirement of the hearing instrument. The receiver is the largest consumer in the hearing instrument. In contrast, the energy requirements of the Datenübertragungssytems is very small and, accordingly, its receiving sensitivity to magnetic interferers is quite large.

By arranging the receiver transversely to the antenna, the magnetic circuit and thus also the receiver winding is oriented perpendicularly or approximately perpendicular or in an angular range around 90 ° to the antenna. This greatly reduces the coupling of the receiver winding to the antenna. The antenna can thus be placed much closer to the receiver.

The combination of the transversal receiver and the antenna is optimized for the tapered shell contour at the tip of the IDO hearing instrument, minimizing the installation length. The placement at the tip of the IDO hearing instrument increases the fitting rate and reduces the size of the hearing instrument. In addition, more freedom in the positioning of the faceplate is possible because the antenna is no longer located at or near the faceplate. Further eliminates the effort to plan a suitable position of the antenna at or near the faceplate, as the tip of the IDO hearing instrument represents a pre-given position. This also eliminates the consideration of physical Restrictions, such as magnetic field disturbances, that are required when placed in the area of the faceplate.

Since the receiver winding is not centrally located to the receiver, which is structurally usually not feasible, and since the housing easily deforms the field lines, is still very close to the antenna is still a sturgeon coupling. The interference coupling to the antenna can be reduced by the additional shielding between antenna and receiver. The shield covers preferably (best space / performance ratio) the whole area of the receiver. By arranged in the immediate vicinity with a small distance to the antenna core screen, the field lines of the excitation winding of the receiver are concentrated returned, so that only a very small number of field lines passes through the antenna windings. It is prevented that current is induced in the antenna winding, and thus noise interference is greatly reduced by the receiver. The shield makes additional measures, such as screen foil, and their installation unnecessary.

The combination of shield and coil core not only serves to shield, but also increases the sensitivity of the antenna. One could therefore reduce the antenna length due to the effect of the screen even with constant sensitivity.

Another advantage of the shield in the common arrangement with the antenna is that with the same inductance, the required number of turns can be reduced, so that in turn the diameter of the single turn, typically enameled wire, can be increased. Due to the low number of turns and the larger wire diameter advantageously the electrical winding resistance is reduced, whereby the antenna quality is increased.

To increase the noise decoupling, the screen can also extend around the edges of the receiver. Therefor All four edges of the receiver and their permutations are conceivable and bring about a greater or lesser amplification of the decoupling effect. The receiver could be enveloped laterally or even completely in order to further improve the shielding effect. This further improves the antenna sensitivity and quality.

The field line concentration and thus the field strength of the antenna is reduced by the screen at the exit to the receiver. The low field strength causes in the metal surface of the receiver less eddy currents, thereby increasing the quality of the antenna. Therefore, with the same quality, the distance between the antenna and the receiver can be shortened. This effect is reinforced by the hole in the ferrite, as the field lines are concentrated at the edge in the flange area.

A further advantageous development of the basic idea is that the coil core has a sound channel and the screen has a sound opening, and that the sound channel and the sound opening are arranged in alignment so that a continuous sound channel is formed. The sound channel makes it possible, in particular, for a receiver to be provided as a further hearing instrument component. The acoustic output signal of the receiver can then be led directly into the sound channel. Of course, even if the other hearing instrument component is not a receiver, the acoustic output signal of a receiver arranged at another location can be passed through the sound channel. This makes it particularly unnecessary to provide a separate sound channel, so that further space is avoided.

A further advantageous development is that the inner wall of the sound channel and / or the side facing away from the coil core of the screen is covered with sound-absorbing material. The sound insulation causes a favorable for the use of the receiver vibration decoupling. By the sound insulation in the module of coil core, coil antenna and Receiver is integrated, a further pre-assembly and thus a further simplification of the further assembly and production of the hearing instrument is achieved. In addition, the distance caused by the sound insulation between the receiver and the screen causes the decoupling of the screen and receiver in a distance required to increase the antenna quality, in which the transmission of the antenna field into the receiver is reduced by the distance. The farther the receiver is enclosed by the screen, the lower the distance can be selected without a reduction of the antenna quality.

As explained above, a basic idea of the invention is to design the antenna so that it can be placed closer to another hearing instrument component without losing performance. For this purpose, an antenna device is specified, which integrates various functions, such as shielding, contacting, etc ... in a small space. The arrangement makes it possible in particular to manage without additional space and without additional components.

In addition, the antenna can additionally be placed very close to the hearing instrument component and combined as an integrated module. This simplifies installation. The arrangement of the receiver to the antenna is fixed and there is only one instead of two components. There are no separate steps for the installation of the antenna required. There are also no additional components for a separate installation necessary. Instead, the antenna module is a part that can be pre-assembled automatically before production.

Fig 1

IDO-Hörinstrument Stand der Technik

Fig 2

IDO-Hörinstrument mit Antenneneinrichtung

Fig 3

Antenneneinrichtung schematisch

Fig 4

Antennen-Receiver-Modul

Fig 5

Antennen-Receiver-Modul mit versetzter Antenne

Fig 6

Antennen-Receiver-Modul mit verkipptem Receiver

Fig 7

Feldlinienverlauf Receiver

Fig 8

Feldlinienverteilung Receiver mit Abschirmung

Fig 9

Tube

Fig 10

Antennen-Receiver-Modul

Fig 11

Signal-Rausch-Abstand über Schirmungsabstand

Fig 12

Störsignal-Dämpfung über Schirmungsabstand

Fig 13

Feldlinienverlauf Antennenfeld

Fig 14

Feldlinienverlaus Receiverfeld

Further advantageous embodiments will be apparent from the dependent claims and from the following description of exemplary embodiments with reference to figures. The figures show:

Fig. 1

IDO hearing instrument prior art

Fig. 2

IDO hearing instrument with antenna device

Fig. 3

Antenna device schematically

Fig. 4

Antenna Receiver Module

Fig. 5

Antenna receiver module with staggered antenna

Fig. 6

Antenna receiver module with tilted receiver

Fig. 7

Field line receiver

Fig. 8

Field line distribution receiver with shielding

FIG. 9

tube

FIG. 10

Antenna Receiver Module

Fig. 11

Signal-to-noise ratio across shielding distance

FIG. 12

Noise attenuation via shielding distance

Fig. 13

Feldlinienverlauf antenna field

FIG. 14

Feldlinienverlaus Receiverfeld

In Fig. 1 An IDO hearing instrument of the prior art is schematically illustrated. The IDO hearing instrument 3 is inserted into the external auditory canal of the hearing instrument wearer. It is located partly in the outer cartilaginous part 1 of the ear canal, and is partially advanced to the bony part of the ear canal. It is therefore a CIC hearing instrument, depending on how far the hearing instrument is inserted into the ear canal, it could also be a deep-fit hearing instrument.

In the hearing instrument 3, a receiver 4 is placed at the end facing the eardrum. This emits acoustic signals to the eardrum via a sound channel 7. Arranged on the faceplate arranged at the opposite end is a hybrid circuit carrier 8 which comprises a signal processing device, not shown, as well as an amplifier for generating control signals for the receiver 4. An antenna 6 is also disposed on the faceplate 5 and oriented so that it is oriented in the direction of the opposite, not dargstellten the ear of the hearing instrument wearer. The antenna 6 is used for data transmission between the two binaural hearing instruments of the hearing instrument wearer, wherein only one of the two hearing instruments is shown.

It can be seen that the antenna is arranged relatively close to the other electronic components of the hearing instrument 3, so that electromagnetic interference signals from these can couple into the antenna 6. Such interference signals are emitted in particular by the receiver 4, which has an inductive receiver coil which serves to convert electrical signals into acoustic signals.

In addition, the signals that the antenna 6 transmits or receives on the way to the opposite ear or hearing instrument of the hearing instrument wearer to pass the receiver 4, which additionally adversely affects the data transmission path. The interference mentioned reduce the performance of the data transmission system sensitive, so that a high bandwidth with low energy consumption is limited achievable.

In Fig. 2 an IDO hearing instrument with antenna device is shown schematically. The housing 19 of the IDO hearing instrument 13 tapers on the side of the eardrum to support. A sound channel 17 on this side serves to deliver acoustic signals to the eardrum of the wearer.

On the opposite side of the hearing instrument 13 is closed by a faceplate 15, in addition to a battery, not shown, and microphones, not shown, a hybrid circuit substrate 18 (dashed lines) inside the hearing instrument 13 and its housing 19 is arranged. The hybrid circuit carrier 18 comprises a signal processing device and an amplifying device, which controls the likewise arranged in the interior of the housing 19 Receiver 14. The receiver 14 generates acoustic output signals that are output via the sound channel 17.

The receiver 14 is oriented transversely to the longitudinal axis of the hearing instrument 13. Between Receiver 14 and the eardrum oriented, tapered end of the hearing instrument 13 is the antenna 16 for data transmission between the two binaural hearing instruments of the hearing instrument wearer. The antenna 16 is oriented in the longitudinal direction of the hearing instrument 13 and thus aligned transversely to the receiver 14. It is separated from Receiver 14 by a screen 26. The screen is arranged transversely to the antenna 16 and at a small distance from its (not shown) spool core. It has a sound opening 39, which is arranged in alignment with the sound channel 17. The distance is between 50 and 150 microns.

The transverse orientation of the receiver 14 causes a space-saving arrangement of receivers 14 and antenna 16, whose overall length is reduced by the transverse arrangement of the receiver 14. In addition, the transverse arrangement of the receiver 14 results in a better utilization of space in the tapered part of the housing 19. The space available in the tapered tip of the housing 19 is thus better utilized than would be the case with a longitudinally arranged receiver. In the event that the sound output of the housing 19 is not in a straight line with the sound channel 17 in the antenna 16, a bent preformed sound tube can be connected to the antenna 16 on the output side, which leads to the sound output.

In Fig. 3 the antenna device is again shown schematically. The sound channel 17 is located within the antenna 16, and passes therethrough to the receiver 14. The receiver 14 is oriented as described above transverse to the antenna 16 and to the longitudinal direction of the IDO hearing instrument. Between the (not shown) coil core of the antenna 16 and the Reveicer 14 at a distance of 50 to 150 micrometers to the bobbin, the screen 26 is arranged. The distance may be effected, for example, by a preformed part on which the screen 26 and the antenna 16 are mounted; the distance can also be effected in a particularly simple manner, that screen 26 and antenna 16 by means an adhesive layer of suitable thickness are glued together.

For explanation only, a longitudinally arranged receiver 20 is shown by dashed lines. The dashed arrangement of the receiver 20 illustrates that the overall length increases with longitudinal arrangement of the receiver 20, and that at the same time results in no tapered contour of the arrangement. As explained above, it is illustrated that with longitudinal arrangement of the receiver 20, the space in the tapered tip of the hearing instrument 13 can not be exploited equally well.

In Fig. 4 An antenna receiver module is shown in perspective. The receiver 14 is, as explained above, oriented transversely to the antenna 16. The antenna 16 is disposed on a spool core 22 made of permeable material. The permeable coil core 22 thus serves in the usual way to increase the antenna surface or sensitivity.

At a distance of 50 to 150 micrometers to the end of the spool core 22 towards the receiver 14, the screen 26 is arranged (the distance is not visible in the figure). The screen 26 is predominantly planar in shape and oriented transversely to the orientation of the antenna 16, ie parallel to the orientation of the receiver 14. The surface of the screen 26 is dimensioned so that the receiver 14 completely or almost completely over the entire screen 26 facing surface by the shield 26 is shielded from the antenna or, conversely, the antenna 16 is shielded from the receiver 14.

The sound channel 17 extends through the coil core 22 and through the screen 26 to the receiver 14. The coil core 22 is covered on the inside by a tube 21 formed as a sound-insulating or vibration-damping material. In an alternative embodiment, the spool core 22 need not be covered on the inside vibration-damping and would then serve as a non-insulated sound guide. In order to a larger cross section of the sound channel can be achieved. The tube 21 surrounds the sound channel 17 from the antenna-side output to the receiver 14 and is formed there parallel to the screen 26 areally. The receiver 14 is mounted on the surface-shaped part of the tube 21 and thus also vibration isolated. Round extensions of the sound or vibration damping material are used in addition to the device integrated vibration-decoupled suspension of the device in the housing of the hearing instrument.

The coil core 22 forms, together with the tube 21, the antenna 16, the screen 26 and the receiver 14, an antenna receiver module. The tube 21 may be shaped such that, in arrangements of the shield 26 and the spool core 22 on the tube 21, the above-mentioned distance between the shield 26 and the spool core 22 results. The module can be pre-installed or pre-assembled in the hearing instrument. The pre-assembly of the antenna receiver module on the tube 21 reduces the assembly effort in the manufacture of the hearing instrument and thus simplifies the manufacturing process.

In Fig. 5 is shown one of the foregoing representation similar embodiment. In this respect, the same reference numerals are used for the same components and reference is made to the preceding explanations. In contrast to the embodiment explained above, however, the coil core 22 together with the antenna 16 is not arranged in the middle of the screen 26, but shifted (in the illustration above). This may serve to adapt the outer shape of antenna 16 and receiver 14 to the mounting space available in a hearing instrument.

In Fig. 6 another embodiment similar to the previous illustrations is shown. Again, like reference numerals are used and reference is made to the preceding explanations. In contrast to the previously explained embodiment, the receiver 14 is tilted relative to the screen 26. Again, this may be due to customization serve the mounting space available in a hearing instrument. Depending on the orientation of the dynamic fields of receiver 14 and antenna 16, the shielding effect of the screen 26 may vary at low tilt angles of the receiver 14, under favorable circumstances even be improved with respect to an exactly vertical arrangement.

In Fig. 7 the field line profile of a receiver coil operating receiver is shown schematically and greatly simplified. In the receiver 14, a receiver coil 23 is arranged axially, that is, oriented in the longitudinal direction. It can be seen that the receiver coil 23 generates a strongly compressed (magnetic) field in the axial direction, while it generates a relatively weak (magnetic) field in the radial direction, that is, in the figure to the right and left. As a rule, however, the field of the receiver 23 is greatly influenced and more complexly shaped by its housing and possibly one or more further receiver coils and magnetic components.

It can be seen that the magnetic field generated by the receiver 14 is more pronounced in its longitudinal direction than in its transverse direction. Thus, the arrangement explained above, in which the antenna susceptible to electromagnetic interference is not arranged longitudinally but transversely to the receiver, already effects a clear decoupling of the electromagnetic signals of the receiver 14 from said antenna. The improved decoupling is thus achieved in that the antenna is arranged both laterally from and transversely to the receiver 14.

In Fig. 8 the field line profile of the receiver is shown with shielding. The receiver 14 is arranged in the illustration on the left on the above-explained screen 26 of the permeable coil core 22. On the other side of the screen 26, the spool core 22, which is slightly spaced apart from this, as described above, carries the antenna 16.

The illustrated field line profile illustrates the shielding of the antenna 16 from the receiver 14 or from the signals of the receiver coil 23. The field lines running in the direction of the antenna 16 are deformed by the shield 26 and extend through it. The field line density in the screen 26 is thus increased while simultaneously reducing the field line density beyond the screen 26. In other words, the strength of the (magnetic) field generated by the receiver coil 23 at the location of the coil 16 is reduced considerably. Thus, interference couplings of receiver signals in the antenna 16 are considerably reduced.

In FIG. 9 the above-described sound-insulating tube is shown separately. The tube 21 is traversed longitudinally from the sound channel. A coil section 24 is provided to receive the previously explained coil core 22. The coil core 22 is arranged around the coil section 24, possibly also around the further longitudinal course of the tube 21 around. A screen section 25 is provided to receive the screen. In this case, the screen is placed on one side of the screen section 25, while a receiver is arranged on the opposite side of the screen section 25. The illustrated tube 21 is made entirely of sound insulating material, for example in a conventional manner from Viton.

In FIG. 10 a further embodiment of the antenna receiver module is shown. At a distance of 50 to 150 micrometers to the spool core 32, a screen 37 is arranged on one side as explained above. An antenna 36 is wound on the spool core 32. On the side remote from the antenna 36, the screen 37 surrounds the receiver 34 arranged there, at least in the region shown in the figure above and below. For this purpose, the screen 37 is designed there cup-shaped, so that the receiver 34 surrounded by the screen 37 at least in an area of the screen circumference in the direction away from the antenna 36 direction.

A particularly good shielding results when the screen 37 surrounds the receiver 34 on all sides. A further improvement of the shielding can be achieved in that the screen 37 encloses the receiver 34 completely and not only laterally. This results in a further improvement of the antenna, which can either be used to increase the bandwidth, or to make a shortening of the antenna while maintaining performance.

The coil core 32 passes through a sound channel 17 which is covered by the continuous tube 31 with sound-absorbing material. The sound channel 17 is arranged in alignment with the sound opening 40 of the screen 37. The sound opening 40 and the sound channel 17 thus together form a continuous sound channel. The tube 31 is also flat or cup-shaped in the area of the screen 37 and receives the receiver 34 in a vibration-damping manner. The receiver 34 is attached to the tube 31. The illustrated receiver antenna module can be pre-assembled, so that the further assembly and manufacture of the hearing instrument is considerably simplified.

In Fig. 11 the course of the signal-to-noise ratio (SNR) of the antenna signal is shown as a function of the above-explained distance between the screen and the coil core of the antenna. It can be seen that the signal-to-noise ratio has a maximum at about 100 to 200 microns distance. From the course it follows that a certain minimum distance between the screen and the coil core is advantageous.

In FIG. 12 the attenuation of the interfering signals of the receiver for the antenna signal in dependence on the above-explained distance between the screen and the coil core of the antenna is shown. It can be seen that the attenuation converges to a maximum attenuation at about 100 microns distance. From the course it follows that a certain minimum distance between the screen and the coil core is advantageous.

From the synopsis of the diagrams explained above (signal-to-noise ratio over distance, interference signal attenuation over distance), it follows that a certain minimum distance (approximately less than 100 micrometers) between screen and coil core is advantageous, but that advantage decreases with increasing distance a certain further distance (about 200 microns) does not increase further or even decreases again. Against a further increase in the distance is the desire to achieve the smallest possible design of the antenna receiver assembly.

From the considerations explained above, a distance between the screen and the coil core of about 50 to 150 micrometers, which is advantageous for antenna properties and size, results. It can also be seen from the diagrams that the narrower range of about 75 to 100 micrometers is particularly advantageous. It is obvious that different values can result after individual design of antenna, coil core, screen and receiver. In the case of constellations typical for hearing instruments, however, it can be assumed that they are within the specified value ranges.

In Fig. 13 the magnetic field of the antenna in and around the spool core 22 is shown schematically. The shield 26 spaced from the coil core 22 causes a recognizable compression of the magnetic field on the side of the coil core 22 and the antenna. Due to the permeable properties of the receiver 14, which is itself permeable, a part of the magnetic field is also passed through it, which advantageously even causes a theoretical extension of the antenna and thus contributes to improving the sensitivity.

Not shown in the figure, the deformation of the field line through the screen 26 results in that the field lines run longer overall in the coil core 22 and screen 26 together. This advantageously results in an increase in sensitivity. Next it can be seen that between screen 26 and receiver 14 sets a reduction in the field lines coming from the antenna, because the field lines amplified at the edge of the screen 26 and not approximately between screen 26 and receiver 14 exit. At the same time the screen has no adverse effect on the stray field.

In FIG. 14 the magnetic field of the receiver 14 is shown schematically. The screen 26, which is at a distance from the coil core 22, has a clear effect of shielding the magnetic field of the receiver 14 for the antenna or the coil core 22. It can be seen that part of the magnetic field penetrates the screen 26, but only the smallest part thereof passes into the spool core 22 over the distance.

The field lines extending in the direction of the antenna are deformed by the screen 26 and pass therethrough. The field line density in the screen 26 is thus increased while simultaneously reducing the field line density beyond the screen 26. In other words, the strength of the (magnetic) field generated by the receiver coil at the location of the coil is significantly reduced. This significantly reduces noise interference from receiver signals into the antenna.

Simulations have shown that although the field of the receiver 14 can take on a very different shape over time, the good shielding effect remains essentially constant.

Claims (12)

1. Antenna device for a hearing instrument (13), comprising an antenna arrangement (16, 36) with a coil core (22, 32) made of magnetically permeable material, having a preferred transmission and reception spatial direction, and a further electric hearing instrument component which emits electromagnetic disturbance radiation, wherein an at least partly planar screen (26, 37) made of magnetically permeable material is arranged between the antenna arrangement (16, 36) and the further hearing instrument component,
   characterized
   in that the screen (26, 37) is arranged across the longitudinal axis of the antenna arrangement (16, 36) and in that the screen (26, 37) is arranged at a distance of 50 to 150 micrometres, preferably 75 to 100 micrometres, from the coil core (22, 32).
2. Antenna device according to Claim 1,
   characterized in that the material of the coil core (22, 32) has a lower magnetic permeability than the material of the screen (26, 37).
3. Antenna device according to Claim 2,
   characterized in that the screen (26, 37) consists of a mu-metal film.
4. Antenna device according to one of the preceding claims,
   characterized in that the screen (26, 37) is adhesively bonded to the antenna arrangement (16, 36).
5. Antenna device according to one of the preceding claims,
   characterized in that the further electric hearing instrument component emits the electromagnetic disturbance radiation predominantly in a disturbance radiation spatial direction, and in that the antenna arrangement (16, 36) and the further hearing instrument component are arranged transversely to one another in such a way that coupling of disturbance radiation into the antenna arrangement (16, 36) is reduced.
6. Antenna device according to one of the preceding claims,
   characterized in that the antenna arrangement (16, 36) comprises a coil antenna, in that the further hearing instrument component comprises a coil arrangement (23) which emits the disturbance radiation, and in that the coil antenna and the coil arrangement (23) are oriented transversely to one another in respect of the respective longitudinal direction thereof.
7. Antenna device according to one of the preceding claims,
   characterized in that the further hearing instrument component is arranged at the screen (26, 37).
8. Antenna device according to Claim 7,
   characterized in that the further hearing instrument component is fastened to the screen (26, 37).
9. Antenna device according to one of the preceding claims,
   characterized in that, in at least a region of the circumference thereof, the screen (26, 37) surrounds the further hearing instrument component in the direction facing away from the antenna arrangement (16, 36).
10. Antenna device according to one of the preceding claims,
    characterized in that the coil core (22, 32) comprises a sound channel (17) and the screen (26, 37) comprises a sound opening (26), and in that the sound channel (17) and the sound opening (26) are arranged flush with one another in such a way that a continuous sound channel is formed.
11. Antenna device according to Claim 10,
    characterized in that the inner wall of the sound channel (17) and/or the side of the screen (26, 37) facing away from the coil core (22, 32) is covered by sound-damping material.
12. Hearing instrument comprising an antenna device according to one of the preceding claims.

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