EP1011295A2 - Hermetically tight hearing aid transducer and hearing aid with this transducer - Google Patents

Abstract

The electroacoustic transducer has an electromechanical transducer drive unit (19) in a housing (14) hermetically sealed on all sides with one wall forming a flexible membrane (17). The drive unit is coupled to the membrane so that mechanical output vibrations of the unit are directly coupled to the membrane from the interior and stimulate it to flexural vibrations that cause sound radiation. An Independent claim is also included for a hearing aid.

Description

Hörer" bezeichnet wird. Dieser elektroakustische Hörer strahlt das verstärkte akustische Signal in den Gehörgang des betreffenden Ohres ab. Der Gehörgang wird in vielen Fällen durch ein individuell angefertigtes Ohrpaßstück (sog. Otoplastik") abgedichtet, um einerseits eine akustische Druckkammer anzunähern, die durch das Restvolumen bis zum Trommelfell gebildet wird, und um andererseits akustische Rückkopplungen zwischen Mikrofon und Hörer bei großen Verstärkungsgraden zu vermeiden. Grundsätzlich existieren zwei verschiedene Bauformen solcher Hörgeräte:

• Hinter-dem-Ohr-Hörgerät " (HdO): alle wesentlichen Elemente des Hörgerätes wie Mikrofon, elektronische Einheit, Batterie und Hörer befinden sich in einem gemeinsamen Gehäuse, das hinter dem Ohr getragen wird. Das verstärkte Schallsignal wird mittels eines Schalleitungsschlauches aus dem Hörer ausgekoppelt und über die Ohrmuschel zum Ohrpaßstück geführt und durch dieses hindurch in den Gehörgang eingespeist. Das Hörgerät kann auch an einem Brillengestell montiert sein.
• In-dem-Ohr-Gerät " (IdO): alle oben genannten Elemente des Hörgerätes befinden sich in einem gemeinsamen Gehäuse, das in der Ohrmuschel im Bereich des äußeren Gehörgangs getragen wird. Ein solches In-dem-Ohr-Gerät ist beispielsweise in das individuelle Ohrpaßstück integriert oder stellt durch eine entsprechende äußere Bauform das Ohrpaßstück selbst dar. In der In-dem-Ohr-Bauart entfällt der Schallzuleitungsschlauch, da sich die Schallaustrittsöffnung an der dem Gehörgang zugewandten Seite des Hörgerätes befindet und der Hörer das verstärkte Schallsignal somit direkt in den Gehörgang abstrahlt.

Hearing aids for the rehabilitation of inner ear damage record the sound with a microphone and convert the sound with this microphone into an electrical signal. This signal is processed and amplified analog or digital by a subsequent electronic unit. The amplified electrical signal is generally fed to an electroacoustic transducer that functions as a loudspeaker and also as

This electro-acoustic receiver emits the amplified acoustic signal into the auditory canal of the ear in question. In many cases, the auditory canal is made using an individually manufactured earpiece (so-called Otoplastik ") sealed, on the one hand to approximate an acoustic pressure chamber, which is formed by the remaining volume up to the eardrum, and on the other hand to avoid acoustic feedback between the microphone and the listener at high amplification levels. Basically, there are two different designs of such hearing aids:

• Behind-the-ear hearing aid "(BTE): all essential elements of the hearing aid, such as the microphone, electronic unit, battery and handset, are located in a common housing that is worn behind the ear. The amplified sound signal is removed from the handset using a sound tube uncoupled and guided over the auricle to the earpiece and fed through it into the ear canal. The hearing aid can also be mounted on a spectacle frame.
• In-the-ear device "(ITE): All of the above-mentioned elements of the hearing aid are located in a common housing which is worn in the auricle in the area of the external auditory canal. Such an in-the-ear device is, for example, in the Individual earmold integrates or represents the earmold itself due to a corresponding outer design. In the in-the-ear design, the sound supply tube is omitted, since the sound outlet opening is located on the side of the hearing aid facing the auditory canal and the listener thus directly into the amplified sound signal emits the ear canal.

• Die Lautsprecher (Hörer) der überwiegenden Mehrheit aller Hörgeräte beruhen aus Gründen des elektrischen Wirkungsgrades und der daraus resultierenden Optimierung der Batterielebensdauer auf dem elektromagnetischen Wandlungsprinzip. Daraus folgt ein unvermeidliches Auftreten nichtlinearer Verzerrungen insbesondere bei hohen Wandlerströmen und zugehörigen Ausgangspegeln, die zu Lasten der übertragenen Klangqualität gehen.
• Weiterhin liegt die erste mechanische Resonanzfrequenz dieser Wandler meist in der Mitte des spektralen Übertragungsbereiches; daraus und aus weiteren physikalischen und konstruktionsbedingten Gründen resultiert ein nicht ebener Frequenzgang und damit eine Welligkeit des Ausgangsschalldruckpegels. Durch diese Resonanzen innerhalb des Übertragungsbereiches sind prinzipiell auch Phasendrehungen bedingt; beide Aspekte tragen zur Minderung der Übertragungsgüte bei.
• Die Wandler (Hörer) sind aufgrund des zu übertragenden akustischen Schallsignals mechanisch ausgangsseitig offen", d.h., die Außenluft kann bis aufwenige Fälle von zusätzlichen Strömungssieben relativ ungehindert bis ins Innere des Wandlers eindringen. Somit ist der Wandler nahezu ungeschützt allen Witterungs- und sonstigen Umwelteinflüssen, insbesondere Luftfeuchtigkeit ausgesetzt. Diese Umwelteinflüsse sind zu einem hohen Prozentsatz verantwortlich für häufig auftretende deutliche Minderungen der Wandlerbetriebsparameter oder sogar das Versagen und damit Ausfallen dieses technischen Bauelementes.
• Insbesondere bei den In-dem-Ohr-Geräten führt aufgrund der örtlichen Anordnung des Hörers im äußeren oder (bei maximal miniaturisierten Geräten) inneren Gehörgang die Verschmutzung des akustischen Zugangskanals durch Ohrenschmalz, der das Produkt eines natürlichen Reinigungsprozesses des Gehörgangs ist, zu Beinträchtigungen bzw. Ausfällen des Hörers und damit des Hörgerätes.

In principle, hearing aids of both types mentioned above have the following disadvantages:

• The loudspeakers (earphones) of the vast majority of all hearing aids are based on the electromagnetic conversion principle for reasons of electrical efficiency and the resulting optimization of battery life. This results in the inevitable occurrence of nonlinear distortion, particularly at high converter currents and associated output levels, which are detrimental to the transmitted sound quality.
• Furthermore, the first mechanical resonance frequency of these transducers is usually in the middle of the spectral transmission range; this and other physical and design-related reasons result in a non-flat frequency response and thus a ripple in the output sound pressure level. In principle, phase resonances are also caused by these resonances within the transmission range; both aspects help to reduce the quality of transmission.
• The transducers (listeners) are mechanically output-side due to the acoustic sound signal to be transmitted open ", ie the outside air can penetrate into the interior of the converter relatively unhindered except for a few additional flow screens. The converter is therefore almost unprotected from all weather and other environmental influences, in particular exposed to atmospheric moisture. These environmental influences are responsible for a high percentage of common significant reductions in the converter operating parameters or even the failure and thus failure of this technical component.
• Particularly in the case of in-the-ear devices, due to the location of the listener in the outer or (in the case of maximally miniaturized devices) inner ear canal, the contamination of the acoustic access channel by ear wax, which is the product of a natural cleaning process of the ear canal, leads to impairments or Failure of the handset and thus the hearing aid.

The present invention has as its object the known disadvantages mentioned above To minimize or eliminate hearing aid converters to a large extent

This is achieved according to the invention by an electroacoustic transducer for hearing aids, which is characterized in that an electromechanical transducer drive unit is accommodated in an all-round hermetically gas-tight, preferably metallic housing, the wall of which is designed as a flexible, preferably circular membrane, and that The converter drive unit is coupled to the housing membrane in such a way that mechanical vibrations on the output side of the converter drive unit are mechanically directly coupled to the housing membrane from the inside, thereby stimulating the membrane to produce bending vibrations which cause sound radiation outside the converter housing. The housing membrane provides the sound radiating to the outside The internal electromechanical transducer drive unit can be based on all known transducer principles, such as, in particular, piezoelectric, dielectric, electromagnetic, electrodynamic and magnetostrictive.

The converter housing is preferably cylindrical, in particular circular cylindrical, designed, and it expediently has a housing part open on one side, the open side of the transducer membrane is hermetically sealed.

The housing part and / or the transducer membrane can be made of a non-corrosive rustproof metal, especially stainless steel, or from a non-corrosive, rustproof and particularly body-compatible metal, in particular titanium, platinum, niobium, tantalum or their alloys.

The housing part is preferably hermetically gas-tight with at least one pole electrical housing bushing provided, the ground potential expedient lies on the housing part. The housing bushing can be advantageous based on gas-tight soldered metal-ceramic connections and as an insulator Aluminum oxide ceramic and at least as an electrical feedthrough conductor have a platinum-iridium wire.

A piezoelectric is preferably used as the electromechanical converter drive unit Ceramic disc is provided, which in particular be circular can and that on the inside of the transducer membrane as electromechanically active Element is applied and together with the transducer membrane an electromechanical represents active heteromorph composite element. It is like one Bimorph element uses the piezoelectric cross effect, only the partner of Composite here not from a second piezoelectrically active element, but from the passive transducer membrane with a geometry similar to that of the piezo element. The piezoelectric ceramic disc can be used on both sides with a very thin, as Electrode surface serving, electrically conductive coating and consist in particular of lead zirconate titanate. If an electric field is applied to the placed piezoelectric ceramic disc, the disc changes due to the transverse piezo effect their geometry preferably in the radial direction. There an expansion or radial contraction due to the mechanical a firm bond with the passive transducer membrane is prevented, one results Deflection of the composite element, which with appropriate edge support Membrane in the middle is maximum.

The thickness of the transducer membrane and the thickness of the piezoelectric ceramic disk are appropriately approximately the same size and are in the range of 0.05 mm to 0.15 mm. Also preferably have the transducer membrane and the piezoelectric one Ceramic disc approximately the same modulus of elasticity. A particularly simple and reliable construction is obtained if both the transducer membrane and the housing part are electrically conductive, the piezoelectric ceramic disc with the Transducer membrane electrically conductive due to an electrically conductive adhesive is connected, and the housing part one of at least two electrical transducer connections forms. The radius of the transducer membrane is advantageous by a factor of 1.2 to 2.0, preferably a factor of about 1.4, larger than the radius of the piezoelectric ceramic disc.

According to a modified embodiment of the invention, the electromechanical converter drive unit designed as an electromagnet arrangement, which is a component fixed with respect to the converter housing and a has a vibratable component that with the inside of the transducer membrane is coupled. By using the electromagnetic converter principle, a Particularly favorable frequency response for the low frequencies of the listening area Transducer can be achieved so that an adequate listening impression with sufficient Volume level is made possible even with low electrical voltages.

The vibratable component of the electromagnet arrangement is preferably in the essentially fixed in the center of the transducer membrane. In particular, with the Inside the transducer membrane is a permanent magnet that forms the vibratable component be connected while an electromagnetic coil is in the converter housing is firmly attached to the permanent magnet in vibrations offset. The permanent magnet can expediently be designed as a magnetic pin, and the coil may be a ring coil with a central opening into which the Immersed magnetic pen. In this way, a transducer arrangement with special My moving mass received the changes to that applied to the solenoid electrical signal can follow quickly and faithfully. Basically, it is also possible to attach the solenoid to the vibratable membrane and the To fix magnets with reference to the converter housing.

Regardless of the transducer principle provided in the individual case is preferred by choosing the mechanical properties of the converter membrane and the converter drive unit that the oscillating system comprising these components is coordinated that the first mechanical resonance frequency of the entire transducer is spectrally at upper end of the transmission range, advantageously in the range from 4 to 12 kHz, especially around 10 kHz. The converter drive unit is preferably electrically controlled so that the deflection of the transducer membrane up to first resonance frequency is impressed independent of frequency.

A converter driver can also be accommodated in the converter housing.

The invention further relates to a hearing aid which is the output side Sound transducer an electroacoustic transducer of the type explained above having. Such a hearing aid can in particular be used as a behind-the-ear device, in-the-ear device or glasses device.

Regardless of the hearing aid type, the electroacoustic transducer can be used together with a microphone, a power supply, signal processing and amplifying Elements as well as any other for a hearing aid function necessary components in a hearing aid housing.

The electroacoustic can also be independent of the hearing device type Converter housed in a separate housing and by at least one bipolar electrical line connected to the actual hearing aid, which in in a conventional manner, a microphone, a power supply, signal processing and reinforcing elements as well as any other for a hearing aid function contains necessary components. This can be advantageous for the electroacoustic Separate housing containing transducers can be integrated into an earmold. The earmold containing the electroacoustic transducer can be fitted with a behind-the-ear hearing aid mechanically via a flexibly deformable coupling element be connected, the individual adaptation to the anatomy of the outer ear permitted and contains the electrical lead to the converter.

When installing the electroacoustic transducer in an earmold or directly in an in-the-ear device the transducer housing is advantageously arranged so that the transducer membrane at least approximately flush with the area of the earmold or the in-the-ear device housing that faces the ear canal.

The hearing aid is preferably equipped with an electronic converter driver, which the signal processing electronics of the hearing aid to the selected Electromechanical principle of the converter-internal converter drive unit respective objectives of the output level and frequency range accordingly adjusts. The converter driver can in the signal processing electronics of the Hearing aid integrated or a separate electronic module. In the latter Case, the driver module in the hearing aid housing or the Transducer housing housed or between the hearing aid and the electro-acoustic Be arranged converter. When arranged outside the hearing aid housing Driver module can be expedient for the electrical supply of the driver module the electrical from the hearing aid based on the principle of phantom power Connection between the hearing aid electronics and the driver module be bipolar and a direct voltage are superimposed on a signal-containing alternating voltage, that supplies the driver module. The driver module can be detachable mechanical or electrical connectors with the hearing aid or the electroacoustic transducer.

The hearing aid can be designed fully digital and a pulse width modulated Have output stage, the converter driver for connecting the pulse width modulated Output stage has an integrating function.

Fig. 1

einen schematischen Längsschnitt, der den prinzipiellen Aufbau eines erfindungsgemäßen Hörgerätewandlers erkennen läßt;

Fig. 2

einen schematischen Längsschnitt eines Hörgerätewandlers mit piezoelektrischer Antriebseinheit;

Fig. 3

einen schematischen Längsschnitt eines Hörgerätewandlers mit elektromagnetischer Antriebseinheit,

Fig. 4

ein Beispiel für die Mittelpunktsauslenkung der Wandlermembran eines erfindungsgemäßen Hörgerätewandlers über der Frequenz;

Fig. 5

schematisch ein mit einem erfindungsgemäßen Hörgerätewandler ausgestattetes In-dem-Ohr-Hörgerät;

Fign. 6 und 7

schematisch ein mit einem erfindungsgemäßen Hörgerätewandler ausgestattetes Hinter-dem-Ohr-Hörgerät;

Fig. 8

schematisch eine abgewandelte Ausführungsform eines mit einem erfindungsgemäßen Hörgerätewandler ausgestatteten Hinter-dem-Ohr-Hörgerätes; sowie

Fign. 9 bis 11

drei Ausführungsbeispiele für die elektronische Signalaufbereitung von erfindungsgemäßen Hörgeräten.

Advantageous exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Show it:

Fig. 1

a schematic longitudinal section that shows the basic structure of a hearing aid converter according to the invention;

Fig. 2

a schematic longitudinal section of a hearing aid transducer with a piezoelectric drive unit;

Fig. 3

2 shows a schematic longitudinal section of a hearing aid converter with an electromagnetic drive unit,

Fig. 4

an example of the center point deflection of the transducer membrane of a hearing aid transducer according to the frequency;

Fig. 5

schematically shows an in-the-ear hearing device equipped with a hearing aid converter according to the invention;

Fig. 6 and 7

schematically shows a behind-the-ear hearing aid equipped with a hearing aid transducer according to the invention;

Fig. 8

schematically shows a modified embodiment of a behind-the-ear hearing aid equipped with a hearing aid transducer according to the invention; such as

Fig. 9 to 11

three exemplary embodiments for the electronic signal processing of hearing aids according to the invention.

In Fig. 1 is the basic structure of the electroacoustic designated overall with 15 Hearing aid converter shown schematically. Here is the housing or the earmold of an in-the-ear or behind-the-ear device represented by a wall 12, in which the hearing aid transducer 15 is inserted in such a way that its sound-emitting membrane 17 at least approximately as flush as possible with the housing or earmold area locks that faces the ear canal. The hearing aid converter 15 has a converter housing 14 that is closed on all sides, preferably a circular cylinder, whose upper side in the drawing is formed by the transducer membrane 17. The preferably made of non-corrosive metals (e.g. stainless steel, titanium, platinum, niobium, Tantalum or its alloys) membrane 17 hermetically seals the open side of a housing part 13 which is open on one side is gastight, except for the membrane 17 are all walls of the converter housing 14 mechanically rigid.

The membrane 17 is in the area of the membrane center by a mechanically rigid Connecting element 18 connected to a converter drive unit 19. This converter drive unit 19 represents the actual electromechanical transducer, which via the Connecting element 18 excites the membrane 17 to dynamic bending vibrations lead to sound radiation on the outside of the converter housing 14. The Interpretation of the mechanical parameters, especially the dynamic mass fractions and the rigidity of the membrane 17, the connecting element 18 and the converter drive unit 19 expediently so that the first mechanical Resonance frequency is spectrally at the upper end of the desired transmission range (Tuning converter 15). With appropriate electronic control (Voltage or current injection depending on the converter principle of the converter drive unit 19) is the deflection of the membrane 17 below the first resonance frequency independent of frequency.

The electrical signal for the converter drive unit 19 is supplied via a hermetically gas-tight electrical introduced into the converter housing 14 Feedthrough 16 with electrical converter connections 16a, which are exemplary in FIG. 1 are shown bipolar. The electrical converter connections 16a can go directly to the Converter drive unit 19 lead or, as shown in Fig. 1, to one of the converter drive unit 19 upstream electrical or electronic converter drivers 66, which is housed in the converter housing 14 as an example in FIG. 1. The Converter driver 66 prepares unit 19 depending on the electromechanical conversion principle and the parameters of the driving electrical signal at terminals 16a thereof Electrical control signal on The converter driver 66 generally serves as an adaptation component between an electronic unit 65 of the one explained in more detail below Hearing aid 10 or 11 (Fig. 5, 6, 7 and 8) and the transducer 15. This electronic Adaptation component advantageously allows the use of existing ones electronic circuits of existing hearing aids, so that a completely new development of these circuits can be avoided. The converter driver 66 can, depending on what is used Conversion principle of the converter drive unit 19 contain components that have a further reinforcing character, the supply voltage range over Increase the corresponding DC / DC converter, an electrical impedance matching make and the like. The supply of the driver 66 with electrical operating energy is advantageously carried out on the principle of electrical phantom power, the a direct voltage component is superimposed on the signal-carrying line. So there is only one bipolar connection between the electronic unit 65 of the hearing aid and the Transducer element 15 necessary. In principle, the driver 66 can also be omitted and the corresponding electronic adjustments can be made in the hearing aid itself be carried out, so that in particular for an in-the-ear application according to FIG. 1 the volume requirement of the converter 15 can be minimized.

A preferred embodiment of the converter 15 is shown schematically in FIG. 2 This is advantageously circular and metallic housing part 13 in cross section one-sided through the likewise metallic transducer membrane 17, for example through a Welded connection, hermetically sealed gas-tight. On the inside of the membrane 17 sits a thin, piezoceramic disc, which is connected to the membrane 17 by means of a electrically conductive adhesive connection is in a mechanically strong connection. This Piezo disk represents the electromechanical transducer element and thus the transducer / drive unit 19. The connecting element 18 from FIG. 1 is the flat one in this case Adhesive connection between the piezo disc and the membrane. About the electrical, hermetic tightly inserted signal bushing 16, the piezo disc is on the one hand on the internal electrode surface contacted (represented by a schematic Wire connection 16c). On the other hand, the piezo disk is contacted on the outer electrode surface over the metallic converter housing 14, since this via the conductive adhesive to the external electrode surface of the Piezo disk is electrically connected. The electrical connection between one of the two Connections 16a with the metallic housing 14 are made by a conductive Contacting element 16b.

If an electrical alternating signal is applied to the connections 16a, this is due to the transverse piezoelectric effect a rotationally symmetrical dynamic Bending of the membrane 17 perpendicular to the membrane plane to that described Sound radiation through the membrane 17 leads. In the embodiment according to FIG. 2, by way of example, does not include a converter driver circuit 66 as in FIG. 1 to illustrate the low overall height of the entire transducer 15 due to the piezoelectric Drive element is realizable. This converter embodiment is suitable therefore constructively in particular for the installation variants explained below Hearing aid corresponding to FIGS. 5 and 8.

FIG. 3 shows a further suitable embodiment of the hearing aid converter 15 shown, in which the electromechanical transducer drive unit 19 on the electromagnetic principle. The converter 15 in turn has a converter housing 14 with a preferably cylindrical and mechanically rigid housing part 13, on its one end face, the preferably circular, bendable membrane 17 is hermetically sealed. With the transducer membrane 17 is on the inside and in the middle a rod-shaped permanent magnet 21 mechanically firmly connected to the low Air gap in a central central opening 22a of an electromagnetic toroid 22 protrudes and which forms the converter drive unit 19 together with the coil 22. The sink 22 (shown in FIG. 3 as an air coil) is mechanically fixed to the converter housing 14 connected and to the poles 16a of the hermetically sealed bushing 16 electrically connected.

When an AC voltage is applied to the coil 22, the magnet 21 experiences one dynamic deflection perpendicular to the membrane plane and displaces the membrane 17 thus to mechanical bending vibrations around the rest position. This in turn leads to the desired sound radiation to the outside.

Even in the case of this converter embodiment, it is not an electronic converter driver (corresponding to the driver 66 in FIG. 1) within the housing 14. It understands but it turns out that such a driver with appropriate geometric design in the Hearing aid converter 15 can be integrated. Furthermore, the magnetic field guidance and thus the efficiency of the converter by using appropriate components inside the converter housing 14 made of suitable ferromagnetic materials appropriate geometry design to be optimized. Such a converter design can with a suitable design of the coil parameters have the advantage that an existing one electronic hearing aid circuit including those driving the transducer Output stage can be connected directly (e.g. with Class D power amplifiers that integrating function of electromagnetic transducers).

4 schematically shows the desired course of the center deflection x _{W of} the transducer membrane 17 over the frequency f regardless of the chosen implementation principle of the transducer-internal transducer drive unit 19 in the event that the transmission bandwidth should reach at least 10 kHz. It can be seen that the first mechanical resonance frequency 23 is approximately 10 kHz, ie at the upper end of the range sought in this example. The higher resonances 24 (modes) are thus also outside the transmission range. This so-called up-tuning also results in a largely frequency-independent course of the emitted sound pressure in the auditory canal, provided that the ear mold described below acoustically seals the external auditory canal sufficiently. Due to the lack of higher modes in the transmission range, the phase response up to the first resonance frequency 23 remains flat; that is, there are no phase shifts, which also contributes significantly to the unadulterated reproduction of the amplified audio signal and thus to the overall transmission quality of the hearing aid.

The transducer 15 is preferably arranged in a housing 12 of the hearing aid in such a way that it is located on the housing area facing the ear canal. 5 are exemplary the installation and use of the converter described in one shown schematically in total with 11 in-the-ear hearing aid. That with the hearing aid housing 12 provided in-the-ear hearing aid 11 sits in a known manner in the Concha of the outer ear 5. Sound passes through a Sound entry opening 55 into the hearing aid 11 and is inserted into a by means of a microphone 60 electrical signal converted. This signal is in an electronic unit 65 edited and reinforced. The hearing aid 11 is powered by a battery 70 with electrical Operating energy supplied. The processed and amplified signal is the converter 15th supplied with the transducer membrane 17 directly in the ear canal 30 facing end of the housing 12 of the in-the-ear hearing aid 11 is arranged. The generated by the transducer membrane 17, amplified sound signal is directly in the Ear canal 30 emitted. It vibrates the eardrum 35, which leads to a Lead auditory impression. The hearing aid 11 sits acoustically as close as possible in the auditory canal 30, the front transducer 15 emitted sound signal into an approximate acoustic Pressure chamber fed by the residual volume of the ear canal and the Eardrum is formed. As described above, is the deflection of the transducer membrane 17 to the spectral upper end of the acoustic transmission range The sound pressure level generated in the auditory canal 30 is also frequency-independent frequency-independent and with low ripple as required.

After the transducer membrane 17, as shown in Fig. 1, the hearing aid housing 12 of the Hearing aid 11 seals tightly and the transducer 15 itself through the transducer membrane 17th is hermetically sealed, no dirt or ear wax can escape from the Ear canal 30 penetrate into hearing aid 11 or transducer 15. Against humidity is basically the converter 15 due to the hermetically gastight embodiment protected. In addition, the transducer membrane 17 can be wiped with damp media can be easily cleaned.

FIGS. 6 and 7 show the possible installation of the transducer 15 in a behind-the-ear hearing device (BTE) 10 shown schematically. The principally necessary components 55, 60, 65 and 70 correspond to those of the embodiment of FIG. 5. Die Transducer membrane 17 of transducer 15, which in turn is at the end of hearing aid housing 12 is arranged, in this case the acoustic signal radiates into an open channel Carrying hook 20. A sheathing line hose 50 is mechanical on these carrying hooks 20 connected, which leads the amplified sound signal to the ear canal. This is in Fig. 6 shown schematically. The formwork line hose 50 opens into a mostly individual shaped earmold 25 (earmold) that is as acoustically tight as possible in the inlet opening of the ear canal sits. The sound signal is transmitted through a hole in the otoplastic 25 the ear canal behind and the eardrum.

8 shows a further embodiment of a behind-the-ear hearing device 10 under Use of the present converter type is shown schematically. The converter 15 itself is housed in the earmold 25, which in its design known earmolds of a behind-the-ear hearing aid or the shape of a housing In-the-ear device corresponds to the individual anatomical conditions of the Outer ear 5 is adjusted. The transducer 15 is inserted into the earmold 25 that the sound-emitting transducer membrane 17 again at the outer end of the fitting 25 lies, which faces the ear canal 30 and thus the eardrum 35. Between the actual hearing aid housing 12, which is worn behind the auricle 5 and that is a microphone, a corresponding electronic unit and a battery contains, and the converter 15 is a purely electrical connection, which in Fig. 8 as electrical converter feed line 40 is shown. The line 40 in one is advantageous mechanical lead piece 45 out, which is conveniently made of plastic and is geometrically permanently deformable to allow individual adaptation to the outer ear anatomy to enable.

Another practical, advantageous embodiment of this type of supply line can consist in that the lead piece 45 is not connected to the hearing device 10 and / or the converter 15 is mechanically and electrically firmly connected, but detachable plug connections 46 having. In the event of a possibly necessary replacement, you can then simply Only the transducer 15, or the transducer 15 and the earmold 25, or only that Supply piece 45 or all components are replaced. The detachable plug connections 46 can in a particularly advantageous manner in the EP-A-0 811 397 known manner.

The embodiment described with reference to FIG. 8 has compared to that in FIGS. 6 and 7 Form shown the advantage that the transducer 15, the processed sound signal as in 5 radiates directly into the auditory canal 30 and thus the known acoustic defects of a supply hose 50 (see FIG. 6) avoided become. Nevertheless, the advantage of a behind-the-ear design with a larger one remains Volume for the electronic signal processing unit 65 and the corresponding Battery 70 received.

FIGS. 9 to 11 show examples of possible implementation variants of the electronic signal processing of a hearing aid using the described Converter 15 shown. Basically, the hearing aid includes the microphone 60 which electronic unit 65, which processes and amplifies the microphone signal, the battery 70 to energize the entire hearing aid, an external, wireless or wired unit 67, with the system-related and patient-specific (Adjustment) parameters in the hearing aid changed analog or digital and long-term stable can be stored, as well as the described hearing aid converter 15. Different is the arrangement of the electronic in Figures 9, 10 and 11 Converter driver 66. As described, this unit 66 is an adaptive electronic Interface between the actual hearing aid electronics 65 and the electromechanical Converter drive unit 19 is provided in converter 15.

9, the converter driver 66 is part of the signal processing electronics 65 of the hearing aid. For example, it is in an electronic circuit Integrated chip level.

In the embodiment according to FIG. 10, the driver unit 66 is neither within the signal processing electronics 65 of the hearing aid still in the converter 15, but it is connected between these two units. This implementation variant can mean that the driver electronics 66 is implemented and integrated as a separate chip and together with the signal processing hearing aid electronics 65 according to the applied microelectronic construction technology within the hearing aid is housed. Another implementation variant according to FIG. 10 can consist in that the converter driver circuit 66 is outside the behind-the-ear or in-the-ear hearing aid 10 or 11 and the converter 15 is positioned and for service reasons the two modules hearing aid and transducer via suitable mechanical / electrical Connector is connected. This variant comes for example for the hearing aid arrangement corresponding to FIG. 8.

11 is the implementation of the converter driver 66 within the housing 14 of the Converter 15 shown. This corresponds to the schematic representation of the principle Converter structure according to FIG. 1.

Basically, the electronic converter driver 66 contains all the necessary electronic ones and mechanical components that are required to meet the current application a behind-the-ear or in-the-ear hearing aid depending on the requirement selected electromechanical drive principle of the converter 15 to satisfy. These can be other audio amplifiers, DC / DC converters of all kinds electronic realizations (among other things, known switch-capacitor converter, inductor-based switching regulators etc.), impedance converters, level limiting Elements and other components that, for example, electromagnetic compatibility serve. In particular, an integrating component can be in the driver unit 66 to be included, for example, a piezoelectric transducer 15 according to FIG digital, pulse width modulated signal processing output stage without a D / A converter to be able to connect fully digital hearing aids.

Claims (43)

Electroacoustic transducer for hearing aids, characterized in that in one Hermetically gas-tight housing (14) on all sides, one wall of which can be bent Membrane (17), an electromechanical converter drive unit (19) is housed, and that the converter drive unit with the housing membrane is coupled such that mechanical vibrations of the converter drive unit on the output side mechanically coupled directly from the inside to the housing membrane are and thereby the membrane is excited to bending vibrations, the one Cause sound radiation outside the converter housing. Converter according to claim 1, characterized in that the in the Transducer housing (14) housed electromechanical transducer drive unit (19) on the electromagnetic, electrodynamic, dielectric, piezoelectric or magnetostrictive transducer principle. Converter according to claim 1 or 2, characterized in that the Transducer housing (14) is cylindrical, in particular circular cylindrical. Converter according to one of the preceding claims, characterized in that the sound-emitting transducer membrane (17) is circular. Converter according to one of the preceding claims, characterized in that the converter housing (14) has a housing part (13) which is open on one side and whose open side of the transducer membrane (17) is hermetically sealed. Converter according to one of the preceding claims, characterized in that the housing part (13) is metallic. Converter according to one of the preceding claims, characterized in that the transducer membrane (17) is made of metal. Converter according to claims 6 and 7, characterized in that the housing part (13) and / or the transducer membrane (17) from a non-corrosive, rustproof Metal, especially stainless steel, are made. Converter according to claims 6 and 7, characterized in that the housing part (13) and / or the transducer membrane (17) from a non-corrosive, rustproof and particularly body-compatible metal, in particular titanium, platinum, niobium, or tantalum their alloys are made. Converter according to one of the preceding claims, characterized in that the housing part (13) with a hermetically gas-tight electrical housing bushing (16) is provided. Converter according to claims 6 and 8, characterized in that the Housing bushing (16) is at least one pole and the ground potential on the Housing part (13) is. Converter according to claim 10 or 11, characterized in that the Housing bushing (16) on gas-tight soldered metal-ceramic connections based. Converter according to claim 12, characterized in that the housing bushing (16) an aluminum oxide ceramic as an insulator and an electrical one Feedthrough conductor has at least one platinum-iridium wire. Converter according to one of claims 7 to 13, characterized in that as Electromechanical converter drive unit (19), preferably a circular one trained piezoelectric ceramic disk is provided on the inside the transducer membrane (17) is applied as an electromechanically active element and together with the transducer membrane an electromechanically active one Heteromorphic composite element. Transducer according to claim 14, characterized in that the piezoelectric Ceramic disc (19) consists of lead zirconate titanate. Converter according to claim 14 or 15, characterized in that the thickness of the Transducer membrane (17) and the thickness of the piezoelectric ceramic disc (19) are approximately the same size and are in the range of 0.025 mm to 0.15 mm. Converter according to one of claims 14 to 16, characterized in that the Transducer membrane (17) and the piezoelectric ceramic disc (19) approximately the have the same modulus of elasticity. Converter according to one of claims 14 to 17, characterized in that both the transducer membrane (17) and the housing part (13) are electrically conductive that the piezoelectric ceramic disc (19) with the transducer membrane through a electrically conductive adhesive is electrically connected, and that Housing part one of at least two electrical converter connections (16a) forms. Converter according to one of claims 14 to 18, characterized in that the Radius of the transducer membrane (17) by a factor of 1.2 to 2.0, preferably one Factor of about 1.4, larger than the radius of the piezoelectric ceramic disk (19). Converter according to one of claims 1 to 13, characterized in that the Electromechanical converter drive unit (19) as an electromagnet arrangement (21, 22), which is a component fixed with respect to the converter housing (14) (22) and an oscillatable component (21) which is connected to the inside of the Transducer membrane (17) is coupled. Transducer according to claim 20, characterized in that the oscillatable Component (21) is attached substantially in the center of the transducer membrane (17). Converter according to claim 20 or 21, characterized in that with the Inside of the transducer membrane (17) is a component that forms the oscillatable component Permanent magnet (21) is connected and that an electromagnetic coil (22) in the converter housing (14) is firmly attached to the permanent magnet in To vibrate. Transducer according to claim 22, characterized in that the permanent magnet (21) is designed as a magnetic pin and the coil (22) is a ring coil with a Central opening (22a), in which the magnetic pin is immersed. Converter according to one of the preceding claims, characterized in that by choosing the mechanical properties of the transducer membrane (17) and the Converter drive unit (19) the oscillating system comprising these components is tuned so that the first mechanical resonance frequency of the whole Transducer (15) is spectrally at the upper end of the transmission range. Transducer according to claim 24, characterized in that the first mechanical Resonance frequency of the entire transducer (15) in the range from 4 to 12 kHz, in particular around 10 kHz. Converter according to one of the preceding claims, characterized in that a converter driver (66) is additionally accommodated in the converter housing (14). Converter according to one of the preceding claims, characterized in that the converter drive unit (19) is electrically controlled so that the deflection the transducer membrane (17) up to the first resonance frequency independent of frequency is embossed. Hearing aid, which as an output-side sound transducer is an electro-acoustic transducer (15) according to one of the preceding claims. Hearing aid according to claim 28, characterized in that it is used as a behind-the-ear device (10), In-the-ear device (11) or glasses device is formed. Hearing aid according to claim 28 or 29, characterized in that regardless of Hearing aid type of the electroacoustic transducer (15) together with a microphone (60), a power supply source (70), signal processing and amplifying Elements (65, 66) and any other for a hearing aid function necessary components is housed in a hearing aid housing (12). Hearing aid according to claim 28 or 29, characterized in that regardless of Hearing aid type of the electroacoustic transducer (15) in a separate housing housed and with an at least two-pole electrical line (40) the hearing aid (10, 11) is connected, which is a microphone (60), a Power supply source (70), signal processing and amplifying elements (65, 66) and any other components necessary for a hearing aid function contains. Hearing aid according to claim 31, characterized in that the separate housing, which contains the electroacoustic transducer (15), integrated in an earmold (25) is. Hearing aid according to claim 32, characterized in that the electro-acoustic transducer (15) containing earmold (25) with a behind-the-ear hearing aid (10) via a flexibly deformable coupling element (45) is mechanically connected, the individual adaptation to the anatomy of the Permitted outer ear and contains the electrical lead (40) to the converter. Hearing aid according to one of claims 28 to 33, characterized in that at Installation of the electroacoustic transducer (15) in an earmold (25) or directly in an in-the-ear device (11) the transducer housing (14) is arranged so that the Transducer membrane (17) at least approximately flush with the area of the Earpiece or in-the-ear device housing that closes the Ear canal facing. Hearing aid according to one of claims 28 to 33, characterized by a electronic converter driver (66), which the signal processing electronics of the Hearing aid (10, 11) to the selected electromechanical principle of converter-internal converter drive unit (19) the respective objectives of Adapts output level and frequency range accordingly. Hearing aid according to claim 35, characterized in that the hearing aid (10, 11) is fully digital and has a pulse width modulated output stage, and that the converter driver (66) for connecting the pulse width modulated Output stage has an integrating function. Hearing aid according to claim 35 or 36, characterized in that the Converter driver (66) in the signal processing electronics (65) of the hearing aid (10, 11) is also integrated. Hearing aid according to claim 35 or 36, characterized in that the Converter driver (66) is a separate electronic module. Hearing aid according to claim 38, characterized in that the driver module (66) is housed in the hearing aid housing (12). Hearing aid according to claim 38, characterized in that the driver module (66) is arranged between the hearing aid and the electroacoustic transducer (15). Hearing aid according to claim 38, characterized in that the driver module (66) in the converter housing (14) is housed. Hearing aid according to claim 40 or 41, characterized in that for electrical Supply of the driver module (66) from the hearing aid (10, 11) according to the principle the phantom power is the electrical connection between the hearing aid electronics (65) and the driver module is bipolar and contains a signal AC voltage is superimposed on a DC voltage that the driver module provided. Hearing aid according to one of claims 40 to 42, characterized in that the Driver module (66) via detachable mechanical or electrical plug connections connected to the hearing aid (10, 11) or the electroacoustic transducer (15) is.

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