Abstract
A transducer protection system for the protection of at least one transducer opening in a housing of a hearing device, including a support and a plurality of fibers each fixed at one end to the support and free to move on the other end.
Claims
1. A transducer protection system (10;100) for the protection of at least one transducer opening (108) in a housing of a hearing device (110), comprising a supporting means (12;102) and a plurality of fibers (14;104) each fixed at one end to the supporting means (12;102) and free to move on the other end.
2. The transducer protection (10) system according to claim 1, wherein the supporting means comprises a carrier ring (12), wherein the fibers (14) are fixed along the inner race thereof, circumferentially, such to be directed to the center of the carrier ring (12).
3. The transducer protection system (10) according to claim 2, wherein the carrier ring (12) is adapted to be fixedly inserted by its outer race into the transducer opening (108) of the hearing device (110).
4. The transducer protection system (10) according to claim 2, wherein the fibers (14) are fixed to the inner race such to originate across at least a portion along the axis of the carrier ring (12).
5. The transducer protection system (10) according to of claims 2, wherein the length of the fibers (14) is chosen such to exceed the radius of the carrier ring (12).
6. The transducer protection system (10) according to claim 2, wherein the fibers (14) are arranged such that distal end portions thereof overlap each other in at least a center portion (C) of the carrier ring (12).
7. The transducer protection system (100) according to claim 1, wherein the supporting means comprises a central shaft (102), wherein the fibers (104) are fixed to the central shaft (102) such to protrude radially thereof, and wherein the supporting means is adapted to be inserted into the transducer opening (108) such to be aligned to the center axis of the transducer opening (108).
8. The transducer protection system (100) according to claim 7, wherein the fibers (104) are fixed to the central shaft (102) such to originate across at least a portion of the axis thereof.
9. The transducer protection system (100) according to claim 8, wherein the distribution density of the fibers (104) along the axis of the central shaft (102) is decreasing towards the distal end thereof.
10. The transducer protection system (100) according to claim 7, wherein the length of the fibers (104) is chosen such to exceed the radius of the transducer opening (108).
11. The transducer protection system (100) according to claim 7, wherein the supporting means further comprises a carrier structure (106) supporting the central shaft (102), adapted to couple the central shaft (102) to at least a portion of the hearing device (110).
12. The transducer protection system (100) according to claim 11, wherein the carrier structure (106) is adapted to abut on at least a portion of the outer periphery of the transducer opening (108).
13. The transducer protection system (100) according to claim 7, wherein the distal ends of the fibers (104) are adapted to get stuck by the transducer opening wall (116) such to fixedly mount the supporting means to the housing of the hearing device (110).
14. The transducer protection system (10;100) according to claim 1, wherein the fibers (14;104) are monofilament fibers.
15. The transducer protection system (10;100) according to claim 1, further comprising a hydrophobic coating applied to the fibers (14;104), preferably a hydrophobic polymer coating.
16. The transducer protection system (10;100) according to claim 1, wherein the cross section of the fibers (14;104) varies along the main axis thereof.
17. A hearing device (110) comprising a housing and at least one transducer (118) provided into the housing, wherein the housing comprises at least one transducer opening (108), each exposing the at least one transducer (118) to the outside, further comprising at least one transducer protection system (10;100) according to one of the preceding claims mounted to the at least one transducer opening (108).
18. Usage of a transducer protection system (10;100) according to claim 1 for the protection of at least one transducer opening (108) in a housing of a hearing device (110) against the entrance of at least one of cerumen and debris particles (22).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention is further described with reference to the accompanying drawing jointly illustrating various exemplary embodiments which are to be considered in connection with the following detailed description. What is shown in the Figures is the following:
[0029] FIGS. 1a,b are schematically views of a transducer protection system according to a first embodiment in a cross sectional view and in a top view;
[0030] FIGS. 2a-c are schematically views of different fiber geometries;
[0031] FIGS. 3a,b are schematically views of a cleaning process for the transducer protection system according to the first embodiment;
[0032] FIGS. 4a-c are schematically views of a transducer protection system according to a second embodiment in a cross sectional view and in a top view;
[0033] FIG. 5 is a schematically cross sectional view of the transducer protection system according to the second embodiment inserted into a transducer opening of a hearing device in a first example;
[0034] FIG. 6 is a schematically cross sectional view of the transducer protection system according to the second embodiment inserted into a transducer opening of a hearing device in a second example;
[0035] FIG. 7 is an enlarged view of the transducer protection system according to the second embodiment inserted into the transducer opening exemplifying the fibers getting stuck; and
[0036] FIG. 8 shows a hearing device provided with a transducer protection system according to the second embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0037] FIGS. 1a,b are schematically views of a transducer protection system 10 according to a first embodiment in a cross sectional view along the axis thereof and in a top view. The transducer protection system 10 comprises a supporting means 12 and a plurality of fibers 14, each fixed at one end to the supporting means 12 and free to move on the other end. In this embodiment, the supporting means 12 comprises an annular means. The plurality of fibers 14 are fixed to the annular supporting means 12 such to protrude radially towards the center of the annular supporting means 12. These fibers 14 can be made shorter (not shown) or longer than the radius of the annular supporting means 12. In case of each or at least a part of the fibers 14 are longer than the radius of the annular supporting means 12, these fibers 14 will cross each other in the center C region of the annular supporting means 12. Thus, the center C region has the highest density of fibers 14.
[0038] The fibers 14 can be made straight or curved depending on the respective design of the transducer protection system 10. Further, the density of the fibers 14 can be varied depending on the respective application. While a high density of fibers 14 enhances the ability to protect against entrance of cerumen or debris particles, the respective placement of the fibers 14 has to be selected in view of the required acoustic transparency of the transducer protection system 10. This tradeoff between protection mechanism and acoustic transparency can be selected depending on the desired application. The shown assembly of the fibers 14 serves reliably as barrier against entrance of cerumen and/or debris particles.
[0039] FIGS. 2a-c are schematically views exemplifying different geometries of respective fibers 14′-14′″. In particular, examples of different fiber geometries that could be used in the present invention are shown. The geometry of each single fiber can be varied or fibers of different geometries can be combined for an optimal adaptation to a given task. The fibers 14′-14′″ are shown schematically having a fixed end 16′-16′″ and a free end 18′-18′″. The cross section of each fiber can vary along its main axis in adaptation to different tasks.
[0040] In the case shown in FIG. 2a, the fiber 14′ is irregular in cross section, leading to a high specific surface area. In combination with a hydrophobic coating, this fiber 14′ geometry has a high degree of hydrophobicity and oleophobicity. In particular, in order to further improve resistance against water and oily cerumen, the hydrophobic coating can be applied to the fibers. As to the coating, for example by a CVD (Chemical Vapor Deposition) coating technology, a thin (<100 nm) hydrophobic polymer coating is deposited conformably onto the substrate of the fibers. As the coating is applied from the vapor phase, highly porous structures such as the proposed fiber assembles can be conformably coated easily.
[0041] In the example shown in FIG. 2b, the fiber 14″ is cylindrical and straight in shape, serving to achieve a transducer protection system having high degree of prediction and control of mechanical properties.
[0042] The fiber 14′″ exemplified in FIG. 2c becomes thinner towards the free end 18′″ thereof. Advantageously, due to this configuration, if the fiber density is high, the amount of fiber material in the center of the transducer protection system can be reduced.
[0043] FIGS. 3a,b depict a cleaning process for the transducer protection system 10 according to the first embodiment. The transducer protection system 10 according to the first embodiment can be cleaned very easily from cerumen and/or debris particles 20. As can be best seen in FIG. 3a, cerumen and/or debris particles 20 get entrapped in the fibers 14 of the transducer protection system 10 like in cilia in natural orifice. Advantageously, due to the fact that the individual fibers 14 can be bent, a cleaning tool 22 such as a brush is allowed to be inserted into the opening and retrieved without damaging the transducer protection system 10. If cleaning becomes necessary, the cleaning tool 22 having a thin cylindrical body 24 and a cleaning tip 26 can be axially introduced into the opening of the transducer protection system 10.
[0044] In doing so, the fibers 14 will bend down, allowing the cleaning tool 22 to engage the cerumen and/or further debris particles 20. The cleaning tip 26 can be realized by a brush itself having small monofilament fibers as known for dental applications, for example intra dental brushes. In another example, the cleaning tip 26 can be realized by a fiber assembly of non-woven fibers such as a small Q-tip or a microbrush.
[0045] FIGS. 4a-c show a transducer protection system 100 according to a second embodiment in a side view and in a top view. As best shown in FIG. 4a, the transducer protection system 100 comprises a central shaft 102 elongated such to fixedly support a plurality of fibers 104. The fibers 104 are fixed along and around the central shaft 102 such to protrude radially thereof. Therefore, due to radial pressure of the fibers 104 the central shaft 102 can be inserted into a transducer opening of a hearing device (not shown) such to be aligned to the center axis thereof.
[0046] A carrier structure 106 is provided for supporting the central shaft 102 in order to couple the central shaft 102 to at least a portion of a hearing device (not shown). The central shaft 102 is supported by the carrier structure 106 in the center thereof such that the axis of the central shaft 102 and the plane of the carrier structure 106 are perpendicular to each other.
[0047] As best shown in the top views as depicted in FIGS. 4b and 4c, the carrier structure 106 protrudes radially further than the fibers 104 in order to prohibit the transducer protection system 100 to be pushed into the transducer opening (not shown) too deep. Further, as best shown in FIGS. 4b and 4c, the carrier structure 106 is formed such to be acoustically transparent. Therefore, in a first alternative, the carrier structure 106 can be realized as a ring with a central strut, as schematically shown in FIG. 4b. As an alternative, the carrier structure 106 can be formed cross-like, as schematically shown in FIG. 4c. The carrier structure 106 can be made from an injection molded thermoplastic part, for example. While not shown, a variety of other designs are possible in order to allow that the transducer protection system 100 is proper supported into a transducer opening.
[0048] Compared to the transducer protection system 10 according to the first embodiment (refer to FIG. 1), in the transducer protection system 100 according to the second embodiment, the fibers 104 are protruding radially from the central shaft 102 which itself is connected to the carrier structure 106. Therefore, the transducer protection system 100 can be placed easily into the sound opening of a hearing device (not shown). As the fibers 104 can be bent and deflected easily upon radial pressure, the transducer protection system 100 can compensate for any geometric tolerances. Therefore, bushings used to be placed into the transducer opening can be omitted. According to the second embodiment, tolerances between the transducer protection system and the transducer opening are rendered irrelevant. Hence, according to the second embodiment, there is no risk that the transducer protection system 100 may fall of the transducer opening and drop into the ear canal of the user. Further, applying a high force in order to insert the transducer protection system into a transducer opening can be omitted.
[0049] The transducer protection system 100 as shown in FIG. 4a comprises a gradient in fiber density (fibers per volume) along the axis of the central shaft 102. Therefore, clogging dynamics of the transducer protection system 100 can be optimized. In other words, the distribution density of the radially protruding fibers 104 can be made varying over the length of the central shaft 102 thus creating a fiber gradient. Depending on the respective application, this gradient can be made increasing or decreasing towards the distal end of the central shaft 102.
[0050] FIG. 5 schematically depicts the transducer protection system 100 inserted into a transducer opening 108 of a hearing device 110. The fibers 104 of the transducer protection system 100 are protruding radially from the central shaft 102 which is fixed to the carrier structure 106 or integrally molded therewith. When the transducer protection system 100 is fixed into the transducer opening 108, the carrier structure 106 becomes to abut against or rather rest on a bushing 112 which is glued into the shell 114 of the hearing device 110. The bushing 112 is connected to the inner race of a wall 116 of the transducer opening 108 which itself connects a transducer (not shown) of the hearing device 110 to the outside.
[0051] FIG. 6 shows the arrangement shown in FIG. 5, wherein a bushing (bushing 112, refer to FIG. 5) is omitted. In the example shown in FIG. 6, the transducer protection system 100 is safely and directly placed into the transducer opening 108. As the plurality of fibers bend upon radial pressure, axial force applied to the wall 116 of the transducer opening 108 during insertion and removal of the transducer protection system 100 is decreased, minimizing the possibility to damage the adhesion bonded interface to the shell 114. The inner race of the wall 116 of the transducer opening 108 can be made of rubber, for example. One major advantage of the exemplary embodiment as shown in FIG. 6 relies on the possibility to maintain the diameter of the transducer opening 108 maximal. Therefore, acoustic transparency can be increased.
[0052] FIG. 7 schematically shows the engagement of the fibers 114 with the wall 116 of the transducer protection system 100 shown in FIG. 6 in an enlarged view. As schematically depicted, the inner race of the wall 116 of the transducer opening 108 is formed such to comprise a rough surface. Optionally or as an alternative, the inner race surface of the wall 116 can be formed sawtooth-like. Therefore, the distal ends of the fibers 114 are allowed to get stuck or rather properly engaged by the wall 116 of the transducer opening 108 such to fixedly mount the central shaft 102 to the wall 116 or rather the housing of the hearing device. Therefore, unintentional removal of the transducer protection system 100 from the transducer opening 108 can be omitted. Increasing the friction between the transducer protection system 100 and the wall 116 results to increased retention forces.
[0053] FIG. 8 is a schematic view of the hearing device 110 equipped with the transducer protection system 100 according to the second embodiment. The hearing device 110 accommodates a transducer 118. Further comprised is a transducer opening 108 exposing the transducer 118 to the outside. Advantageously, the transducer 118 is protected by the transducer protection system 100 against entrance of cerumen and/or debris particles. Further, the fibers of the transducer protection system 100 can be cleaned easily, for example by means of a brush, without damaging the transducer protection system 100 or the hearing device 110 itself.
[0054] Further, the transducer protection system 100 can be exchanged easily, for example in case of a retrofit, in which a user wants to change the transducer protection system 100 because of its acoustic transparency. This acoustic transparency results from the 3-dimensional arrangement of the fibers and the relatively large space between single fibers. Additionally, in case of any disconnected fibers, this will not result in vibrational modes as known from membranes, which could lead to additional distortions. Due to its large specific surface area, the proposed transducer protection system is—in combination with a hydrophobic CVD coating—very resistant against liquids and droplets. As the porosity can be controlled easily by means of adjusting the density of the fibers and the respective geometry of the single fibers, an optimal design for each given diameter or shape of the transducer opening 108 to be protected can be developed.
[0055] Due to its large specific surface area, the transducer protection system 100 according to the present invention is very resistant against oily cerumen. In order to further improve the resistance, a hydrophobic/oleophobic CVD coating can be applied. The geometries of the fibers 114 can be selected such to achieve higher surface area to thus further improve protection against entrance of oily cerumen. In case of liquid cerumen entering the interfibrous space causing single fibers to stick together, the transducer protection system 100 can be easily cleaned by employing a cleaning tool utilized such to enter into the fiber assembly and to separate the single fibers. The protection performance of fibers is known from examples in nature fibers (cilia, hairs in ear and nose) surrounding a cavity or orifice providing excellent protection against dust and particulate debris.
[0056] As mentioned above, the transducer protection system 100 is very easy to clean due to the fact that a tool or brush can directly be introduced into the central opening of the transducer protection system 100. Since the fibers are not connected to each other, the cleaning tool in use will push them aside. The relative movement of the cleaning tool will allow to free entrapped debris or cerumen. The transducer protection system 100 can be easily inserted in and removed from the transducer opening 108 without damaging the protection system 100 itself, the transducer opening 108 or the hearing device 110.
