EP4601320A1

EP4601320A1 - Earpiece for a hearing device

Info

Publication number: EP4601320A1
Application number: EP24156847.6A
Authority: EP
Inventors: Fabio SCHMIDT; Erwin Kuipers; Andy MÜLLER
Original assignee: Sonova AG
Current assignee: Sonova Holding AG
Priority date: 2024-02-09
Filing date: 2024-02-09
Publication date: 2025-08-13

Abstract

The invention relates to an earpiece (1) configured to be mounted to a hearing device, the earpiece (1) having an outer surface and an inner surface, at least a part of the outer surface intended to contact an ear canal wall of a user's ear when being inserted in the ear canal comprising micro structured features (3).

Description

Technical Field

The invention relates to an earpiece configured to be mounted to a receiver of a hearing device.

Background of the Invention

Instant-fit earpieces such as silicone domes are commonly used in the hearing instrument business. Such earpieces are flexible, easy to manufacture and biocompatible. However, ingress of cerumen into acoustic ports of the earpieces may lead to clogging of said ports. When an earpiece is inserted in the ear canal, cerumen is displaced towards the eardrum, leading to accumulation of cerumen near the medial end of the ear-piece. In addition, relative movements of the earpiece with regard to the ear canal wall lead to migration of cerumen. Both effects contribute to the clogging process. Ultimately, the acoustic output port(s) will be clogged, and the user will suffer from a loss of hearing assistance. In addition, vent perforations can become clogged as well.
Compared to a custom earpiece, the retention of a dome in the ear canal may be considerably worse. Consequently, the dome may move out of the ear canal due to inertial forces associated with head movements. The user may need to push the earpiece over and over again back into the ear canal.

Summary of the Invention

It is an object of the present invention to provide a novel earpiece for a hearing device and a novel method for producing the earpiece.
The object is achieved by an earpiece according to claim 1 and by a method according to claim 14.
Preferred embodiments of the invention are given in the dependent claims.
According to an aspect of the present invention, an earpiece configured to be mounted to a hearing device, e.g. to a receiver of a hearing device, is proposed, the earpiece having an outer surface and an inner surface, at least a part of the outer surface intended to contact an ear canal wall of a user's ear when being inserted in the ear canal, said part of the outer surface comprising micro structured features.
The earpiece may be an instant fit earpiece such as a dome.
The hearing device may for example be a wireless or wired hearing aid for aurally impaired people or a wireless or wired earbud or a hearing protection plug. The hearing device may be a receiver in the canal (RIC) hearing device or a behind the ear (BTE) hearing device having a sound tube, wo which the earpiece may be mounted.
In an exemplary embodiment, at least part of the inner surface comprises micro structured features.
The earpiece may be dome shaped.
In an exemplary embodiment, the micro structured features have a height or depth in a range from 10 µm to 150 µm and/or a width in a range from 10 µm to 150 µm relative to a surrounding surface next to the micro structured features. The height or depth in that range may be determined as an arithmetic average Ra of the roughness profile, a root-mean-squared roughness Rq or a maximum peak to valley height Rz of the profile.
In an exemplary embodiment, the micro structured features have a height or depth relative to the surrounding surface and/or a width of more than 100 µm, in particular at least 110 µm or at least 120 µm or at least 130 µm. These dimensions of the micro structured features on the outside of the earpiece have shown improved capability to remove cerumen, dead skin cells, sebum or sweat from the ear canal so that less of those contaminations will be pushed into the acoustic ports (receiver sound outlet, vent) during insertion and less cerumen will migrate into these ports.
In an exemplary embodiment, the micro structured features comprise circular stripes and/or grooves and/or elevated or recessed spots, preferably arranged in a regular or irregular pattern.
In an exemplary embodiment, the stripes and/or grooves run about the dome shaped earpiece circumferentially or longitudinally or in a spiral way.
In an exemplary embodiment, the inner surface has a portion configured to mount to a sound outlet or a nozzle of the hearing device or a receiver or a sound tube of the hearing device, said portion comprising micro structured features.
In an exemplary embodiment, the earpiece is made of or comprises a compliant or soft material, preferably silicone.
In an exemplary embodiment, the micro structured features extend over more than a mid-zone of the outer surface of the earpiece. The mid-zone may be an area of the earpiece in the middle between a rear end and a forward end, in particular an apex, covering at most 10%, 20%, 30%, 40%, 50%, 60% or 70% of the length of the earpiece.
In an exemplary embodiment, the micro structured features extend over at least two thirds of the outer surface or over at least almost the entire outer surface.
In an exemplary embodiment, the micro structured features are blind holes or clearance holes in the surface of the earpiece, in particular they are not through openings in said surface.
In an exemplary embodiment, the earpiece further comprises an apex having at least one opening, e.g. at least one lateral opening, the apex having a smooth outer surface without micro structured features.
In an exemplary embodiment the micro structured features may have a saw tooth profile, in particular an asymmetric saw tooth profile, improving retention in the ear canal and/or improving the cleaning function when pulling the earpiece out of the ear canal.
According to an aspect of the present invention, a method of producing an earpiece as described above is proposed, the method comprising 3D printing or moulding, in particular injection molding or compression molding the earpiece.
In an exemplary embodiment, the micro structured features are generated by the 3D printing process and/or by laser machining.
The micro structured features on the outside of the earpiece may help to remove as much cerumen as possible from the ear canal so that less cerumen will be pushed into the acoustic ports (receiver sound outlet, vent) during insertion and less cerumen will migrate into these ports.
To this purpose, the outer surface of the earpiece, of which at least a part will be in contact with the ear canal wall, is micro-structured with features as opposed to current designs that typically have a more or less smooth surface. When removing the earpiece from the ear canal wall, the cerumen is transported out of the ear canal by means of these features. Provided that the outer surface of the earpiece will be regularly cleaned, there will be a net transport of cerumen from the ear canal.
Besides cerumen, also dead skin cells, sebum or sweat can be transported from the ear canal.
It is a fact, that once the cerumen has entered the acoustic ports and is inside the earpiece it further migrates on the inner walls of the earpiece towards the receiver. If the inner walls are micro structured as well, the migration of the cerumen (and any other ingress for that matter) would then be slowed down. This is due to the fact that these micro structured features can collect said cerumen.
Further, the solution according to the invention increases friction between the surface of the earpiece and human fingertips compared to smooth surfaces known in the art. This makes handling of the earpieces easier during mounting and/or dismounting on and/or from the receiver.
By adding micro structured features to the outer earpiece surface, the earpiece will have more retention, i.e. more resistance to moving out of the ear canal due to inertial forces that occur during head movement induced accelerations. The features locally lead to an increased contact pressure and associated herewith, an increased small local radial deformation of the ear canal wall. The effect is similar to a profiled shoe sole on soft soil compared to a smooth sole.
To maintain a good wearing comfort, the micro structured features shall remain small in height and size. By doing so, the local pressure acting upon the ear canal wall will only increase slightly compared to current earpiece designs.
In addition, the removal of friction reducing substances from the ear canal (sebum, sweat, cerumen), will also lead to increased friction compared to current earpiece design. This is also beneficial for retention of the earpiece.
By having micro structured features on the inner walls of a silicone dome where the receiver mounts (e.g. nozzle, sound outlet) there will be higher retention forces at the interface between those two components with the result that one could make said interface more compact.
Moreover, the micro structured features may reduce the passage of sound between the earpiece and the wall of the ear canal. This would improve dampening characteristics and reduce leakage of sound (less feedback, more sound pressure). The structure can be beneficial also for hearing protection earpieces.
The hearing device may for example be a wireless or wired hearing aid for aurally impaired people or a wireless or wired earbud.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Brief Description of the Drawings

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, and wherein:

Figure 1: is a schematic view of an exemplary embodiment of an earpiece for a hearing device, the earpiece having micro structured features formed as circumferential stripes elevated above the surrounding surface,
Figure 2: is a schematic view of another exemplary embodiment of an earpiece, the earpiece having micro structured features formed as spots which may be elevated above the surface or which may be recesses in the surface,
Figure 3: is a schematic view of another exemplary embodiment of an earpiece, the earpiece having micro structured features formed as stripes running in a longitudinal direction,
Figure 4: is a schematic view of another exemplary embodiment of an earpiece, the earpiece having micro structured features formed as stripes running in a spiral way, and
Figure 5: a schematic view of an exemplary sawtooth profile of the micro structured features.

Corresponding parts are marked with the same reference symbols in all figures.

Detailed Description of Preferred Embodiments

Figure 1 is a schematic view of an earpiece 1 for a hearing device, the earpiece 1 having an outer surface, at least a part of which is configured to contact an ear canal wall of a user's ear when being inserted in the ear canal and comprises micro structured features 3.
The present invention describes how the surface of a hearing aid earpiece 1 such as a dome can influence and impact the protection from ingress that said dome provides for the hearing aid receiver, the retention of the dome inside the ear-canal, a secure fit and the wearing comfort for the user and the interface of the dome and the receiver which must be secure enough to hold the two components together whilst being as compact as possible.
If at least part of the surface on the outside of the earpiece 1 which touches the ear canal wall has micro structured features 3 such as circular and/or circumferential stripes or grooves, the surface section of the earpiece 1 actually touching the ear canal is decreased while the acoustic seal inside the ear is still ensured. Acoustic sealing is not only achieved by having sufficient contact surface, but also having contact on the entire circumference. Such a surface increases the probability of touching the ear canal wall over the whole circumference.
The main idea is that cerumen (and other substances like sebum and/or sweat) will adhere better to the micro structured features 3 than to smooth surfaces. If the surface of the earpiece 1 is cleaned regularly, these substances are not brought into the ear canal again, so that the ear canal is cleaned. Regular cleaning of the surface of the earpiece 1 is required, for instance by wiping off with an IPA-drenched (isopropanol) cloth, or simply with a wet cloth. To this purpose, the earpiece 1 shall be dismounted from the receiver, to avoid damage to the receiver.
With the micro structured features 3 not only skin cells can get collected, but also ingress from cerumen or sweat. The collection of the substances on the outer surface of the earpiece 1 increases the overall protection of the earpiece 1 by a significant amount.
The earpiece 1 may further comprise an apex 5 having at least one opening, the apex 5 having a smooth surface without micro structured features 3.
Figure 2 is a schematic view of another exemplary embodiment of an earpiece 1, wherein the micro structured features 3 are spots which may be elevated above the surface or which may be recesses in the surface. The spots may be arranged in a regular or irregular pattern or grid.
Figure 3 is a schematic view of another exemplary embodiment of an earpiece 1, wherein the micro structured features 3 are stripes not running circumferentially like lines of latitude on a globe but like lines of longitude on a globe toward a pole or apex.
Figure 4 is a schematic view of another exemplary embodiment of an earpiece 1, wherein the micro structured features 3 are stripes running in a spiral way about the dome shaped earpiece 1.
The earpiece 1 may for example be manufactured by 3D printing. In order for the micro structured features 3 to be cleaned and handled just like any other earpiece, a depth and/or a height of any groove, spot, or stripe should preferably not exceed 150 µm. A minimum depth and/or height of the micro structured features 3 may be 10 µm.
The geometry of the micro structured features 3 (grooves, spots, stripes, etc.) does not alter the mechanical behaviour if it does not exceed said 150 µm. This limitation also prevents difficulties during insertion or removal from the ear canal.
The micro structured features 3 do not result in a haptic difference noticeable by the user and force measurements have showed, that the structural integrity is equal to earpieces 1 that do not have any micro structured features 3. However, if pressure is applied to the surface and the structure of the soft earpiece 1, the retention gets increased and the user experiences a better grip. This better grip helps during mechanical deformation of the ear canal during certain activities (e.g. eating/chewing). These deformations apply pressure to the earpiece 1 and whilst smooth earpieces 1 without any surface structure slowly slide out, earpieces 1 described in this invention show improved retention.
In order to achieve a secure connection between the receiver and the earpiece 1, which may be a soft silicon dome, an interface may be arranged which applies pressure to the soft material of the earpiece 1 to hold the receiver sound outlet inside the earpiece 1. If said inside of the earpiece 1 has small micro structured features 3 similar to the ones proposed above for the outside, the friction of said interface gets increased and it can be designed more compact whilst having the same level of retention force.
Such micro structured features 3 on the surface can be lasered directly onto any mold. The laser removes material and creates a variety of structures. In addition, other very small structures such as text to indicate certain information of the earpiece 1 may be lasered into the mold. The earpiece 1 may be manufactured using techniques such as injection molding or compression molding (with or without laser post processing of the molds) or 3D-Printing.
In an exemplary embodiment, the micro structured features 3 may not be through openings in the surface of the earpiece but rather blind holes or clearance holes.
In an exemplary embodiment, the micro structured features 3 may extend over more than just a mid-zone 4 of the outer surface of the earpiece, e.g. over at least almost the entire outer surface or over at least two thirds of the outer surface.
In an exemplary embodiment, the micro structured features 3 may be structures greater than 100 µm, e.g. at least 110 µm or at least 120 µm or at least 130 µm and at most as big as 150 µm.
Figure 5 is a schematic view of an exemplary profile of the micro structured features 3 in the shape of stripes as shown in figures 1, 3 and 4. The micro structured features may have a saw tooth profile, in particular an asymmetric saw tooth profile, improving retention in the ear canal and/or improving the cleaning function when pulling the earpiece 1 out of the ear canal.

List of References

1: earpiece
3: micro structured features
4: mid-zone
5: apex

Claims

An earpiece (1) configured to be mounted to a hearing device, the earpiece (1) having an outer surface and an inner surface, at least a part of the outer surface intended to contact an ear canal wall of a user's ear when being inserted in the ear canal comprising micro structured features (3).
The earpiece (1) according to claim 1, wherein at least part of the inner surface comprises micro structured features (3).
The earpiece (1) according to claim 1 or 2, wherein the micro structured features (3) have a height or depth in a range from 10 µm to 150 µm and/or a width in a range from 10 µm to 150 µm relative to a surrounding surface next to the micro structured features (3).
The earpiece (1) according to any one of the preceding claims, wherein the micro structured features (3) have a height or depth relative to the surrounding surface and/or a width of more than 100 µm, in particular at least 110 µm or at least 120 µm or at least 130 µm.
The earpiece (1) according to any one of the preceding claims, wherein the micro structured features (3) comprise circular stripes and/or grooves and/or elevated or recessed spots, preferably arranged in a regular pattern.
The earpiece (1) of claim 5, wherein the stripes and/or grooves run about the dome shaped earpiece circumferentially or longitudinally or in a spiral way.
The earpiece (1) according to any one of the preceding claims, wherein the inner surface has a portion configured to mount to a sound outlet or a nozzle of the hearing device or a receiver of the hearing device or a sound tube of the hearing device, said portion comprising micro structured features (3).
The earpiece (1) according to any one of the preceding claims, wherein the earpiece (1) is made of or comprises a compliant or soft material, preferably silicone.
The earpiece (1) according to any one of the preceding claims, wherein the micro structured features (3) extend over more than a mid-zone (4) of the outer surface of the earpiece (1).
The earpiece (1) according to any one of the preceding claims, wherein the micro structured features (3) extend over at least two thirds of the outer surface or over at least almost the entire outer surface.
The earpiece (1) according to any one of the preceding claims, wherein the micro structured features (3) are blind holes or clearance holes in the surface of the earpiece (1).
The earpiece (1) according to any one of the preceding claims, further comprising an apex (5) having at least one opening, the apex (5) having a smooth surface without micro structured features (3).
The earpiece (1) according to any one of the preceding claims, wherein the micro structured features (3) have a saw tooth profile.
A method of producing an earpiece (1) according to any one of the preceding claims, the method comprising 3D printing or moulding, in particular injection molding or compression molding.
The method of claim 14, wherein the micro structured features (3) are generated by the 3D printing process and/or by laser machining.