WO1996003848A1

WO1996003848A1 - Hearing aid

Info

Publication number: WO1996003848A1
Application number: PCT/DE1995/000853
Authority: WO
Inventors: Johann Vielberth
Original assignee: Institut Für Entwicklung Und Forschung Dr. Vielberth Kg
Priority date: 1994-07-21
Filing date: 1995-07-01
Publication date: 1996-02-08

Abstract

In an electric hearing aid which makes it possible for the hard of hearing to take part in event, e.g. lectures and musical performances, etc., the acoustic signals received by microphones are digitally processed by means of individual transmission functions and the processed digital signals are then converted into analog audio signals for reproduction in headphones.

Description

Hearing aid

The invention relates to a hearing aid according to the preamble of claim 1.

In particular, portable electrical hearing aids are known in various designs. In its simplest form, such a hearing aid consists of a microphone, a hearing amplifier and a receiver controlled by the amplifier, for example ear plug-in earphones. A disadvantage of these hearing aids is that the frequency response and / or the transfer function of the hearing amplifier can only be adapted to the specific hearing impairment of the user to a very limited extent, e.g. the (hearing impairment) in certain frequency ranges an increase and / or in other frequency ranges a reduction in the degree of amplification is necessary in order to at least somewhat compensate for existing hearing damage.

It is also known in hearing aids to achieve a transmission function with a frequency response optimally adapted to the hearing impairment of the user by digitally processing a sound or audio signal supplied and digitized by a microphone. For this purpose, the input signal supplied by the microphone is first converted into a digital signal in an analog-to-digital converter, which is then subjected to a program in an arithmetic unit or processed with a predetermined program that is matched to the hearing impairment of the respective user. The processed sound signal is then converted into an analog audio signal in a digital-analog converter and fed to the listener via an amplifier.

The object of the invention is to show a hearing aid that has improved quality with little effort. To solve this problem, a hearing aid is designed in accordance with the characterizing part of patent claim 1.

The hearing aid according to the invention is designed, for example, as a portable hearing aid. Furthermore, the hearing aid according to the invention is preferably also designed such that the hearing amplifier forms a stationary device which is then connected to a receiving device via the transmission link, which is preferably a wireless transmission link and is preferably an infrared transmission link. This is small and handy and therefore carried out by the user easily and inconspicuously portable. Especially in this version with a stationary hearing amplifier, the device is suitable for connection to existing audio systems, for example to radio sets, stereo systems, television sets, etc.

In the hearing aid according to the invention, the sound signal is transmitted stereophonically, i.e. there are two audio channels, each of which is assigned to at least one earpiece for each ear of the user, the transmission functions, i.e. Transmission and filter curves for each channel are stored individually adapted to the hearing damage of the left and right ear and are taken into account when processing the digital audio signals. An individual frequency-dependent dynamic adaptation is also preferably carried out in the invention, i.e. an individual and frequency-dependent adjustment of the gain depending on the amplitude of the respective input signal.

In a preferred embodiment, the processing of the sound signal of the right and left channel takes place at different times, ie in the time-multiplex method, the switching frequency being well above the audible frequency range, ie well above 20 kHz. In the invention, the listeners are, for example, components of a headphone, on which the microphones are then also provided, so that they have the required spatial distance from one another and are carried at a location which ensures optimum reception and also corresponds best to natural hearing.

In a preferred embodiment of the invention, in addition to the individually stored filter or transmission curves, standardized transmission or filter curves are also stored, which take into account the general acoustic conditions in different local areas, for example in small rooms, large halls, outdoors, etc. which are superimposed on the individual curves in order to achieve an overall transfer function that is also adapted to the local conditions as possible.

In the case of the invention, the voltage and power supply takes place from a power supply unit and / or from one or more batteries, which are preferably rechargeable batteries, in which case the analog circuits, namely the output amplifiers for controlling the listeners, the input or microphone amplifiers, etc. are directly connected to the voltage or power supply, while the digital circuits are operated by the voltage supply via a DC / DC converter, which means that there is a coupling between the digital ones, especially if the power supply has a higher internal resistance or if the battery has a weakened internal resistance Circuits and the analog circuits in the field of power supply is reliably achieved.

The hearing aid according to the invention preferably also has the possibility of self-audiometry, ie the hearing aid has, for example, an audiometry device, so that the respective user is able to do so at home and without the help of a specialist (hearing care professional and / or doctor) his Hearing impairment or impairment of hearing optimally adapted transmission functions for both clocks to be individually determined and stored in the device.

The possibility of self-audiometry results in further significant advantages. On the one hand, the audiometry can be carried out under real conditions and where the hearing aid is actually to be used, taking into account the acoustic conditions prevailing at the place of use, etc.

Since the self-audiometry with the hearing aid, i.e. using the components of the hearing aid (in particular also the listener, etc.), the acoustic properties of these components are also taken into account in the audiometry.

The hearing aid according to the invention is in principle also suitable as a hearing amplifier for the telephone.

Developments of the invention are the subject of the dependent claims.

The invention is explained in more detail below with reference to the figures using exemplary embodiments. Show it:

1 shows a very simplified block or functional diagram of a first embodiment of the hearing aid according to the invention;

FIG. 2 shows a more detailed block diagram of the hearing aid according to FIG. 1;

3 shows a further possible embodiment of the hearing aid according to the invention. The hearing aid shown in FIG. 1, which enables hearing-impaired people to take part in conversations, discussions, lectures, music events, etc., consists of two microphones 1 and 2, two loudspeakers or listeners 3 and 2, in accordance with the very simplified functional diagram of FIG. 1 4, the latter being part of a headphone for stereophonic hearing, namely the speaker 3 for a left and the speaker 4 for a right channel, and from the hearing amplifier 6.

The microphones 1 and 2 are spatially offset from one another, specifically the microphone 1 for the left channel and the microphone 2 for the right channel. Preferably, the two microphones 1 and 2 are also attached to the headphones or to a bracket of these headphones. The aforementioned elements are connected via a flexible multi-wire line 5 to the hearing amplifier, which is generally designated 6 in FIG. 1.

FIG. 2 shows the design of the device generally designated G1 there or of the hearing amplifier 6 in more detail. The central element of the hearing amplifier is a microprocessor 7. These are assigned:

A non-volatile memory 8 in the form of an EEPROM for storing special transmission curves; a memory 9 in the form of a ROM for storing programs, a clock 10; an interface 1 1 for reading in and reading out data and / or

Programs; an input element 12 for manual input of commands, for example for switching on and off, switching etc. of the device or various functions and a CODEC module 13, which has at least two analog-digital converters for converting the analog audio signals of microphones 1 and 2 into digital signals and at least two digital-analog converters for converting digital audio signals back into analog audio signals. Signals for their reproduction on the speakers 3 and 4.

The hearing amplifier 6 also contains a circuit 14, for each microphone 1 and 2 an input amplifier 15, which is connected on the input side to a microphone 1 or 2 and on the output side to the analog-digital converter of the CODEC circuit 13, and two output amplifiers 16 has, each of which is connected with its input to the output of a digital-to-analog converter of the CODEC circuit 13 and with its output to a loudspeaker 3 or 4.

The hearing amplifier 6 finally has a power supply 17 formed by a plurality of batteries, preferably a plurality of rechargeable batteries, to which the circuit 14 or the amplifiers 15 and 16 there are connected directly. The remaining elements of the hearing amplifier 6, in particular all digital circuits or elements for digital data processing, especially also the CODEC circuit 13, are connected to the voltage supply 1 via a direct voltage-direct voltage converter (DC-DC converter) 18. In this way, decoupling between the digital circuits and the analog circuits is also achieved in the area of the voltage supply, in order to effectively avoid interference.

In the case of a stationary device or hearing amplifier, for example, the power supply is formed by an internal or external power supply unit to which the hearing amplifier can be connected. The microprocessor 7 with the components assigned to it essentially serves to achieve a predetermined frequency response or a predetermined pass curve (transfer function) for the hearing amplifier 6, taking into account special transfer or filter curves that are stored for the respective user and take into account their hearing impairment individually, as well as other standardized filter curves that do not take into account the specific hearing impairments of the respective user, but are generally valid and take into account special environmental conditions under which the hearing aid is used for optimal hearing, for example by filtering out low frequencies and / or high frequencies or noise etc.

These standardized filter curves, which are then superimposed on the individual filter curves, can be called up or activated manually via the input 12, the input for this being made easier to use with easy-to-understand user instructions, for example “listening in the room”, hearing outside of buildings ”, "Treble", "Down", etc. has function keys provided.

The filter curves are each stored as a data record, for example in the memory 8. The individual filter curves are created and stored separately for the left and right channels and for the left and right ears, respectively, in such a way that certain frequency ranges are raised or lowered in accordance with the hearing impairment in order to compensate for hearing losses. The individual filter curves are determined by listening tests and then read into the memory 8 via the interface 11.

Via the microprocessor 7, depending on the signal of the clock 10, the CODEC circuit 13 is continuously switched over in such a way that the audio signals for the left channel and the right channel are offset in time or processed and amplified on the loudspeakers in the time-multiplex method 3 and 4 reproduced are, so that despite the stereophonic recording, editing, amplification and reproduction of the sound signals and in particular also despite the individual processing of the signals of the right and left channel, a minimal circuit complexity and low power consumption are ensured, so that the audio amplifier is relatively small despite high quality and compact and thus can be designed to be optimally portable by the user.

Since the microphones 1 and 2 are provided on the headphones 3 and 4 with the earphones or on the carrying bracket there or on these earphones 3 and 4, the hearing amplifier 6 can be accommodated in a pocket of a piece of clothing, which also contributes to convenient use. The digital processing of the audio signals also makes it possible to effectively suppress acoustic feedback between the microphones 1 and 2 and the listeners 3 and 4.

The switching frequency with which the CODEC circuit 13 is periodically switched between the channels is well above the audible frequency range and is, for example, approximately 24 to 25 kHz.

By using a single CODEC circuit 13 for both microphones 1 and 2 and both loudspeakers 3 and 4, a simplified layout for the printed circuit board of the hearing amplifier 6 also results in a reliable and trouble-free operation, since all channels are each provided by the control signals supplied by the microprocessor 7 are forcibly switched in the required manner.

In FIG. 2, 19 generally designates an audiometry device for self-audiometry, ie with this device the user is able to perform an own audiometry, ie an individual adaptation, on the basis of acoustic signals of different frequencies reproduced in the listeners 3 and 4 the transfer or filter curves as well as an individual Make dynamic adjustments for the left and right canal or for the left and right ear separately. In the embodiment shown, the audiometric device 19 has a control circuit 20, a speech memory 21, a generator 22 for the test frequencies and a data memory 23. The device 19 can be activated via the input 12 or via a button. The user then first receives, for example, some information and explanations for carrying out the self-audiometry from the voice memory 21. Furthermore, explanations and / or instructions are given to the user during the audiometry, which are transmitted via the earphones 3 and 4, respectively.

For the actual audiometry, the control circuit 20 causes the audio frequency generator 22 to emit test frequencies in the listening area, specifically a test frequency in a test phase with, for example, a continuously or step-wise increasing amplitude. As soon as the user has the desired auditory impression, he confirms this by pressing input 12 accordingly. The corresponding amplitude or dynamic value is stored in the data memory 23.

After the end of each test phase there is another test phase with a different tone frequency and again e.g. with increasing amplitude over time until the number of possible test phases is reached. The corresponding value of the amplitude or dynamics of the audio frequency is stored in the memory 23 for each test phase.

The number of test phases and thus the number of sound frequencies and their frequency are fixed, for example, but can also be varied according to certain criteria, depending on the measurement result.

The audiometry is independent for the left and right channels. At the latest after the end of the audiometry, the individual pass curves for the left and right channels are created from the data stored in the memory 23 by the microprocessor 7 and stored in the memory 8.

The advantage of the audiometric device 19 is that each user is able to determine his individual filter or transmission curves for storage in the memory 8, so it is not necessary to have these individual filter or transmission curves determined outside the home and then read into the memory 8 via the interface 1 1.

Another advantage of the audiometric device 19 is that the user can adapt the device at any time immediately and individually with regard to the transmission functions or dynamics to the existing environment in order to enable optimal hearing.

24 in FIG. 2 also designates a display device controlled by the microprocessor 7, on which the user also receives visual information, for example if the result of the self-audiometry which differs greatly from the norm indicates that the search for a specialist, for example, a doctor would be appropriate. In the simplest case, the display device 24 consists of at least one lamp, but can also be a display.

In the illustration in FIG. 2, the individual functions of the audiometric device 19 are shown as separate blocks 20-23. It goes without saying that these functions can also be taken over by other elements, for example by the microprocessor 7 with a corresponding design of the program stored in the memory 9.

FIG. 3 shows, as a further embodiment, a device G2 which is intended for connection to an audio device, for example to hi-fi audio systems or to television sets is. The device shown in FIG. 3 therefore differs from the device G1 of FIG. 2 essentially in that connections 25 and 26 are provided instead of the microphones 1 and 2, specifically for connection to the audio output of the respective audio device, namely the connection 25 for the left channel and the connection 26 for the right channel, the input amplifiers 15 being of course adapted to the signal levels occurring in this application.

Instead of the listeners 3 and 4, infrared transmission diodes 27 (for the left channel) and 28 (for the right channel) are provided on a transmitter 29 controlled by the CODEC circuit. The two infrared transmitter diodes 27 and 28 each deliver an audio signal modulated on a different carrier for the left channel and the right channel.

30 designates a receiving device which has two receiving diodes 31 (for the left channel) and 32 (for the right channel), two demodulators 33, the output amplifiers 16 and the two earphones 3 and 4, with one preferably not also on the receiving device 30 volume control shown is provided. While the device G2 is arranged in a stationary manner, the receiver 30 is designed to be portable, in such a way that it is carried by the user.

Apart from these differences, the device G2 corresponds to the device G1 in its general function, in FIG. 3 also those elements which correspond in function to the elements of the device G 1 are designated with the same reference numerals as in FIG. 2.

The device G2 allows, in the same way as described above for the device G1, an individual dynamic adaptation and individual adaptation of the filter or pass curves or transfer function to the respective user and also individually for the left and right channel or for the left and right Ear. The device G2 thus also enables people with limited hearing or hearing impairments to participate in voice and / or music transmissions in an optimal manner.

The peculiarity of the device G2 also consists in the fact that the audio signals modified by individual adaptation are transmitted over the transmission path formed between the transmitter diodes 27 and 28 and the receive diodes 31 and 32, so that the greater complexity in terms of circuitry is also present in the stationary device G2 , while the receiver 30 can be made very small and handy and thus in particular also convenient and inconspicuously portable, and in spite of a stereophonic, high-quality transmission.

A special feature of the device G2 is that the transmission of the audio signals via the transmission path formed between the infrared transmit diodes 27 and 28 and the infrared receive diodes 31 and 32 takes place in an analog manner, i.e. by analog modulated carrier frequencies, so that only simple demodulators are necessary in the receiving device 30, which also contributes to simplification and compact design and to a reduction in the power consumption of the receiving devices 30.

With the device G1, the data determined during the audiometry and / or the transmission functions or pass-through or filter curves created therefrom can also be read out via the interface 11, so that the device can even be used by a person skilled in the art of audiometry.

Instead of the connections 25 and 26, light detectors or an infrared light receiver device having such detectors can also be provided, such as are suitable, for example, for coupling to infrared outputs in audio devices. The invention has been described above using exemplary embodiments. It goes without saying that changes and modifications are possible without departing from the inventive idea on which the invention is based.

Reference list

, 2 microphone, 4 speakers

management

Hearing amplifier

Microprocessor, 9 memories

Clock

interface

input

CODEC circuit

Amplifier circuit

Input amplifier

Output amplifier

Power supply

DC / DC converter

Audiometric device

Control circuit

Voice mail

Tone generator

Data storage

Display device, 26 connection, 28 infrared transmitter diode

Infrared transmitter

Infrared receiver, 32 1 infrared receiver diode ńemodulator

Claims

claims

1 . Hearing aid with at least one electrical hearing amplifier (6, 6 ') for amplifying an audio input signal which is forwarded to a receiver arrangement (3, 4) over a transmission link, the hearing amplifier (6, 6') having at least one analog-digital converter for converting the analog audio input signals into a digital signal, digital means for signal processing of the digital signal to achieve a predetermined characteristic curve and / or transfer function for the hearing amplifier (6, 6 ') that optimally compensates for the hearing damage of the respective user, and at least one digital signal Analog converter for converting the processed or modified digital signal back into an analog audio signal fed to the receiver arrangement (3, 4), characterized in that the hearing amplifier (6, 6 ') has two channels for one receiver (3, 4) each. for stereophonic transmission, and that the digital means for both channels is an individual duel signal processing according to a transfer function stored individually in the memory (8) for the left and right ear of the user.

2. Hearing aid according to claim 1, characterized in that each channel of the hearing amplifier (6, 6 ') is assigned at least one microphone (1, 2) which supplies the analog audio input signal.

3. Hearing aid according to claim 1 or 2, characterized in that the transmission path between the hearing aid (6) and the receiver arrangement (3, 4) is formed by a multi-core electrical cable.

4. Hearing aid according to claim 1 or 2, characterized in that the transmission link is a wireless transmission link, preferably an infrared Transmission path (27, 28; 31, 32).

5. Hearing aid according to one of claims 1 to 4, characterized in that in the memory (8) individual transmission curves or functions and / or individual dynamic curves or functions are stored.

6. Hearing aid according to one of claims 1-5, characterized in that in addition to the individual transmission curves, further standardized transmission curves are stored in the memory (8), which can be superimposed on the individual transmission curves, for example to take into account special environmental conditions.

7. Hearing aid according to claim 6, characterized in that the further transmission curves have a high-pass or low-pass or bandpass character.

8. Hearing aid according to one of claims 1-7, characterized in that the processing of the Adio signals of the two channels by a common digital device (7), preferably by a common digital device (7) with a CODEC circuit (13) in the time-division multiplex process.

9. Hearing aid according to one of claims 1-8, characterized in that the two earphones (3, 4) are part of a headphone or an attachable to a user's head assembly.

10. Hearing aid according to one of claims 1-9, characterized in that the two microphones (1, 2) are each provided on a receiver or in the vicinity of a receiver and / or on the receiver arrangement. 1 1.Hearing aid according to one of claims 1-10, characterized in that the analog-digital converter and the digital-analog converter are part of a common CODEC circuit (13) which is controlled by the microprocessor (7).

12. Hearing aid according to one of claims 1 - 1 1, characterized in that for

Voltage or power supply a power supply and / or a power supply (1 7) formed by at least one battery, preferably a rechargeable battery, is provided such that the analog circuits, in particular input and output amplifiers (15, 16) directly from the power supply (1 7) are supplied, and that digital circuits are connected to the power supply via a DC / DC converter (18).

13. Hearing aid according to one of claims 1-12, characterized by an interface (1 1) for reading in and / or reading out the data defining the special transmission curves in the memory (8).

14. Hearing aid according to one of claims 1-13, characterized by connections (25, 26) for connecting the hearing amplifier to the stereo output of entertainment devices, for example audio devices and / or televisions.

1 5. Hearing aid according to one of claims 1-14, characterized in that the receiver arrangement (3, 4) is part of a receiver (30) separate from the hearing amplifier (6 '), the transmission path between the hearing amplifier (6') and the receiving device (30) is formed and the modified signals are transmitted via this transmission path.

16. Hearing aid according to claim 15, characterized in that on the

Transmission path the modified signals in analog form or in form at least one analog modulated carrier signal are transmitted.

7. Hearing aid according to one of claims 1-16, characterized by an audiometric device (19) for self-audiometry.