EP1416764B1 - Method of setting parameters of a hearing aid and device for carrying out this method - Google Patents

Description

The present invention relates to a method for adjusting a hearing aid and to an apparatus for carrying out the method.

When changing from an existing to a new hearing aid, the experienced hearing aid user will also be treated like a first adaptation, i. a tone audiogram is used as the basis for the new hearing aid setting. Experience has shown, however, that especially with long-term hearing aid users, the actual desired setting of the hearing aid parameters - such as gain, compression, limitation, knee point or time constant - often deviates very much from the audiogram-based preset. When changing to a new hearing aid therefore rather a setting is desired, which is as similar as possible to one's own hearing aid. In particular in the case of the severely deaf, the need for amplification may deviate up to 20 dB from the target gain precalculated according to the audiogram. Here, a different basis of presetting than the audiogram alone is desirable.

Experience reports have shown that using a preset based on the old hearing aid setting is a very effective and successful one Fitting method, which is often superior to audiogram-based fitting.

Currently, no simple automatic procedure is known for this, which supports this type of presetting a hearing aid. Although one possibility is to measure the own old hearing aid in a specially provided measuring device at different input levels. The measured values must then be manually transferred to the fitting software of the new hearing aid, which is tedious and error-prone. Such measuring devices are made, for example U.S. 5,703,797 and from US-2002/0176584 known.

The present invention is therefore based on the object of specifying a simple and efficient method for setting a first hearing device based on settings of a second hearing device.

This object is achieved by the features specified in claim 1. Advantageous embodiments of the invention and an apparatus for carrying out the method are specified in further claims.

The invention has the following advantages: in that a predefined measuring signal is applied to a microphone of a hearing device which is adapted to a specific hearing aid wearer and in that an acoustic signal generated by a listener of this hearing aid is recorded and recorded in a hearing aid to be adjusted, wherein settings in a new hearing aid due to results of the Evaluation are made in the evaluation, a particularly suitable method for Erstanpassung the new hearing aid is created. The method according to the invention very quickly leads to a spontaneous acceptance of the newly set hearing device in the case of the hearing aid wearer and considerably reduces the fitting outlay compared with the methods used today. In addition, the acoustician needs less time for initial adaptation.

In the following the invention with reference to drawings, in which possible embodiments are shown, further explained.

Fig. 1

eine erfindungsgemässe Vorrichtung mit einem ersten, anzupassenden Hörgerät, einem zweiten, angepassten Hörgerät sowie einer Kontrolleinheit und

Fig. 2

eine abgewandelte Ausführungsform gegenüber derjenigen gemäss Fig. 1.

Showing:

Fig. 1

a device according to the invention with a first, to be adapted hearing aid, a second, adapted hearing aid and a control unit and

Fig. 2

a modified embodiment compared to those according to Fig. 1 ,

In Fig. 1 is a control unit 1, an existing hearing aid 2, which is set to a specific hearing aid wearer and is referred to below as a second hearing aid, and another hearing aid 3 shown, which is operatively connected to the second hearing aid 2 and is referred to below as the first hearing aid. In the control unit 1, which for example a commercially available PC (personal computer), consisting essentially of input / output unit and arithmetic unit, a fitting program (fitting software program) is processed, which allows the acoustician as simple and quick hearing aid adaptation to a specific hearing aid wearer. For this purpose, the control unit 1 on the one hand with a loudspeaker 6, by means of which acoustic test signals 20 can be generated, on the other hand connected via the connecting line 7 with the first hearing aid 3, which is equipped as usual with a microphone 3a and a receiver 3b. Furthermore, the first hearing device 3 has an audio input 10, via which an audio signal can be supplied.

The second hearing device 2 likewise has a microphone 2a and a receiver 2b, the latter being completely covered by a coupling element 5, so that a closed cavity is created. In this cavity also a measuring microphone 4 is arranged, whose signal is applied to the audio input 10 of the first hearing aid 3. A known coupling element for use in the present invention is described, for example, in Phonak Focus No. 20 entitled " The Desired Sensation Level (DSL) Method for Hearing Aid Fitting Infants and Children "(Richard C. Seewald, 1995 ). An identical publication is included in the publication titled "DSL 4.0 Handbook" by the same author.

As described above, the object of the present invention is to provide a hearing aid setting for to find the first hearing aid 3, which is as similar as possible to that of the second hearing aid 2. Thus, a high spontaneous acceptance when first wearing the first hearing aid 3 can be achieved. This first hearing aid setting is then ideally suited as a starting point for further fine adjustments and optimizations of the hearing aid settings.

The process according to the invention is described below:

In a first embodiment of the invention, the first hearing device 3 can be brought into a so-called measurement mode at the beginning of the adaptation, in which the transmission properties of the second hearing device 2 are analyzed and transmitted to the control unit 1. The adaptation software executed in the control unit 1 transforms the information obtained into a parameter set which can be understood by the first hearing device 3. Incidentally, the entire sequence of the setting of the first hearing device 3 is controlled or monitored by the fitting software. Likewise, any instructions or error messages on the control unit 1 are displayed to the acoustician.

In the control unit 1, for example, a so-called sound card is used to drive the loudspeaker 6, as used in conventional personal computers.

As has already been mentioned, the second hearing device 2 is coupled to the coupling element 5 having a known transmission characteristic, which contains the measuring microphone 4, preferably in the form of a probe microphone (corresponding to IEC Standard 126 2cc coupler HA-1 for ITE (In -The-Ear) hearing aids or HA-2 for BTE (Behind-the-Ear) hearing aids). The signal of the measuring microphone 4 is fed via the audio input 10 into the first hearing device 3 and analyzed therein. For this purpose, a filter bank which is present in the first hearing device 3 and which is used for signal processing during normal operation of the hearing aid can be used. At the same time, the microphone 3a of the first hearing device 3 picks up the sound of the loudspeaker 6 and serves as a reference microphone for determining the volume or sound level and for controlling the sound presentation via the control unit 1. This also creates the possibility that a calibration of the first hearing aid 3 can be made. The two hearing aids 2 and 3 should be close together so that the same sound field is present. Incidentally, the adaptation of the first hearing device 3 can be made optimally if no acoustic interference signals can be picked up by the microphones 2a and 3a. Advantageously, therefore, the whole arrangement is located in a sound-deadened room. In addition, it is provided that noise is detected by a corresponding algorithm in the control unit 1, whereby erroneous measured values can be eliminated (artefact rejection).

This arrangement is now presented with different acoustic test signals 20, such as white noise at different levels. As test signals but also sinusoidal or sinusoidal signals, wobble tones, natural language or music are conceivable. By recording acoustic signals 21 which are emitted by the receiver 2b into the coupling element 5 and recorded by the measuring microphone 4, the transmission function of the second hearing device 2 in the first hearing device 3 can be determined. Further, transient test signals 20 (e.g., level jumps) may be used to determine the temporal behavior, such as the time constant of the compression.

Based on these measurement data, the first hearing device 3 can now be set so that the transfer functions of the first and second hearing devices 3 and 2 become as similar as possible.

It is pointed out that the second hearing device 2 to be measured can be any hearing device. The "new" first hearing device 3 has a frequency resolution and an audio input 10, to which a simple coupling of the measuring microphone 4 is possible.

The measurement is carried out in as quiet a room as possible - which incidentally is also necessary for the measurement of the feedback threshold of a hearing device or the hearing threshold of the hearing impaired person. The conditions at the space required for the measurements in an acoustician are therefore already readily met.

The second hearing aid 2 is connected to the coupling element 5, which is for example a so-called 2cc coupler. The 2cc coupler is defined according to standard IEC 126 (see above literature by Richard C. Seewald), although other couplers can be used as long as a defined volume with appropriate coupling is present. A conversion to standardized 2cc values is then possible at any time. Instead of a standard microphone, an adapter with a channel for a probe tube is inserted into the coupling element 5. The actual measuring microphone 5 forms, for example, a RECD (Real-Ear-to-Coupler Difference) - direct audio shoe (see again IEC 126 and the literature cited by Richard C. Seewald), whose probe tube protrudes into the 2cc volume via the adapter.

In a preferred embodiment of the invention, the first and the second hearing device 2 and 3 are placed on a smooth surface so that the microphones 2a and 3a of the two hearing aids 2 and 3 are close to each other. The loudspeaker 6 used for sonication with test signals 20 is, for example, approximately 50 cm away from the microphones 2a and 3a.

As already mentioned, for the measurement via the loudspeaker 6, for example, stationary or speech-modulated white noise or ICRA noise are reproduced. A definition of the ICRA noise is, for example, in the article by WA Dreschler, H. Verschuure, C. Ludvigsen and S. Westermann entitled " ICRA noises: Artificial noise signals with speech-like spectral and temporal properties for hearing aid assessment "(Audiology, Vol. 40, No. 3, May-June, 2001, pp. 148-157 ) contain. The test signals 20 are given to the loudspeaker 6 via the sound card of the personal computer operating as the control unit 1.

To calibrate the first hearing device 3, a stationary white noise is reproduced as a test signal 20 via the loudspeaker 6. Input level averaging means present in the first hearing device 3 are read out and, if appropriate, the reproduction is corrected spectrally and in terms of level, provided that no excessive changes are necessary. Otherwise, the acoustician is informed that the speaker quality is insufficient. If a spectral correction via the control unit 1 is not possible, the method can nevertheless be carried out. However, the informative value of the results is somewhat limited.

Before and after calibration of the playback levels, the spectral background level in the test room is determined using the same method. If it is so high that a meaningful measurement is not possible, the acoustician, for example via the control unit 1, informed accordingly.

A first measurement consists for example in that a modulated test noise (see above) is reproduced via the loudspeaker 6 in succession as the acoustic test signal 20 with the levels 50, 65 and 80 dB. In the coupling element 5, the reproduction of the second hearing device 2 to be measured is detected by means of the measuring microphone 4. This reproduction is representative of the reproduction of modulated signals, e.g. Language.

A second measurement consists, for example, in that over the loudspeaker 6 an unmodulated test noise (see above) is reproduced as an acoustic test signal 20 at 65 dB. At the coupling element 5, the reproduction of the second hearing device 2 to be measured is detected. This reproduction is representative of stationary sound reproduction. The amount of noise reduction (noise canceling) is determined from the reproduction difference between the first and the second measurement.

For example, if necessary, a third measurement may be that an unmodulated noise is reproduced via the loudspeaker 6 with a level jump of 25 dB in the middle of the signal (first 55 dB, then 80 dB and then 55 dB). From the response detected in the coupling element 5, the order of magnitude of the entry and release times can be determined.

In an alternative third measurement, loudspeaker 6 becomes real speech or equivalent modulated test noise (see above) at 65 dB level output as acoustic test signal 20. The amplitude distribution of the recorded signal is evaluated and from this the effective dynamic compression and the time constants of the compression can be determined, which will be explained further below.

The effective dynamic compression of a signal is determined as follows: First, one determines the dynamics of the input signal of a typical modulated signal, such as speech at 65 dB SPL. It results e.g. from the difference between the 10th and 95th percentile of the amplitude distribution. Now, the signal picked up by the microphone 2a and processed in the second hearing aid 2 is analyzed in the same way. The ratio of the dynamic range determined above to the dynamic range now obtained indicates the effective compression ratio of the signal processing from the second hearing aid 2.

If, in addition, the same measurements are carried out with an unmodulated signal, the static compression ratio is obtained.

The time constants of the compression control can be determined on the other side as follows:

One calculates the modulation spectra of the signal processed by the second hearing aid 2 for a speech signal or a voice-like modulated signal as well as the same unprocessed signal. Since a dynamic compression control acts as a modulation high-pass filter, a difference of these two modulation spectra usually has a high-pass characteristic with a certain cut-off frequency. This cut-off frequency of the modulation high-pass is a direct measure of the control times of the compression.

The results of the first measurement are used to set the input / output functions of the different channels. The difference between the second and the first measurement is used to adjust the amount of noise cancellation (noise canceling). If the time constants of the gain control belong to the fitting parameters, the third measurement can be used to set the settling times.

For hearing aids in which various hearing programs can be selected, the individual programs are activated one after the other in the second hearing device 2 to be measured and measured with the described method.

The volume adjuster is preferably placed in the position to be measured, second hearing aid 2 in that position, which is suitable for listening mittellauter sound. This means a customer attitude that is suitable for comfortable listening in a quiet environment. For digital hearing aids is this is usually the setting directly after switching on the hearing aid.

If the limit of the second hearing device 2 to be measured is also to be recorded (setting of a limiter), the second hearing device 2 must additionally be sonicated with 90 dB. Incidentally, the method described is used. A 90 dB performance is usually uncomfortable for the acoustician and the hearing aid user.

Fig. 2 shows a further embodiment of the invention, wherein these from the in Fig. 1 shown embodiment differs only in that the acoustic test signal 20 is generated by means of the first hearing aid 3. For this purpose, a further coupling element 50 between the second and the first hearing device 2 or 3 is necessary. The speaker 6 is required in this embodiment only for the mentioned calibration. The main processing of the signals is carried out - under the guidance of the control unit 1 - mainly in the first hearing aid 3. In addition, the various measurement methods that are associated with the in Fig. 1 illustrated embodiment, according to the embodiment according to Fig. 2 usable and therefore need no further explanation.

Claims (15)

1. A method for adjusting a first hearing device (3) based on adjustments of a second hearing device (2), the method comprising the steps of:

   - converting an acoustic test signal (20) into an electric test signal by a microphone (2a) of the second hearing device (2);

   - converting an acoustic signal (21) generated by a receiver (2a) of the second hearing device (2) into an electrical signal;

   - analyzing the electrical signal in said first hearing device (3), and

   - adjusting the first hearing device (3) based on results obtained by the analysis performed in the first hearing device.
2. The method of claim 1, wherein the acoustic test signal (20) is generated in a control unit (1) provided outside the hearing devices (2,3).
3. The method of claim 1, wherein the acoustic test signal (20) is generated in the first hearing device (3).
4. The method of any of claims 1 to 3, wherein the step of analyzing the electrical signal (21) takes place in a control unit (1) provided outside the hearing devices (2, 3).
5. The method of one of claims 1 to 4, comprising the step of simultaneously feeding the acoustic test signal (20) to a microphone (3a) of the first hearing device (3) for its calibration.
6. The method of one of the preceding claims, wherein a stationary or a speech-modulated noise is used as said acoustic test signal (20).
7. The method of one of claims 1 to 4, wherein an unmodulated noise with a level step of preferably 25 dB is used as acoustic test signal (20).
8. The method of one of the preceding claims, wherein the adjusting of the first hearing device is carried out in all available hearing programs.
9. The method of one of the preceding claims, comprising setting a sound level between 40 and 90 dB SPL for the acoustic test signal.
10. An apparatus for carrying out the method of one of claims 1 to 9, comprising

    - a first hearing device (3) with a microphone (3a) and a receiver (3b);

    - a second hearing device (2) with a microphone (2a) and a receiver (2b), whereby said first hearing aid (3) can be set based on settings of said second hearing aid (2);

    - means (1,6,3,3b) for feeding the microphone (2a) of said second hearing aid (2) with an acoustic test signal (20),

    - means (4,5) for transforming an acoustic signal (21) produced by the receiver (2b) of said second hearing aid (2) into an electric signal, and

    - means for feeding said first hearing aid (3) with said electric signal,

    whereas means for analyzing said electrical signal are provided in said first hearing aid (3) and said first hearing aid (3) is constructed such that settings can be made on the basis of results of said analysis.
11. The apparatus of claim 10, wherein a control unit (1) operatively connected with the first hearing device (3) is arranged outside said hearing aids (2,3).
12. The apparatus of claim 11, wherein a loudspeaker (6) is operatively connected to the control unit (1).
13. The apparatus of claim 10 or 11, wherein the acoustic test signal (20) is furthermore fed to a microphone (3a) of said first hearing aid (3).
14. The apparatus of one or more of claims 10 to 12, comprising a measurement microphone (4) for recording the acoustical signal (21) produced by the receiver (2b) of the second hearing aid (2), the measurement microphone (4) being operatively connected to the first hearing device (3).
15. The apparatus of one or several of claims 10 to 14, wherein an acoustic signal produced by loudspeaker (6) is fed exclusively to the microphone (3a) of hearing device (3).

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