EP0821543A2 - Membrane as outer surface of a hearing aid which is individualised by moulding a body - Google Patents

Abstract

The membrane (14), for a hearing aid, has zones of different thicknesses. The membrane is of a thermoplastic elastomer or a high-stretch silicon, produced by injection moulding, with the thinnest zone having a thickness of 0.1-0.3 mm.

Description

The invention is in the field of hearing aids and relates to a membrane according to the preamble of the independent claim. The membrane forms the outer surface of a hearing aid, which has the shape of an irregular Has truncated cone or cylinder and essentially serves for flexible delimitation of a casting cavity in which for the adjustment a body is cast on an individual ear canal.

Various hearing aids have been described which are made by casting of a body in an individual ear canal or in a model of a such an ear canal can be individualized for a specific person. If casting such a body is essentially the last manufacturing step and is simple, that is to say can be carried out without complicated aids, can such a hearing aid in a general, that is, not yet delivered an individual ear canal adapted condition to hearing aids will. The hearing advisor can then connect the device to the ear canal Adjusting the person means pouring the body, and actually the finished device hand over to this person after a single session.

Such a simple individualization of a hearing aid primarily requires that as far as possible all components serving the hearing function (microphone and / or receiving coil, amplifier chip and loudspeaker) in general Hearing aid are already installed and that this general hearing aid one Has casting cavity in which the individual body are poured can be such that the body cannot be reworked after casting got to.

An adaptation to an individual ear canal is important for partially in the Hearing aids worn in the ear canal ("in-the-canal devices" or ITC devices) and especially for hearing aids worn completely in the ear canal ("Completely-In-the-Canal-Devices" or CIC devices). Such devices have essentially the shape of an irregular truncated cone or cylinder with a the inner end face directed towards the inside of the ear, one towards the outside directed, outer end face and a lateral surface, only the Lateral surface comes into contact with the ear canal and therefore only this Shell surface to be adapted to the shape of an individual ear canal got to.

Hearing aids that meet the requirements of easy customization, are described, for example, in publication EP-629101 and in a Parallel application for this application (Sweizer application no. 1859/96). The hearing aids described in both cases show in their general condition with a front plate defining the outer face a battery opening and other at least partially load-bearing elements, through which in particular the speaker in a relative to the front panel defined position, that is, at least at a fixed distance from it, is held such that these additional elements and / or the output side of the speaker essentially the inner end face of the device represent. The outer surface of the devices is essentially tubular, stretchable membrane around the outer face (Front panel) and around the inner face (formed by loudspeakers and / or other elements) is attached such that they are together with the front panel and speakers and / or other elements in the area of the inner Front forms a dense casting cavity, which through a pouring opening can be poured out with a casting compound in the area of the front panel. The General device is used for casting the body in the ear canal of the potential Carrier or positioned in a corresponding model. The membrane When the body is poured, it fits tightly against the ear canal wall, so that the cast body of the device so individualized exactly to the Ear canal is adapted and carries the membrane on its lateral surface.

• Die Membran muss derart dehnbar sein, dass sie sich beim Giessen des Körpers faltenlos und sehr eng an die Gehörgangwand (oder an die Wand eines entsprechenden Modells) anlegt.
• Die Membran muss als Kontaktelement des Hörgerätes mit der Haut des Gehörganges für einen dauernden, engen Hautkontakt geeignet, das heisst in einem hohen Grad hautkompatibel sein.
• Die Membran muss eine genügende mechanische Festigkeit aufweisen, damit das generelle Gerät (mit leerem Giesshohlraum, d.h. ohne Körper) problemlos hergestellt und sicher handhabbar ist.
• Die Membran muss einfach an anderen Bestandteilen des Hörgerätes befestigbar sein.

A wide variety of requirements must be placed on a membrane forming the outer surface of a hearing aid:

• The membrane must be stretchable so that when the body is poured, it lies tightly against the ear canal wall (or the wall of a corresponding model).
• As a contact element of the hearing aid with the skin of the ear canal, the membrane must be suitable for permanent, close skin contact, that is to say it must be skin-compatible to a high degree.
• The membrane must have sufficient mechanical strength so that the general device (with an empty casting cavity, ie without a body) can be manufactured without any problems and can be handled safely.
• The membrane must simply be attachable to other components of the hearing aid.

It also shows that membranes that are so porous that they are for air permeable, but impermeable to a casting compound for casting the body are, not only when casting the molded body but also with respect Comfort has advantages.

For fastening the membrane to the front panel and in the area of the inner End face on the loudspeaker and / or on supporting elements of the device are clamping elements (fixing rings or with corresponding openings provided closing elements, which extend over the entire end faces) have been proposed or direct gluing or welding of the membrane with the front panel and with load-bearing elements in the area of the inner Face. It now turns out that especially for CIC devices that are extremely are small, the attachment of the membranes described with the described Fasteners and fastening methods a rather difficult one is a complex and time-consuming work step. The reason for this is in the sensitivity of the very thin (approx. 0.2 mm) membrane and in the Smallness of the separate fasteners.

It is the object of the invention to provide a membrane for an ITC hearing aid or to create a CIC hearing aid that is easier on other parts of the device can be attached as corresponding membranes according to the prior art Technology.

This object is achieved by the membrane as it is by the claims is defined.

The membrane according to the invention takes advantage of the fact that the Force that is necessary to stretch a material or the elastic force, that the stretched material can exert, not just the material properties but also depends on the thickness (wall thickness) of the material is. The membrane according to the invention accordingly has areas of different Wall thickness as areas for different functions. Areas with higher wall thickness (higher elastic force) serve in particular as elastic fasteners; Areas with smaller wall thickness (smaller Resistance to stretching) serve in particular as an elastic boundary of the casting cavity. In addition, other areas with other Wall thicknesses can be provided for other functions.

In other words, this means that in the membrane according to the invention Fasteners are directly integrated, which essentially gives two advantages adult: firstly, the fastening position of the membrane is precisely defined and regardless of the individual course of the fastening process, and secondly there is no further part to be handled separately (clamping ring). This two advantages lead to a considerable simplification of the fastening process and to a more uniform result.

The membrane according to the invention is advantageously made of, for example a silicone plastic manufactured in an injection molding process, the Fasteners cast as areas with a larger wall thickness will.

Examples of advantageous materials for the membrane according to the invention are thermoplastic elastomers or highly elastic silicone plastics (e.g. two-component silicones) with an elasticity of over 500% and a Shore A hardness of less than 40.

Figuren 1 und 2

schematische Schnitte (parallel zur Achse des Gerätes) durch ein beispielhaftes Hörgerät mit einer erfindungsgemässen Membran in generellem Zustand (Figur 1), das heisst vor dem Giessen des Körpers, und in individualisiertem Zustand, das heisst nach dem Giessen des Körpers;

Figur 3

eine beispielhafte Ausführungsform der erfindungsgemässen Membran als Schnitt parallel zur Achse;

Figur 4

eine beispielhafte Befestigung einer erfindungsgemässen Membran an einer Frontplatte oder einem tragenden Element im Bereiche der inneren Stirnfläche (im Schnitt parallel zur Achse);

Figur 5

eine beispielhafte Befestigung einer erfindungsgemässen Membran am Lautsprecher eines Hörgerätes (im Schnitt parallel zur Achse);

Figur 6

beispielhafte Befestigungsmittel einer erfindungsgemässen Membran am Lautsprecher eines Hörgerätes, die auch einen Ausgang für einen Ventkanal aufweisen (quer zur Achse geschnitten, Schnittlinie VI-VI in Figur 3);

Figur 7

weitere Befestigungsmittel wie Figur 6.

Exemplary embodiments of the membrane according to the invention are described in detail with reference to the following figures. Show:

Figures 1 and 2

schematic sections (parallel to the axis of the device) through an exemplary hearing aid with a membrane according to the invention in a general state (FIG. 1), that is to say before the body is cast, and in an individualized state, that is to say after the body has been cast;

Figure 3

an exemplary embodiment of the membrane according to the invention as a section parallel to the axis;

Figure 4

an exemplary attachment of a membrane according to the invention on a front plate or a supporting element in the region of the inner end face (parallel to the axis in section);

Figure 5

an exemplary attachment of a membrane according to the invention to the loudspeaker of a hearing aid (parallel to the axis in section);

Figure 6

exemplary fastening means of a membrane according to the invention on the loudspeaker of a hearing aid, which also have an outlet for a vent channel (cut transversely to the axis, section line VI-VI in FIG. 3);

Figure 7

further fastening means as in FIG. 6.

FIGS. 1 and 2 show, as schematic sections parallel to the axis, an example of a hearing aid which is individualized by casting a body in an auditory canal or an auditory canal model, that is to say is adapted to an individual auditory canal. A membrane forming the outer surface of the device is provided for casting the body. The hearing aid is shown in its general state (FIG. 1), that is to say before the body is poured, and in its individualized state (FIG. 2), that is to say after the body has been poured. The hearing aid shown is a CIC device. The device itself is the subject of a parallel application to the present application (Swiss application No. 1859/96) and is therefore not described in detail here. The membrane according to the invention can be used not only on a hearing aid, as shown in FIGS. 1 and 2, but also on other hearing aids that are individualized by pouring out a casting cavity, for example also on a hearing aid, as described in the publication EP -629101.

The hearing aid shown has, for example, elements serving as the hearing function a microphone 10, an amplifier chip 11 and a loudspeaker 12 and a front panel 13 with a battie opening or with a Battery compartment, the front panel 13 essentially the outer end face and the output side of the speaker 12 is essentially the inside Show the face of the device.

FIG. 1 shows the device in its general state. A membrane 14 extends essentially in the form of a tube from the outer to the inner end face and represents the outer surface of the device. The membrane delimits a casting cavity 15 which, for example, includes a pouring opening in a casting template 16 a casting compound is pourable. The casting template 16 is positioned in the battery opening of the front plate 13 and serves primarily to keep a battery compartment free between the body to be cast and the front plate. Furthermore, the general hearing aid has a provisional support element 18 which protrudes from the device on the outer and on the inner end face and is removed therefrom after the body has been cast.

It turns out that the device is not necessarily in its general condition needs a supporting element that extends axially through the device. It it is also sufficient, through a flexible, the distance between the inner and the outer front limiting element, which also after casting the Body can be removed.

Figure 2 shows the same device as Figure 1 but in its individualized state, that is, after casting the body. The individualized device differs from the general one by the body 20, by the lack of the provisional support element (or the length-limiting element), the removal of which creates a vent channel 21 through the device, and by the battery 19 replacing the casting template and the battery cover 22 The membrane 14 essentially still forms the outer surface of the device and lies closely against the body 20.

FIG. 3 shows an exemplary embodiment of the membrane 14 according to the invention in a section parallel to the axis. The membrane is essentially tubular and has an outer opening 30 and an inner opening 31. Outer fastening means 32 and inner fastening means 33 are arranged around the two openings, which essentially have the form of thickenings, ie areas in which the wall thickness is greater than in a central area 34 of the membrane. In the example shown, the outer fastening means 32 are designed as an elastic ring which, for fastening the membrane to a front plate, is positioned, for example, in a corresponding groove in this front plate, in which it is advantageously somewhat tensioned. The inner fastening means 33 have the shape of an internally stepped hose, the inner opening of which is matched to a loudspeaker, in such a way that a loudspeaker positioned in this opening elastically stretches the hose and is thereby held in place.

The central region 34 of the membrane is stretched when the body is poured. This region 34 can be used to even out this expansion Have patterns of other areas with increased wall thickness, but the wall thickness in these areas is significantly smaller than in the areas of the fasteners. Such a pattern exists, for example from inwardly directed, linear thickenings 35, which extend around the circumference of the tubular membrane.

Such a pattern of thickening can cause unfavorable effects, caused by weak points in the membrane can be prevented. If a membrane has a weak point without such thickening, it becomes only in the initial stage of casting due to the resulting pressure stretched at this point, which further weakened this point and still is stretched further. Very undesirable humps can form in this way. Since the thickenings of the pattern mentioned have a higher wall thickness, a corresponding vulnerability has a significantly smaller impact on their elasticity, so that a pattern of such thickenings mentioned undesirable effects prevented.

If thickening, as in Figure 3 as in the form of rings around ribs extending the inner periphery of the membrane are shown extend on the inside of the membrane in the axial direction and accordingly are dimensioned, they can in addition to the equalizing the expansion of the membrane Effect as a further function also the length limitation of the hearing aid. This function is very important because it is essential To prevent the hearing aid from turning during the pouring of the Body extended by a corresponding longitudinal expansion of the membrane and thereby hits the eardrum. If the length limit is absolute can not only be reliably taken over by the membrane as mentioned above on the provisional support element but also on a axially running length-limiting element can be dispensed with.

• zentraler Bereich: 0,1 bis 0,3 mm
• äussere Befestigungsmittel: ≥ 0,5 mm
• innere Befestigungsmittel: ≥ 0,5 mm
• Muster von Verdickungen im zentralen Bereich: 0,2 bis 0,5 mm (ca. um Faktor 2 grösser als übrige Wanddicke des zentralen Bereiches).

Typical wall thicknesses for a tubular membrane, as shown in FIG. 3, are for example:

• central area: 0.1 to 0.3 mm
• external fasteners: ≥ 0.5 mm
• inner fasteners: ≥ 0.5 mm
• Pattern of thickening in the central area: 0.2 to 0.5 mm (approx. 2 times larger than the remaining wall thickness of the central area).

Further embodiments of the membrane according to the invention, which from the in The embodiment shown in Figure 3 can be derived, for example fasteners only in the area of the outer opening while the area of the inner opening, for example by gluing or welding is attached to other elements of the hearing aid. It can in Areas of the inner opening can also be provided with fastening means which like the outer fasteners shown, a fastening ring represent the corresponding internal support elements of the device in a groove is positioned. The outer and / or inner fasteners can also instead of by positive locking (ring in groove) without or with elastic expansion by material bonding (gluing or welding) to others, accordingly shaped components of the hearing aid to be attached.

FIG. 4 shows the outer fastening means of the membrane according to FIG. 3 on a larger scale. Parts of the front plate 13, the body 20 and the membrane 14, in particular the outer fastening means 32 and the central region 34, are visible. It can be seen from the figure that a very continuous shape can be produced by appropriately shaping the thickening between membrane 14 and front plate 13.

Between outer fastening means 32 in the form of an edge thickening and the thin, central area of the membrane is a continuous transition area 36 provided. This increases the stability of the membrane this transition area and increases the strength of a connection between Front panel 13 and body 20 when cast from one material becomes stable during casting with the membrane material Connection comes in, for example by anchoring the casting compound in Pores of the membrane or by an adhesive / chemical bond between Casting compound and membrane.

FIG. 5 shows a further embodiment of inner fastening means 33 integrated into a membrane 14. The loudspeaker 12 and parts of the membrane 14, in particular the inner fastening means 33 and the central area 34, are visible. Furthermore, a perforated protective cap 37 is shown, which by means of a snap lock sits positively on the outermost edge of the fastening means 32, which edge is designed as a form-locking means 39. The protective cap 37 has the function of protecting the loudspeaker output from contamination by cerumen. The actual fastening means 32 are in the form of an elastic tube, which advantageously has a step 38. The hose and the step are dimensioned such that the loudspeaker can be inserted down to the step, the hose being stretched in such a way that the loudspeaker is held in this position by the elastic force of the stretched hose.

As already mentioned above, the membrane according to the invention is advantageously manufactured in an injection molding process. In such a It is also possible to restrict different materials to one another to pour, so that between the different materials very stable Flow seams arise. It is now possible, especially in the range of internal fastening means, as shown in Figure 5, for example to use a slightly harder material for the form-locking means 39 than for the rest of the membrane.

• Membran und Befestigungsmittel: thermoplastische Elastomere oder hochdehnfähige Silikone
• Formschlussmittel: Plyamid

An exemplary pair of materials for the production of the fastening means 33 and the form-locking means 39 is the following:

• Membrane and fasteners: thermoplastic elastomers or highly stretchable silicones
• Positive locking agent: plyamide

FIGS. 6 and 7 also show sections transverse to the axis (section line VI-VI in FIG. 3) through exemplary embodiments of internal fastening means as are necessary for the hearing aid according to FIGS. 1 and 2. In its general state, the hearing aid according to FIGS. 1 and 2 has a preliminary support element (18 in FIG. 1) which projects beyond both end faces or a corresponding, flexible length-limiting means, both of which are pulled out of the device after the body has been cast. Supporting element or length-limiting element need openings on both end faces, which openings represent the openings of the vent channel in the individualized area. The fastening means according to FIGS. 6 and 7 also have the inner opening of the vent channel in addition to their features which serve the function of fastening the membrane to the loudspeaker (inner end face).

In both Figures 6 and 7 show the tubular fastening means 33, which according to their double function has a first opening 40 for the speaker and a second opening 41 for the vent channel and for the have provisional support element or length restriction element. In the Figure 6, the second opening 41 is provided as a separate opening in the Figure 7 as bulge of the first opening 40. In both cases, in the second opening 41, a sleeve can be provided, the sleeve in the case is advantageously additionally attached to the loudspeaker according to FIG. 7, for example by gluing.

Claims (15)

Essentially tubular, stretchable membrane (14) with an outer opening (30) and an inner opening (31) for a hearing aid, which has the shape of an irregular truncated cone or cylinder with an outer end face, an inner end face and a lateral surface and through Casting of a body (20) can be individualized, the membrane (14) being attached to further components of the device (13, 12) around the two end faces and forming the outer surface of the device, characterized in that the membrane (14) has areas of different wall thickness having. Membrane according to claim 1, characterized in that it has fastening means (32) in the form of an annular thickening extending around the opening (30, 31) for fastening to components of the hearing aid at least in the region of its outer opening (30, 31). Membrane according to one of claims 1 or 2, characterized in that it has fastening means (33) in the form of a tubular thickening in the region of its inner opening (31) for fastening to a loudspeaker (12) of the hearing aid. Membrane according to claim 3, characterized in that it has a step (38) for positioning the loudspeaker (12) on the inside of the tubular thickening. Membrane according to claim 3 or 4, characterized in that the outermost region of the tubular thickening for attaching a protective cap (37) is designed as a positive locking means (39). Membrane according to claim 5, characterized in that the positive locking means (39) consists of a less stretchable material than the rest of the membrane. Membrane according to one of claims 3 to 6, characterized in that the tubular thickening in addition to a first opening (40) for the loudspeaker (12) has a second opening (41) for a vent channel. Membrane according to claim 7, characterized in that the second opening (41) is a bulge of the first opening (41). Membrane according to one of claims 1 to 8, characterized in that it has a pattern of thickenings in a central region. Membrane according to claim 9, characterized in that the thickenings are linear and extend around the inner periphery of the membrane. Membrane according to claim 9, characterized in that the thickenings extend in the axial direction and serve to limit the length of the membrane in the axial direction. Membrane according to one of claims 9 to 11, characterized in that the linear thickenings have a wall thickness which is approximately twice as large as the wall thickness of the membrane between the thickenings. Membrane according to one of claims 1 to 12, characterized in that it consists of a thermoplastic elastomer or of a highly stretchable silicone plastic. Membrane according to claim 13, characterized in that it has a wall thickness of 0.1 to 0.3 mm at its thinnest points. Membrane according to claim 13 or 14, characterized in that it is produced by an injection molding process from one or more materials.

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