WO2012149970A1

WO2012149970A1 - Adjustable vent of an open fitted ear mould of a hearing aid

Info

Publication number: WO2012149970A1
Application number: PCT/EP2011/057151
Authority: WO
Inventors: Erdal Karamuk; Pascal KÜNZI; Tobias Poetzl
Original assignee: Phonak Ag
Priority date: 2011-05-04
Filing date: 2011-05-04
Publication date: 2012-11-08

Abstract

Venting means (24, 25, 26) of an open fitted ear mould (21) which are arranged at the medial end of the ear mould comprising a switch or valve-like element (24, 26), integrated in the ear mould being manually operable for opening or closing the venting means.

Description

ADJUSTABLE VENT OF AN OPEN FITTED EAR MOULD OF A HEARING AID

The present invention refers to an open fitted earmold, with venting means according to the preamble of claim 1, a process for the adjustment of the hearing aid settings in order to influence the regulation or position respectively of the venting means.

In the ear worn hearing aids comprise usually so-called vent passages or ducts to ensure a certain pressure

compensation within the ear canal. The cross-section of the vent usually is determined at the production of a hearing aid, the cross-section being usually of a constant value throughout the whole vent. The same of course is also valid for so-called otoplastic parts, earmolds or in-the-ear plugs of hearing aids, e.g. short earmolds that are

connected to a pneumatic tubing or an external receiver.

The disadvantage of such vents is that once included within a hearing aid or earmold, they cannot be adjusted in case of acoustic feedback occurrence, changes of environmental conditions such as noise, special influences like e.g.

music, loud discussions of a variety of persons, etc., e.g. in terms of cross-section variations.

Furthermore, open fittings are a preferred treatment method for mild hearing losses due to their comfort and non occluding acoustic coupling. Mostly BTEs are used in combination with different solutions for acoustic coupling using standard eartips (domes) made of molded soft material such as TPE or silicone rubber in various sizes and with different degrees of venting. These earpieces are put on either a thin sound-tube or an external receiver assembly, which allows further miniaturizing of the hearing aid behind the ear. Additionally there's the option of building custom made eartips (which e.g. are marketed under the name "SlimTip" by Phonak) which consist of a hollow CIC shell with an integrated adapter at the tip into which the sound- tube or external receiver can be clicked in. These custom eartips have the advantage that they provide better

positioning and better retention in the ear. Additionally, the acoustic leakage can be controlled by means of venting. The most open solution is called a Cavity vent' which consists only of a hole at the medial end of the shell near the sound outlet.

Thus the acoustic mass of the vent is only given by the diameter (or area in cases of non-circular holes) of the hole and the wall thickness of the shell, which is about 0.4 to 08 mm depending on the shell material. This

arrangement allows the most open fitting and has minimal impact on the natural acoustic coupling, as the natural resonance of the ear canal (Open Ear Gain, OEG) is largely preserved. However, by using advanced features such as ^ΛAcoustically Optimzed Venting' (AOV) a technology by

Phonak for optimal vent design, the fitter has the

possibility to define the acoustic coupling function by adding different vent styles into a SlimTip and thus find the optimal balance between comfort (less occlusion) and clarity (better understanding) .

This invention aims at further optimizing the design of such eartips by adding an adjustable venting element which gives the end user the control over the amount of leakage or attenuation respectively.

Many concepts for adjusting a venting or modifying the transfer function through a vent (both sides) have been described in the literature.

E.g. within the DE 100 13 695 or the DE 199 42 707

solutions are proposed to influence the cross-section by arranging a valve-like installation to reduce or even totally close the _. cross-section of the vent line. The proposed solutions are not very user friendly, as a manual operation by a user is rather impossible. Within the

DE 4 008 982 Al switching element in the venting channel, accessible from the outside by a tool is described, which allows to locally adjusting the cross-section of the vent. Within the DE 4 010 372 Al, a system for active feedback reduction by means of a second receiver that can cancel sound waves in the vent is disclosed. An adjustable venting mechanism for an ITE using an electromechanical actuator is disclosed within the DE 19942707 Al, to open and close a valve in the vent canal. Further, the US 6 819 770

describes an active arrangement with multiple venting channels, which promotes the air flow from the outside to the residual volume and back, thus creating a good ventilation. The active means are driven electrically.

Within the DE 10154390 Al a filter element in the vent is described that allows a frequency-dependent filtering of feedback-relevant signals. Within the EP 2 071 872 Al adjustable venting mechanism for an ITE using an

electromechanical actuator is disclosed to open and close a conical valve in the vent canal. Finally, in WO2010042613A2 various possible configurations for an acoustic switching element are disclosed using mechanical, electromagnetic or electrostatic actuation. The main limitation of those concepts is their complexity which is critical with regard to reliability and size. The larger the actuation mechanism becomes, the smaller will be the available air volume in the earmold which reduces the venting effect.

The main problem of open fittings is the control of direct sound that reduces the performance of the hearing aid. Due to the OEG which is mostly left intact by open fitting (even with SlimTips) the SNR of the direct sound to the processed signal is further reduced, by up to lOdB 1 a frequency range of 1500 to 3000 Hz, which is most critical for understanding of speech. This leads to the paradox situation that especially in those situations where the hearing aid and its advanced DSP features for beam-forming and noise cancelling would be most valuable the performance is dramatically reduced by the bad SNR. In those situations it would be desirable to switch the acoustic coupling from an open fitting into a closed fitting. This can be achieved by a user-controlled switch or valve that allows switching between open and close states of the venting of the eartip. Another typical use case is a phone call that is directed to the users hearing instruments by means of a wireless transmission from the phone. In this situation the

surrounding direct sound is totally unwanted and should be blocked if possible.

Requirements for an adjustable venting system for an open fitted eartip are decried below:

• Minimal space or volume occupation to leave the shell as "empty" as possible

• Minimal (better none) power consumption

• Manual actuation in the ear without removal of the hearing aid

• Good sealing in the closed state for optimal

attenuation

• Minimal occlusion in the open state

• Reliable and easy to clean

The invention consists of a valve element that is

integrated into the tip or the medial end of the earmold at the place, where normally the cavity vent is located. The object of the present invention is to propose a user friendly solution to influence and operate the venting means, which means the opening and closing of the venting means.

According to the present invention a fitted ear mold, such as e.g. an in-the-ear hearing aid and/or an eartip with venting means is proposed according to the wording of claim 1.

According to one aspect, it is proposed that at the in-the- ear hearing aid or at the eartip a manually operatable switch is arranged for closing, opening or optionally partly opening of the venting means, the venting means consisting of a switch, such as a valve-like toggle switch, which is rotatably operatable around an axis, which is laterally displaced from the centre axis of the duct resulting in a non-rotation-symmetric assembly.

According to one embodiment, the switch may comprise a spherical joint.

Further, it is proposed to have so-called "lock positions" at the toggle switch to fix the switch within predetermined positions such as closed, open, partially open, etc.

Due to one aspect, it is proposed that the valve-like toggle switch is arranged near the entrance of a vent duct, which means visible from the outside of the hearing aid or ear plug, which means that it can easily manually be operated by a user person. In other words, a user person can operate the switch before entering into certain

acoustic environments such as e.g. street noise, quiet environment, music concert, etc., knowing the influence of the switch position to the acoustic performance of the hearing aid. According to a further aspect, it is proposed that a valve element is integrated into the tip of the eartip at the place, where normally the cavity vent is located. The valve may have e.g. two states:

Open: sound flows as in the arrangement of a cavity vent through a small opening on the shell

Closed: sound from the outside is blocked or directed through a more attenuating passage. The valve is activated by an external mechanical access. One possibility is to use the removal cord, which is already in place for most EarTips. This removal cord (also called fish-line, because of its material) is a polymer monofilament fiber. Thus by carefully selecting the

material and cross-section this fiber-like element can be designed in such a way that it would allow to transmit compressive, tensile and torsional forces, thus allowing to use the removal cord to actuate a valve in the two states. It is further proposed that means are provided to register the status of the switch and the related passage opening of the vent duct, the status influencing a program adjustment arrangement within the hearing aid to adjust the settings of the hearing aid. The program adjustment arrangement could be fitted or optimized during the fitting process of the hearing aid, by positioning the vent closing switch in various different positions within different acoustic environments. In that respect, it is further proposed to include a sensor within the hearing aid to receive any acoustic feedback in case the vent duct is at least partially open. Again, by receiving a certain acoustic feedback, settings of the hearing aid can be influenced by a program adjustment arrangement. This sensor could be an algorithm in the DSP acting as a ^Λ feedback sniffer'

registering any change in the acoustic transfer function between sound exit (in the ear) and the feedback signal reaching the microphone. As this transfer function will be different in both states of the valves - stronger when open and weaker when closed - it serves a signal to trigger the algorithm to change respective settings in the hearing aid.

Further, designs and embodiments of the present inventions are characterized within dependent claims.

Further proposed are processes to operate the venting means in an earmould according to the wording of claims 13 and following .

The invention shall be described with the aid of examples and in relation to the attached figures.

The figures show:

Figure 1 an inventive switch in perspective view;

Figure 2 the arrangement of an inventive switch within a faceplate of an in-the-ear hearing aid;

Figure 3 and 4

a cross sectional view of the inventive switch in different positions; Figure 5 a further possible embodiment of the present invention, showing a cylindrical guidance

integrated within an eartip element, enabling opening or closing of the venting means ;

Figure 6 a similar cylindrical guidance integrated,

showing a different mechanism for opening and closing the venting means;

Figure 7 a further embodiment of the present invention, showing actuating means for opening and closing the venting means;

Figure 8 again a further embodiment of the present

invention, for closing and opening the venting means, and

Figure 9 in cross-sectional view, a further embodiment of the present invention, again for closing or opening the venting means.

Figure 1 shows in perspective view an inventive vent-like toggle switch 2 for closing, opening or at least partially opening a vent duct of an earmold such as an in-the-ear hearing aid or an in-the-ear plug. The switch comprises a switch casing 1 and an actuating lever 3 for the actuation of the switch. The position as shown in figure 1 is the open position so that the passage 5 through the switch into the vent duct is open.

Figure 2 shows again in perspective view the arrangement an inventive switch 2 within a faceplate 7 of an in-the- hearing aid. Again visible is the switch 2 in open position, so that the passage 5 to the vent duct is open. Further, arranged within the faceplate is the volume- regulating switch 9, the microphone opening 11 and program selection switch 13. Even if the switch 2 is relatively small, due to the arrangement of an actuating lever 3 as shown in figure 1 projecting out of the faceplate it can easily be manually operated.

Figures 3 and 4 show in sectional view different positions of the inventive switch 2. Within figure 3 the position of the actuating lever 3 is such that the switch is in open position, so that the passage 5 is completely free to the vent duct of e.g. a hearing aid. As further can be

recognized the rotation axis RA of the lever 3 is displaced in relation to the axis of the passage 5 or the vent duct being arranged behind the switch 2. In other words, the actuating switch is not rotation symmetric to ensure that the cross-sectional area in open condition can be maximized and at the same time it is possible to define an optimal sealing edge 8 in closed condition, as shown in figure 4. In other words, the proposed actuating switch shows the following features:

- asymmetric arrangement (non-rotation-symmetric)

- the switch comprising a spherical joint to ensure good sealing and easy mounting conditions

- several locking positioning elements to fix the switch in various positions such as the shown two end

positions - outer casing or collar 1 for fixing the switch within the faceplate.

As an alternative the switch could be arranged directly as an integral part within the faceplate.

A further advantage of the proposed actuating switch is that it is mechanically actuatable and further can be arranged to an in-the-ear hearing aid or an in-the-ear plug as an additional part.

The following embodiments, shown in cross-sectional view in figures 5 to 9, are mainly focused on custom earmolds

(SlimTips) . The same principal is however applicable to standard-sized eartips (domes) if the design can be

realised small and cost effective enough. Here the venting is placed at the medial end of the earmold and consists of a hole in the shell (cavity vent) that can be opened or closed by external actuation of a mechanical assembly built into the earmold.

In contrast to the vent like toggle, switch as shown in figures 1 to 4 within figure 5 a cylindrical guidance 25 is integrated into the shell 21 of an earmold or an eartip respectively. The cylindrical guidance 25 is similar to a regular venting duct as described with respect to figures 1 to 4. A plug 24 is mounted slideable in the cylindrical guidance and can be moved by using a cord 22, which is projecting out of the guidance, so that the plug 24 can be activated by external access. A cap 23 will close the top end of the guidance. Depending on its position, the plug 24 will either close or open a hole 26 in the side wall of the guidance, which will enable the venting. The cylindrical guidance could be integrated directly into the shell during the digital manufacturing process. This results in a cost effective and good processable concept.

Figure 6 furthermore, shows a similar embodiment, where the function is the same as in figure 5, unless the plug 24 is replaced by a strap 27. Therefore, the guidance may have e.g. a rectangular cross-section. The advantage is that the strap 27 can cover a large hole diameter of hole 26 by require a minimal total height. Figure 7 shows a different embodiment, where a bistable sheet metal 34 is embedded in a cage 33. The cage 33 is placed e.g. by gluing in the shell 21 at the shell end 21 directed towards the interior of the ear canal. With a cord 22 the bistable sheet metal 34 can be actuated from an open to a closed condition of the vent opening 36. The advantage of this embodiment is that the mechanism is simple and robust. Self cleaning character is achieved during shift between open and closed condition. Figure 8 shows again means for opening or closing the venting directed towards the interior of the ear canal. A flexible tube 44 is placed within the shell 21. In the side wall of the flexible tube a hole 32 is arranged together with a loose flap 45, which is open by default. A moveable cotter pin 47, connected to the cord 22 will close the flap 45, hence the hole 42 will be closed. The cap 43 closes the top end of the flexible tube 44. This concept is not applicable for custom shells only, an integration into a closed dome with standard geometry is possible too.

Flexible components simplify the sealing.

In figure 9 a magnetic plug 57 can be actuated by the cord 22. Magnets 54 will define the position of the magnetic plug 57 which will either open or close a venting hole 52 in the shell 21. The magnets 54 and the plug 57 are carried in a housing 53 which is placed in the shell 21. The advantage of this embodiment is that the magnetic mechanism needs no exactly defined mechanical stop. It can compensate a certain tolerance range or wax contamination of the venting hole.

The great advantage of all the above mentioned and

described solutions is that any kind of a switch or a valve can be activated by an external mechanical access. The embodiment, as described with respect to figures 1 to 4 , is using an actuating lever and within the embodiments, as described with respect to figures 5 to 9, the use of an actuating cord is described. In other words, opening or closing of venting means for open fitted earmolds, such as e.g. in-the-ear hearing aids, in-the-ear plugs tips or molds is possible by an easy external mechanical access, while a large difference between 'open' and 'closed' is still perceived due to the short length of the vent consisting mainly of the medial wall thickness of the earmold .

The result of an open vent duct could be an acoustic feedback which could lead to disturbance of the hearing aid operation. With the opening and closing of the vent the acoustic coupling of the hearing aid to the user is changed, which needs to be compensated in the settings of the hearing instrument for optimal hearing performance. It is thus a fundamental part of the current invention, that the hearing aid has means to detect the state of venting and act accordingly. This means could be a function within the hearing aid DSP algorithm to continuously monitor the feedback threshold level of the acoustic coupling. This algorithm within the hearing aid could detect such acoustic feedback signals and influence a respective program

adjustment arrangement for the adjustment of the hearing aid settings, so that the acoustic feedback could at least be reduced to an acceptable level or a different program setting could be activated. This can be "learned" during the fitting process, by measuring the so-called "feedback threshold", twice, once with an open and once with a closed vent. The respective values shall be registered. The hearing aid is now in a position at the manual actuation of the venting means by a user to change into a respective program.

Possible use cases are: - closing the vent for better sound quality at streaming of music: no vent loss for low frequencies and no disturbing direct sound;

- Closing the vent at high environmental noise as e.g. within a train station hall for suppressing the direct noise at open adaptation;

- Opening of the vent for maximal comfort and minimal occlusion in quiet environment.

Claims

1. Open fitted earmold, comprising venting means at the medial end of the earmold, characterized in that the venting means comprises a switch or a valve-like element, integrated in the earmold being manually operable for opening or closing the venting means.

2. Earmold according to claim 1, characterized in that the valve or switch like element being activable by

external access such as mechanical access.

3. Earmold according to one of the claims 1 or 2, characterized in that the switch or valve-like element being operable with external access, by means of a cord, which is projecting to the exterior of the mold.

4. Earmold according to one of the claims 1 to 3, characterized in that the venting means comprising a valvelike toggle switch, which is rotatably operable around an axis, which is laterally displaced from the centre axis of a duct of the venting means, resulting in a non-rotation symmetric assembly.

5. Earmold according to claim 4, characterized in that the valve-like toggle switch comprises a spherical joint.

6. Earmold according to one of the claims 4 or 5, characterized in that lock positioning means are provided in the valve-like toggle switch provided to fix the switch in predetermined positions, such as closed, open, partially open, etc.

7. Earmold according to one of the claims 1 to 3, characterized by a cylindrical guidance integrated in or near a side wall of the mold, a plug or strap like actuator being slideable mounted in the guidance to open or close a hole in a sidewall of the guidance by use of an external operable cord like element.

8. Earmold according to one of the claims 1 to 3, characterized in that a cage or tube-like installation is arranged near an earmold wall opening directed towards the interior of the ear canal with a hole opening directed to the interior of the earmold to enable venting communication between the earmold and the ear canal, the cage or tubelike installation further comprising actuating means operable by use of a cord, which is projecting out of the exit of the mold for opening and closing the venting means.

9. Earmold according to claim 8, characterized in that the actuating means comprising a bistable sheet metal, which is embedded in the cage, the bistable sheet being actuated from an open to a closed condition or vice versa by use of a cord.

10. Earmold according to claim 8, characterized in that the actuating means being a moveable cotter pin, combined with a loose flap covering the hole to the interior of the mold, the cotter pin being moveable by the external

accessable cord for opening or closing the loose flap to operate the venting means.

11. Earmold according to claim 8, characterized in that the actuating means comprising magnets, which will define the position of a magnetic plug to open or close the venting holes of the venting means, the magnets being actuatable by the cord projecting to the exterior of the mold .

12. Earmold according to one of the claims 1 to 3, characterized in that near a hole within the sidewall of the earmold directed into the interior of the ear canal, a housing with venting openings towards the interior of the mold is arranged in connection with the hole in the

sidewall of the earmold, within the housing further

arranged is a threaded bolt turnable by a screw driver to either open or close the venting openings within the housing for actuating the venting means.

13. Process to operate venting means of an earmould, characterized in that the change of the opening status of the venting means is executed manually by actuating a plug or strap-like actuator by use of an external operable cordlike element, which plug or strap-like actuator is

slideably arranged in a guidance, integrated within the earmould.

14. Process to operate venting means of an earmould, characterized in that the change of the opening status of the venting means is executed manually by operating

actuating means arranged in a cage- or tube-like

installation arranged near an earmould wall opening

directed towards the interior of the ear canal with a hole opening directed to the interior of the earmould to enable venting communication between the earmould and the ear canal, the actuating means being operated by means of a cord which is projecting out of the exit of the mould for opening and closing the venting means.

15. Process according to one of the claims 13 or 14, characterized in that by means of the cord-like element the venting means is manually actuated between predetermined positions such as "closed", "open" or "partially open".

16. Process according to one of the claims 13 to 15, characterized in that the operable cord-like element is the same cord-like element by use of which the earmould can be removed out of the ear canal.