CH691944A5 - Hearing aid with external FM transmitter includes receiver mounted behind ear, and amplifier and speaker accommodated within ear - Google Patents

Abstract

The hearing aid system comprises a three major components: a frequency modulated signal transmitter (1); a relay station (2) comprising an FM signal receiver (22) situated behind the user's ear; and a hearing aid (3) shaped to be accommodated entirely inside the user's ear. The hearing aid system comprises a frequency modulated signal transmitter (1) and a relay station (2) comprising a battery (20), an FM signal receiver (22) and an induction coil (23) connected to the output of the receiver. This is situated behind the user's ear. A hearing aid (3) is shaped to be accommodated entirely inside the user's ear, and comprises a battery (30), a second induction coil (31) receiving signals emitted by the first induction coil, and amplifier (32) and a loudspeaker (33) applying the sound signals to the ear drum. The FM receiver comprises a single integrated circuit using mixed bipolar-CMOS technology, with its output connected directly to the first coil without an intermediate amplifier. The only controls are an access for the battery (20) and an on-off switch (24).

Description

1

CH 691 944 A5

2

Description

The present invention relates to a hearing aid system, more particularly a hearing aid system with FM radio link (frequency modulation).

Frequency modulation (FM) radio systems are often used to transmit sound information over widely varying distances. They are also used in the field of hearing aid systems, for example intended for people suffering from hearing impairments. In classes for children with hearing problems, FM systems are generally used, for example, which consist of a microphone with FM transmitter for the teacher and individual FM receivers connected to the hearing aid devices, the students are provided. These systems have in particular the advantage of a good understanding for all students, regardless of their distance from the teacher, and regardless of ambient noise or acoustic reverberations in the room.

Known FM receivers are generally in the form of a box having approximately the dimensions of a packet of cigarettes, and attached to the belt. This receiver is generally electrically connected to the hearing aid by wires which are very inconvenient for the listener. A system of this type is marketed by the applicant under the trade name "Microvox".

Patent application WO 92/11 738 describes a solution in which the connection between the FM receiver and the hearing aid is wireless. The output of the FM receiver, generally worn on the belt, is connected via an amplifier to an induction coil worn around the listener's neck. The listener's hearing aid is located in the magnetic field generated by the induction coil. Conventional hearing aids are often equipped, in addition to their microphone, with a magnetic field receiving coil (induction coil, or "telecoil"); this induction coil makes it possible to pick up magnetic fields emitted for example by a telephone handset or an induction loop fitted to certain conference rooms. This operating mode is usually indicated with the letter "T" for telephone, and can most often be disconnected by means of a suitable switch. By using such a hearing aid in the magnetic field emitted by the induction coil worn around the listener's neck, it is thus possible to hear the demodulated audio signals by the FM receiver.

Document FR 2 648 294 describes a similar FM system, in which the induction coil connected to the FM receiver can also be worn around the belt. However, these systems have the disadvantage of being relatively heavy and bulky, particularly for young children. It is also difficult to always carry the induction coil with you. In addition, these systems are relatively electrically intensive, in particular because of the relatively high power required to power the induction coil.

An object of the present invention is therefore to propose an improved hearing aid system, in particular a system which is more comfortable and lighter to wear.

This object is achieved according to the invention by means of a relay station having the features of the independent claim, preferred features being further indicated in the dependent claims.

In particular, this object is achieved by means of a relay station carried directly behind the listener's ear flag, in the manner of a post-ear hearing aid device. The relay station includes autonomous power supply means, reception and demodulation means for FM signals, as well as an induction coil directly connected to the output of said demodulation means, all of these elements being entirely housed in a housing. can be worn directly behind the ear pin. The induction coil emits a magnetic field picked up by a second coil (“telephone” coil) in a hearing aid housed in the auditor's external auditory canal.

Given the very short distance between the relay station and the in-ear hearing aid, the induction coil of the relay station can be extremely miniaturized until it fits in the casing of the relay station. In addition, no amplification of the demodulated signals is necessary, which is particularly advantageous for the power consumption of the system.

The invention will be better understood using the description given by way of example and illustrated by the single appended figure which shows a schematic view of the whole system of the invention.

The system of the invention mainly comprises a micro-transmitter 1, a relay station intended to be carried behind the ear pin 2, and a hearing aid device 3. The micro-transmitter 1 is intended to be placed in the immediate vicinity of the sound source, and can for example be used as a simple hand microphone. It essentially comprises a microphone 10 connected to a frequency modulation transmitter 11. The transmitter 11 is preferably supplied by an autonomous electrical supply device 13, for example by a battery. The ambient sounds converted into electrical signals by the microphone 10 modulate the frequency of a high frequency carrier in the transmitter 11, and the signal thus modulated and preferably amplified by an amplifier not shown are emitted by an external antenna 12 or preferably fully housed in the micro transmitter 1 housing.

The micro-transmitter 1 may however also consist of any suitable frequency modulation transmitter, for example by a transmitter broadcasting radio programs, or by a module which can be connected to a device such as radio, television, equipment. stereo, or public address system for converting the audio signals produced into HF radio frequency frequency modulation signals.

To receive signals from the micro5

10

15

20

25

30

35

40

45

50

55

60

65

2

3

CH 691 944 A5

4

transmitter, the listener must be equipped with an in-ear hearing aid 3 as well as a relay station 2 according to the invention. Hearing aid 3 is intended to be housed in the external auditory canal of the listener. It essentially comprises a microphone 35, making it possible to pick up ambient sounds, but which is however not essential for the present invention. An amplifier 32 powered by a battery 30 amplifies the audio signals collected by the microphone 35 so as to actuate an electroacoustic transducer 33 which converts these amplified signals into sound signals transmitted via a channel 34 near the eardrum of the listener.

In a known manner, the hearing aid 3 further comprises an induction coil 31 also connected to the amplifier 32. The coil 31 picks up the magnetic fields passing through the hearing aid 3 and transforms them into audioelectric signals also amplified by the amplifier 32. This coil 31 is generally known as a telephone coil, since it is usually used to amplify the magnetic fields produced by a telephone handset.

The hearing aid 3 also preferably includes handling elements which are not shown, for example a switch making it possible to choose between the input “M” connected to the microphone and the input “T” linked to the inductive coil, and a thumbwheel. volume control.

The relay station 2 of the invention mainly comprises a frequency modulation receiver 22 capable of receiving and demodulating the FM signals transmitted by the micro-transmitter 1 and collected by an antenna 21. The FM receiver 22 preferably consists of a single integrated circuit with low consumption, preferably produced in mixed bipolar technology (for the high frequency circuit portions) and CMOS (for the other circuit portions), for example BICMOS. An example of a receiver circuit on a single integrated circuit is described in patent application EP 671 818, the content of which is here reproduced in full by reference. The receiver 22 is powered by autonomous electrical supply means, preferably by a battery 20 housed in a compartment, for example in a drawer, removable to allow the replacement of the battery.

The output of the receiver 22 directly feeds a small induction coil 23 entirely housed in the casing of the relay station 2. The casing of the relay station 2 is adapted to allow the listener to carry it directly behind the ear pin , like a post-aural hearing aid. In this position, the distance between the transmitting induction coil 23 of the relay station and the receiving coil 31 in the in-ear hearing aid is at most a few centimeters; this characteristic makes it possible on the one hand to reduce the size of the coil 23 in order to accommodate it in the housing 2, and on the other hand to eliminate the need for amplification of the demodulated signal supplied by the receiver 22.

The signals demodulated by the receiver 22 are converted into magnetic fields at audio frequency by the coil 23, and transmitted through the auricle to the telephone coil 31 which again converts them into electrical signals supplying the input of the amplifier 32. The amplifier 32 directly supplies the electroacoustic transducer 33 which converts the amplified signals into sound pressures exerted on the eardrum of the listener.

Apart from the housing already mentioned for the battery 20, the only manipulation member for the relay station 2 is constituted by an on-off button 24. The listener wishing to receive the sound information emitted by a transmitter 1 can therefore do so very simply by placing the relay station 2 behind the ear, by putting the switch 24 in the "on" position, and if necessary by choosing the "T" position (connection of the coil 31 with the amplifier 32) on his hearing aid 3.

In the context of the same invention, the frequency-modulated link between the transmitter 1 and the relay station 2 can be replaced by any type of suitable wireless link, for example by an amplitude-modulated radio link or phase, by a digital radio link, or by an infrared link. The receiver 21-22 in relay station 2 will then have to be adapted to the characteristics of the chosen transmission signals.

Claims (7)

Claims 1. Relay station (2) for hearing aid system, comprising: autonomous electrical supply means (20), reception and demodulation means for modulated electromagnetic signals (22), a first induction coil (23) connected to the output of the demodulation means (22), characterized in that said relay station (2) including said first induction coil (23) are fully housed in a housing which can be worn directly behind the user's ear canal. 2. Relay station according to the preceding claim, characterized in that said electromagnetic signals are high frequency signals modulated in frequency. 3. Relay station according to one of the preceding claims, characterized in that the reception and demodulation means are constituted by a frequency modulation receiver constituted by a single integrated circuit (22). 4. Relay station according to the preceding claim, characterized in that said integrated circuit is produced in mixed bipolar-CMOS technology. 5. Relay station according to one of claims 3 or 4, characterized in that the output of said integrated circuit (22) is directly connected to said first induction coil (23), without intermediate amplifier. 6. Relay station according to one of the preceding claims, characterized in that the only manipulation members of said relay station are constituted by a housing for said electrical supply means (20) and by an on-off switch (24 ). 5 10 15 20 25 30 35 40 45 50 55 60 65 3 5 CH 691 944 A5 7. Hearing aid system, comprising the following separate components: - a transmitter of modulated electromagnetic signals (1), - a relay station (2) according to one of the preceding claims, capable of receiving and demodulating the signals transmitted by said transmitter (1), - a hearing aid device (3) capable of being entirely housed in the external auditory canal of a user and comprising autonomous electrical supply means (30), and provided with a second induction coil (31) adapted to receive the signals emitted by the first induction coil (23), and means (32, 33) for converting the signals received by the second induction coil into sound signals applied to the eardrum of the user. 5 10 15 20 25 30 35 40 45 50 55 60 65 4