EP0788290B1 - Programmable hearing aid - Google Patents

Description

The invention relates to a programmable hearing aid with a in its transmission properties between microphone and Handset adjustable to different transmission characteristics Amplifier and transmission part, being in the signal path several between the microphone (2) and the handset (3) Tapping points (5) for tapping signals (6, 6 ') are available are.

In a hearing aid known from EP-B-0 064 042, in a hearing aid memory eight parameter sets for different Transmission characteristics for different environmental situations stored. By operating a switch can the different parameter sets for the eight stored programs can be called up. A control unit controls one switched on between microphone and handset Signal processor, which is then a first, for an intended Certain transmission function. Via the switch, however, the stored signal transmission programs can only be accessed one after the other until, in the opinion of the hearing aid wearer, the one just given Suitable transfer function found in the surrounding situation is. Accordingly, in the known programmable hearing aid generally several user-selectable parameter sets, so-called listening situations. Everyone of these parameter sets represents the sensibly coordinated Setting of all signal processing parameters for represents a certain acoustic situation, e.g. at rest, i.e. with no annoying background noise or conversation low-frequency noise, etc. The hearing aid wearer chooses the desired situation by pressing a button on the hearing aid.

EP-A-0 674 464 relates to a programmable hearing aid Fuzzy logic controller. This hearing aid has a control system being for automatic switching and adjustment to the respective environmental situation and the amplifier and Transmission controller assigned controller that is dependent of the particular surrounding situation Input variables a selection of those in the data carrier of the hearing aid stored parameter sets or of parameters for Change in transmission characteristics of the hearing aid performs.

For an automatic or largely automatic, from input or measurement signals dependent adaptation of a programmable Hearing aid is used in the European patent application EP-A-0 712 263 the signal path from the microphone to the listener sibling neural structure suggested of a disk is assigned, whereby from the signal path from a or more tapping points tapped and one Module for signal processing are supplied and where the processed signals can be fed to the neural structure, which generates control signals to select from in one parameters stored in the data path associated with the signal path of the amplifier and transmission part or to change the amplifier and transmission characteristics to the Amplifier and transmission part are deliverable.

The proposals according to EP-A-0 674 464 and EP-A-0 712 263 concern the determination of hearing programs and signal processing parameters using fuzzy logic or using a neural structure, being in both cases from an evaluation of the input signal (s) in the time domain and the realization of the fuzzy logic or the neural Structure in analog circuitry is specified.

EP-A-0 681 411 includes a programmable hearing aid one in its transmission properties between microphone and handset adjustable to different transmission characteristics Amplifier and transmission part known, wherein from the signal path between the microphone and the handset tapped at one or more tapping points and are fed to a module for generating control signals to control the signal processing in the hearing aid.

The object of the invention is a hearing aid of the type mentioned Kind of creating a largely automatic Selection of a respective hearing program or the automatic one Setting individual signal processing parameters by evaluation of the acoustic signal arriving in the hearing aid, with special possibilities of signal evaluation should be usable.

According to the invention this object is achieved in that a Module for selecting one or more tap signals available and is a module for transforming the selected one or more Tapping signals from the time domain to the frequency domain is available and a module for signal evaluation in the Frequency range transferred signals available in the frequency range is, the module for signal evaluation in the Frequency range transferred signals in the frequency range control signals generated to choose from in a the signal path assigned data storage parameters of the Amplifier and transmission part or to change the Amplifier and transmission characteristics to the amplifier and transfer part are dispensable.

In the hearing aid according to the invention there is a signal evaluation provided that the incoming acoustic signal first is subjected to a spectral analysis and the actual Analysis then takes place in the frequency domain. The algorithms and rule sets for the analysis of the pre-processed Signals should be given or programmed as flexibly as possible his. Here, the digital circuit technology offers Realization special advantages. For the logical implementation the algorithms and rule sets are available alternatively mathematical calculation rules, fuzzy logic and neural structures. According to the invention is a better one Adaptation of the signal processing to the hearing damage continuous signal-dependent setting of the signal processing parameters possible. At the same time, the hearing aid wearer relieved of this, carry out a hearing program switch yourself to have to.

Advantageous embodiments of the invention are due to the claims characterized.

Further advantages and details of the invention are set out below based on the embodiments shown in the figures explained in more detail.

Figur 1 ein Blockschaltbild eines erfindungsgemäßen Hörgerätes mit einem Verstärker- und Übertragungsteil für eine analoge Signalverarbeitung,

Figur 2 ein Blockschaltbild eines erfindungsgemäßen Hörgerätes mit einem Verstärker- und Übertragungsteil für eine digitale Signalverarbeitung,

Figur 3 ein Blockschaltbild eines erfindungsgemäßen Hörgerätes mit einem Verstärker- und Übertragungsteil für eine digitale Signalverarbeitung, wobei das Hörgerät-Modul zur Signalauswertung im Frequenzbereich mit einem Speicher im Datenaustausch steht,

Figuren 4 bis 6 Blockschaltbilder für mögliche Hörgerät-Module zur Signalauswertung im Frequenzbereich und zur Bestimmung des - in Abhängigkeit vom Hörgerät empfangenen akustischen Signals - jeweils zu aktivierenden Hörprogramms,

Figuren 7 bis 9 Blockschaltbilder für mögliche Hörgerät-Module zur Signalauswertung im Frequenzbereich und zur Bestimmung einzelner Signalverarbeitungsparameter, in Abhängigkeit des vom Hörgerät empfangenen akustischen Signals.

Show it:

FIG. 1 shows a block diagram of a hearing aid according to the invention with an amplifier and transmission part for analog signal processing,

FIG. 2 shows a block diagram of a hearing device according to the invention with an amplifier and transmission part for digital signal processing,

FIG. 3 shows a block diagram of a hearing aid according to the invention with an amplifier and transmission part for digital signal processing, the hearing aid module being in data exchange with a memory for signal evaluation in the frequency range,

FIGS. 4 to 6 block diagrams for possible hearing aid modules for signal evaluation in the frequency range and for determining the acoustic program to be activated, depending on the hearing aid received,

Figures 7 to 9 block diagrams for possible hearing aid modules for signal evaluation in the frequency domain and for determining individual signal processing parameters, depending on the acoustic signal received by the hearing aid.

The hearing aid according to the invention shown schematically in FIG. 1 1 records 2 sound signals via a microphone. This Acoustic information is converted into electrical signals in the microphone implemented. After signal processing in a gain and transmission part 4 becomes the electrical signal fed to a receiver 3 as an output converter. With the hearing aid 1 is an analog signal processing in the amplifier and transmission part 4 provided. In doing so, the Signal path from one or more tapping points 5 analog Signals 6 tapped.

A module 12 for selecting the tap signal 13 determines from which point in the signal path the signal is tapped and it then leads to an analog / digital converter 14. there it can either make this selection according to its own, in it implemented algorithm or according to an external control signal 18 meet. The digitized in the analog / digital converter 14 Signal 15 is then a module 7 for transformation of the signal or signals 15 from the time domain to the frequency domain fed. The data transformed in module 7 or signals 8 are then generated by a module 9 for signal evaluation processed in the frequency domain. Run here the essential signal analysis and signal detection algorithms from, when determining the new signal processing parameters also system information of the hearing aid in the Selection decision can be included; e.g. about the position of controls or the respective battery charge level and by means 16 for detecting system states and by its output signals 17. Here are the control signals 10 generated in module 9 for selection of data memories stored in a signal path Parameters of the amplifier and transmission part or to change the amplifier and transmission characteristics deliverable to the amplifier and transmission part 4. According to FIG. 1, the module 12 can be used to select one or more Tapping signals 13 control signals 18 of a control module 19 feedable, whereby the selection of the tap signals can be influenced is.

If according to the embodiment of Figure 2 in a digital Hearing aid 1 'in the amplifier and transmission part 4 'digital signal processing takes place in the signal path, does not become a separate analog / digital converter for signal analysis needed. Instead, the already digital signal 6 'tapped from the signal path and for signal analysis be processed further. The tapped digital signal 6 ' is used after module 12 to select one or more tap signals as a digital tap signal 13 'to module 7 Transformation of the signal fed into the frequency domain. The further signal analysis can proceed as described above.

The transformation of the tapped signal into the Frequency range happens e.g. according to the known methods the discrete Fourier transform or the Fast Fourier Transformation. As a result of the transformation, the Amplitude and phase values of the signal on a selectable Number of support points available.

Together with the circuit diagrams of Figures 3 to 6 is in following the determination of the hearing program by signal evaluation described in the frequency domain, namely the determination the hearing program through a mathematical calculation rule, via a fuzzy logic set of rules or with the help of a neural structure. The acoustic first Environmental situation can be analyzed and classified. there will generally result that they are a mixture of the hearing situations on which the hearing programs are based (= corner hearing situations) equivalent. Accordingly, it must be decided which of the saved hearing programs is activated or how from the stored hearing programs a suitable mean hearing program should be obtained.

According to an advantageous embodiment according to Figure 3 stands the module 9 for signal evaluation in the frequency domain with a Memory 20 in data exchange, module 9 signals 21 outputs to the memory 20 and causes the memory to certain data 22 to the amplifier and transmission part 4 to deliver or take data 23 from memory 20, processed and as control signals 10 to the amplifier and transmission part 4 issues.

To determine the listening situation using mathematical functions has the module 9 for signal evaluation in the frequency domain, As FIG. 4 shows, a component 24 for normalizing the Amplitude values, a component 25 for the formation of frequency-related Characteristics, a component 26 for the formation of temporal parameters, a component 27 for the formation of Similarity measures and a component 28 for determination of the hearing program to be activated.

normalization:

Because the situation analysis is independent of the absolute Loudness of the signal to be examined should take place in first processing step a normalization of the amplitude values instead of. One way to do this is to determine the factor by which the largest amplitude value is multiplied must assume a predetermined maximum value. Subsequently all amplitude values are multiplied by this factor.

Formation of frequency-related parameters:

Since the amplitude values alone are not used for further evaluation, but parameters that describe their relationship to each other, needed, they must be formed. Examples for this are:

Sum of amplitude values. Differences in amplitude values.

Mean values of amplitude values. These can also be weighted.
Power of the signal in certain frequency ranges.
Average rise / fall of the amplitude values in certain frequency ranges.

The exact calculation of these intermediate sizes required in each case is part of the entire analysis algorithm.

Creation of time parameters:

Since, in addition to the variables available up to now, each of which is valid for a time interval of the Fourier transformation, their temporal course is also important for the signal analysis, additional temporal parameters are then determined from the previous parameters and amplitude values.
Examples for this are:

Totals, sometimes also weighted, from parameters to different ones Times.

Differences, sometimes also weighted, from parameters to different ones Times.

Average values of parameters at different times.

Average increase / decrease in parameters within a certain time interval.

Calculation of similarity measures:

The next step is to determine how similar the current one is acoustic situation to the given listening situations (= Corner listening situations).

For this, the deviation of yours for each corner hearing situation Characteristic value set from the currently determined characteristic value set of acoustic environment determined. For example the absolute value for each situation comparison for each characteristic value the difference is determined and with a given Weighted factor. The sum of these weighted differences gives a measure of the similarity of the current situation with the respective corner listening situation. The weighting of the differences leads to deviations of different Characteristic values depending on their meaning more or less in the Calculate the similarity measure.

Kennwertsatz von Eck-Hörsituation 1: W1 = ( w11, w12, w13)

Kennwertsatz von Eck-Hörsituation 2: W2 = ( w21, w22, w23)

Kennwertsatz von Eck-Hörsituation 3: W3 = ( w31, w32, w33)

Kennwertsatz der aktuellen Hörsituation: WA = (wA1, wA2, wA3)

Berechnung der Ähnlichkeitsmaße: Ähnlichkeitsmaß 1: S1 = g1 * | w11 wA1 | + g2 * | w12 -wA2| + g3 * | w13 - wA3 | Ähnlichkeitsmaß 2: S2 = g1 * | w21 - wA1 | + g2 * | w22 -wA2| + g3 * | w23 - wA3 | Ähnlichkeitsmaß 3: S3 = g1 * | w31 - wA1 | + g2 * | w32 -wA2| + g3 * | w33 - wA3 |

Hierbei bedeutet | ... | die mathematische Funktion der Betragsbildung und
g1, g2, g3 stellen die Gewichtungsfaktoren der einzelnen Kennwerte dar.This procedure can easily be described mathematically, as shown in the following example. 3 corner hearing situations with 3 characteristic values each are assumed.

Characteristic set of corner hearing situation 1: W1 = (w11, w12, w13)

Characteristic set of corner hearing situation 2: W2 = (w21, w22, w23)

Characteristic set of corner hearing situation 3: W3 = (w31, w32, w33)

Set of characteristic values of the current hearing situation: WA = (wA1, wA2, wA3)

Calculation of similarity measures: Similarity measure 1: S1 = g1 * | w11 wA1 | + g2 * | w12 -wA2 | + g3 * | w13 - wA3 | Similarity measure 2: S2 = g1 * | w21 - wA1 | + g2 * | w22 -wA2 | + g3 * | w23 - wA3 | Similarity measure 3: S3 = g1 * | w31 - wA1 | + g2 * | w32 -wA2 | + g3 * | w33 - wA3 |

Here, | means ... | the mathematical function of the amount formation and
g1, g2, g3 represent the weighting factors of the individual parameters.

Determination of the hearing program to be activated:

Now that there is a similarity measure for the current acoustic Situation with every corner hearing situation must be activated Hearing program can be determined. In the simplest case the hearing program is activated for which the similarity measure between the corresponding corner situation and the current one acoustic situation has the greatest value. This must however, a switching hysteresis can be provided in Borderline situations a constant switching between two Avoid hearing programs.

In addition to this simple solution, there is an option to do so activating hearing program from the stored hearing programs to be calculated in such a way that a for each parameter Mean value is formed of the individual similarity measures between current situation and corner situations.

For example, this could be done by having each parameter the corner situations with the corresponding measure of similarity is multiplied, these quantities are then added and then the value obtained by the sum of the similarity measures is divided. This would result for every parameter a kind of "interpolated average".

Hörprogramm 1: P1 = ( p11, p12, p13 )

Hörprogramm 2: P2 = ( p21, p22, p23 )

Hörprogramm 3: P3 = ( p31, p32, p33 )

This method can also be easily described mathematically, as shown in the following example. It is based on 3 hearing programs with 3 signal processing parameters each.

Hearing program 1: P1 = (p11, p12, p13)

Hearing program 2: P2 = (p21, p22, p23)

Hearing program 3: P3 = (p31, p32, p33)

Hearing program to be calculated: PN = (pN1, pN2, pN3) Calculation of the signal processing parameters of the hearing program to be set: pN1 = (p11 * S1) + (p21 * S2) + (p31 * S3) S1 + S2 + S3 pN2 = (p12 * S1) + (p22 * S2) + (p32 * S3) S1 + S2 + S3 pN3 = (p13 * S1) + (p23 * S2) + (p33 * S3) S1 + S2 + S3

It can be advantageous instead of a mathematical implementation the calculation of the similarity measures using Realize fuzzy logic. The advantages of fuzzy logic over have a closed mathematical approach in that even non-linear relationships are simply described and can be edited, e.g. at the edge of permissible value ranges can occur. Even each other partially contradicting values of input variables can processed meaningfully together. For this, how described above, also the steps of standardization, education of frequency-related parameters and formation of temporal Characteristics accomplished. To calculate the similarity measures but now the relevant amplitude values and parameters the steps of fuzzification, inference and defuzzification subjected. The result is also similarity measures available for every corner hearing situation their similarity to the current acoustic environment describe. The determination of the to be activated The hearing program then happens in the same way as above described.

To determine the listening situation using fuzzy logic is according to Figure 5 shows a module 9 for signal evaluation in the frequency domain provided, characterized by a component 24 for standardization of the amplitude values, a component 25 for formation of frequency-related parameters, a component 26 for formation of time parameters, a component 29 for fuzzification, a component 30 for inference formation, a Component 31 for defuzzification of the similarity measures and a component 28 for determining what is to be activated in each case Hearing program.

For the determination of the hearing situation via a neural The structure according to the invention is a module 9 for signal evaluation provided in the frequency domain, consisting of a Component 24 for normalizing the amplitude values, a component 25 for the formation of frequency-related parameters, one Component 26 for the formation of time parameters and a component 32 for realizing a neural structure to determine the hearing program to be activated. According to FIG. 6, the module 9 can send signals 21 to one Output memory 20, which then data signals 22 to the amplifier and transmission part 4 for determining the one to be activated in each case Supplies hearing programs.

It can be advantageous to determine the hearing program to use a neural structure because then it's possible is also empirically acquired "decision making knowledge to implement, even if this is not explicit can be formulated. As already described, likewise the steps of standardization, formation of frequency-related Parameters and formation of time parameters completed. The amplitude values and intermediate variables are now given to the inputs of a neural structure. Corresponding the transmission behavior defined in its structure then place those at its exits Values a code representing the hearing program to be activated selects. Another calculation of the hearing program to be activated, as in the embodiments of Figures 4 and 5 not necessary in this case.

Instead of a complete set of signal processing parameters (Hearing program) can also determine each parameter for to be determined. Referring to the circuit diagrams of FIGS. 7 to 9, the determination of the individual is shown below Signal processing parameters through signal evaluation in Frequency range described, by determining the Parameters via mathematical functions, via fuzzy logic or through a neural structure.

In order to determine the signal processing parameters according to a mathematical calculation rule, the amplitude values must also be normalized, as already described. The value is then calculated in a component 33 for determining the individual signal processing parameters for each parameter to be determined according to a formula, for example according to: G 2 (n) = [A 1 (n) + A 1 (n-1) * 0.5 + A 1 (n-2) * 0.2] * 0.3 + [A 2 (n) + A 2 (n-1) * 0.6 + A 2 (n-2) * 0.3] * 0.4 + [A 3 (n) + A 3 (n-1) * 0.6 + A 3 (n-2) * 0.4] * 0.5 + · · · [A 16 (n) + A 16 (n-1) * 0.5 + A 16 (n-2) * 0.2] * 0.3

G₂

den zu berechnenden Parameter, hier z.B. die Verstärkung im Kanal 2.

A_i(...)

den i-ten Amplitudenwert der Fourieranalyse.

(n), (n-1), ...

kennzeichnet, daß es sich um den jeweiligen Wert im Zeitintervall n, n-1, ... der Fourieranalyse handelt.

Here means:

G ₂

the parameter to be calculated, here for example the gain in channel 2.

A _i (...)

the i-th amplitude value of the Fourier analysis.

(n), (n-1), ...

indicates that it is the respective value in the time interval n, n-1, ... of the Fourier analysis.

It can be advantageous instead of using a mathematical rule the calculation of the signal processing parameters with Realize with the help of fuzzy logic. The benefits of fuzzy logic against a closed mathematical approach in that even non-linear relationships are simply described and can be edited, e.g. on the edge of permissible value ranges can occur. Even each other partially contradicting values of input variables can processed meaningfully together. This will also the steps of normalization 24, formation of frequency-related Parameters 25 and formation of time parameters 26 completed. But now to calculate the parameter values by means of the module components 34, 35, 36 the relevant ones Amplitude values and parameters in the steps of fuzzification, Subjected to inference and defuzzification. Stand as a result then the required parameter values are available.

Finally, it can be advantageous to determine the parameters to use a neural structure. It will possible, also empirically gained, learned decision knowledge to implement, even if this is not explicit can be formulated. For this purpose, as described, also the steps of standardization, formation of frequency-oriented Characteristics and formation of temporal characteristics accomplished. The amplitude values and intermediate variables are then in a module component 37 to the inputs of a neural Given structure. According to the structure of the structure Transmission behavior then put at its outputs the set values of the signal processing parameters represents.

Claims (13)

1. Programmable hearing aid (1, 1') with an amplifier and transmitter element (4, 4') the transmission properties of which can be adjusted between microphone (2) and earpiece (3) to different transmission characteristics, whereby a plurality of scan points (5) are present in the signal path between the microphone (2) and the earpiece (3) to scan signals (6, 6'), characterized in that one module (12) is present to select one or a plurality of scan signals at one or a plurality of scan points and one module (7) is present to transform the selected scan signal(s) from the time range to the frequency range and one module (9) is present in the frequency range to evaluate the signals (8) transferred to the frequency range, whereby the module (9) for evaluating the signals (8) transferred to the frequency range is set up to generate control signals (10) in the frequency range, which can be output to the amplifier and transmitter element (4) to select parameters of the amplifier and transmitter element stored in a data storage unit (11) assigned to the signal path or to change or to change the amplifier and transmitter element characteristics.
2. Hearing aid according to Claim 1,
   characterized in that in the case of an amplifier and transmitter element (4) for analog signal processing, a plurality of scan points (5) are present for analog signals (6), whereby the module (12) for selecting one or a plurality of scan signals selects one or a plurality of scan signals and then converts the selected scan signal(s) (13) by means of an analog/digital converter (14), whereby the resulting digital signal(s) (15) is/are fed to the module (7) for transforming the selected scan signal(s) from the time range to the frequency range.
3. Hearing aid according to Claim 1,
   characterized in that in the case of an amplifier and transmitter element (4') for digital signal processing a plurality of scan points (5) are present for digital signals (6'), whereby the module (12) for selecting one or a plurality of scan signals selects one or a plurality of scan signals and whereby the selected digital scan signal(s) (13') is/are fed directly to the module (7) for transforming the selected scan signal(s) from the time range to the frequency range.
4. Hearing aid according to one of Claims 1 to 3,
   characterized in that in the frequency range means (16) are present for identifying the system status of the hearing aid (1, 1'), the output signals (17) of which can be fed to the module (9) for evaluating the signals transferred to the frequency range, whereby said output signals (17) can be taken into account when generating the control signals (10).
5. Hearing aid according to one or a plurality of Claims 1 to 4,
   characterized in that control signals (18) from a control module (19) can be fed to the module (12) for selecting one or a plurality of scan signals (13, 13') and the selection of the scan signal(s) can be influenced by this.
6. Hearing aid according to Claim 1,
   characterized in that the transformation of the signals from the time range to the frequency range can be effected in a manner known per se according to the discrete Fourier transformation or the fast Fourier transformation or according to a discrete cosine transformation or a discrete wavelet transformation.
7. Hearing aid according to one or a plurality of Claims 1 to 6,
   characterized in that the module (9) for evaluating the signals (8) transferred to the frequency range exchanges data in the frequency range with a storage unit (20), whereby in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range outputs signals (21) to the storage unit (20) and prompts the storage unit to output specific data (22) to the amplifier and transmitter element (4) or takes data (23) from the storage unit (20), processes it and outputs it as control signals (10) to the amplifier and transmitter element (4).
8. Hearing aid according to one or a plurality of Claims 1 to 7,
   characterized in that in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range comprises a component (24) to standardize the amplitude values, a component (25) to create frequency-related characteristic variables, a component (26) to create temporal characteristic variables, a component (27) to calculate similarity criteria and a component (28) to determine the hearing program to be activated in each instance.
9. Hearing aid according to one or a plurality of Claims 1 to 7,
   characterized in that in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range comprises a component (24) to standardize the amplitude values, a component (25) to create frequency-related characteristic variables, a component (26) to create temporal characteristic variables, a component (29) to fuzzify, a component (30) to create inferences, a component (31) to defuzzify the similarity criteria and a component (28) to determine the hearing program to be activated in each instance.
10. Hearing aid according to one or a plurality of Claims 1 to 7,
    characterized in that in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range comprises a component (24) to standardize the amplitude values, a component (25) to create frequency-related characteristic variables, a component (26) to create temporal characteristic variables and a component (32) to provide a neuronal structure to determine the hearing program to be activated in each instance.
11. Hearing aid according to one or a plurality of Claims 1 to 7,
    characterized in that in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range comprises a component (24) to standardize the amplitude values and a component (33) to determine the individual signal processing parameters according to a predefined mathematical calculation.
12. Hearing aid according to one or a plurality of Claims 1 to 7,
    characterized in that in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range comprises a component (24) to standardize the amplitude values, a component (25) to create frequency-related characteristic variables, a component (26) to create temporal characteristic variables, a component (34) to fuzzify, a component (35) to create inferences and a component (36) to defuzzify the individual signal processing parameters to be output.
13. Hearing aid according to one or a plurality of Claims 1 to 7,
    characterized in that in the frequency range the module (9) for evaluating the signals (8) transferred to the frequency range comprises a component (24) to standardize the amplitude values, a component (25) to create frequency-related characteristic variables, a component (26) to create temporal characteristic variables and a component (37) to provide a neuronal structure to determine the individual signal processing parameters.

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