Hearing aid intended for being mounted within the ear canal

Abstract: An in-the-ear canal hearing aid comprises a microphone (1), an amplifier (2) and an electromechanical transducer (3), for example in the form of a telephone. The hearing aid further includes an extraction means (12) for extracting the hearing aid from the ear canal. The extraction means (13) is in the form of a hollow tube whose one end is mechanically attached to the housing (4,6) of the hearing aid at such a position that the channel in the tube is acoustically coupled to the sound entrance (7) of the hearing aid. As a result, the extraction means (12) has as its second function the suppression of acoustic feedback.

Description: The invention relates to a hearing aid intended for being mounted within an ear canal, said hearing aid comprising a microphone having a sound input, an amplifier and an electromechanical transducer, for example a telephone, accommodated in a housing, and including an extraction means in the form of a tube for extracting the hearing aid from the ear canal, which tube with one end, is mechanically coupled to the housing. Such a hearing aid is known from US-A-4,869,339. The known hearing aid is to be mounted within the end canal. For extracting the known hearing aid from the ear canal, the hearing aid comprises extraction means in the form of a tube which is arranged round the housing of the hearing aid. The fact is that a problem often occurring with hearing aids is the acoustic feedback. In that case there is a too strong sound transfer form the telephone to the input of the microphone, which causes acoutic feedback. It is an object of the invention to propose a different type of extraction means which is able of suppressing acoustic feedback. The hearing aid according to the invention is thereto characterized, in that the tube forms an acoustic channel, which channel is acoustically coupled to the sound input of the microphone by means of an acoustic tube connecting the one end of the tube and said sound input and in that the tube, on its other end, has a free opening which is positioned remote from the housing. WO-A 90/03089 discloses a behind the ear hearing aid having a tube which has a free opening which is positioned remote from the housing containing the microphone, the amplifier and the electro-mechanical transducer. The tube forms an acoustic channel and is connected, with its one end, to the output of the electro-mechanical transducer. This tube may be constructed of a material that is rigid or semi-rigid longitudinally so that the tube may be inserted into the ear canal. This hearing aid aims at reducing acoustical feedback. The measure according to the invention is based on the recognition that with respect to the extraction means a choice is to be made so that also further problems that may occur with a hearing aid can be remedied simultaneously. According to the invention the extraction means in the form of a tube is furthennore used as an acoustic guide of external sound to the microphone input. The acoustic feedback path is thereby extended by roughly twice the length of the tube, which means that a further suppression of undesired oscillations can be realized. The acoustic tube thus has a twofold object. On the one hand the tube serves as an extraction mechanism and on the other hand the tube serves as a means for further suppressing acoustic feedback. There is an additional advantage if the tube is made of a flexible material. In that case the acoustic feedback, which especially occurs if a switched-on hearing aid is extracted, may be avoided by pinching the tube while the hearing aid is being inserted or extracted. The invention will be further explained in the following description of the Figures with reference to an exemplary embodiment, in which: Figure 1 shows a first exemplary embodiment and Figure 2 shows a second exemplary embodiment. Figure 1 shows in a diagram a hearing aid which can be mounted within the ear canal, a so-called in-the-ear canal hearing aid. The hearing aid comprises a microphone 1, an amplifier 2 and an electromechanical transducer 3 which are all accommodated in a housing 4. The housing 4 has an external shape adapted to the internal shape of the ear canal of the user of the hearing aid. The transducer 3 is a telephone (loudspeaker) in the present example. The hearing aid is inserted into the ear canal in such a way that the sound exit 5 of the hearing aid is directed towards the tympanic membrane. The sound output 9 of the telephone 3 is acoustically coupled to the sound exit 5 by way of a tube 10. The housing 4 is shut off by a cover 6 on the side remote from the tympanic membrane. In this cover there is a sound entrance 7 which is acoustically coupled to the sound input 8 of the microphone 1 by means of an acoustic tube 11. The cover 6 may comprise still more components of the hearing aid, such as a volume control, and it may have an opening for inserting a battery which opening may be closed by a button (not shown). The hearing aid further includes an extraction means 12. The extraction means 12 is in the form of a hollow tube 13. One end of the tube 13 is acoustically coupled to the sound entrance 7 in the cover 6. With this one end the tube 13 is furthermore mechanically attached to the cover 6 by means of a grommet 15. The other end of the tube 13 has a thickening 14. The tube 13 has such a length that the user can pull the hearing aid out by the thickening if the hearing aid is embedded in the ear canal. The tube 13 furthermore serves as an acoustic tube through which the external sound signals can be fed to the sound entrance 7 and thus to the microphone 1. The tube 13 extends the acoustic transfer path from the telephone 3 to the input 8 of the microphone 1, so that there is less chance of acoustic feedback. The tube 13 thus not only serves as an extraction means but also as a means for suppressing acoustic feedback. The tube 13 may be made of a rigid or a flexible material. In the latter case one may think of, for example, a piece of silicon hose. In the exemplary embodiment shown in Figure 1 the tubes 11 and 13 are arranged as a single tube. Figure 2 shows a somewhat different embodiment in which the tube 13 and the tube 11 do not form one whole but are each connected with the cover 6.

Claims: Hearing aid intended for being mounted within an ear canal, said hearing aid comprising a microphone (1) having a sound input (8), an amplifier (2) and an electromechanical transducer, for example a telephone (3), accommodated in a housing (4), and including an extraction means (12) in the form of a tube (13) for extracting the hearing aid from the ear canal, which tube, with its one end, is mechanically coupled to the housing, characterized in that the tube (13) forms an acoustic channel, which channel is acoustically coupled to the sound input (8) of the microphone (1) by means of an acoustic tube (11) connecting the one end of the tube (13) and said sound input (8) and in that the tube, on its other end, has a free opening which is positioned remote from the housing (4). Hearing aid as claimed in claim 1, characterized in that the tube (13) is made of a flexible material. Heating aid as claimed in claim 1 or 2, characterized in that the tube (13), on said other end, comprises a gripping means (14). Hearing aid as claimed in claim 3, characterized in that the gripping means comprise a thickening (14).

Inventors: LEENEN JOSEPH RENIER GERARDUS, LEENEN, JOSEPH RENIER GERARDUS MARIA
Applicants: PHILIPS ELECTRONICS NV, PHILIPS ELECTRONICS N.V.
Application year: 1992
Main classification: H04R25
IPC codes: H04R25