EP0674462B1 - Device for the fitting of programmable hearing aids - Google Patents

Description

The invention relates to a device for adapting programmable Hearing aids comprising a signal transmission data processing unit that can be coupled to the hearing aid, into the hearing loss of the hearing aid wearer to be treated characteristic data can be entered and wherein the data processing unit furthermore, characteristic data of the hearing aid can be supplied or from a data carrier of the data processing unit are available.

It is known hearing aids to the individual's hearing loss to adapt to the hearing aid wearer to be supplied. Furthermore, a Setting the hearing aid for different hearing situations intended. Programmable hearing aids offer a variety of adjustable parameters, which are the most optimal Adaptation of the electro-acoustic behavior of the hearing aid should enable the hearing loss to be compensated. At the same time, however, the adjustment is due to this multitude of parameters and the resulting diversity possible Setting combinations for the hearing care professional always more difficult. This can lead to incorrect fitting of the hearing aid lead to or the non-optimal use of all customization options.

A device for adaptation is known from EP 0 363 609 A1 programmable hearing aids known, comprising one over a Data transmission unit that can be coupled to the hearing aid, into the hearing loss of the hearing aid wearer to be treated characteristic data can be entered and where the data processing unit further characteristic data of the hearing aid can be supplied or from a data carrier of the data processing unit are available.

A fuzzy logic controller is known from EP 0 573 845 A1, from a fuzzy circuit (FUZ) a control detector (RDEC), a control evaluation circuit (RA), one Inference circuit (INF), a defuzzification circuit (DFUZ) and a sequential control system (CTRL), whereby usually the code numbers (NA) for linguistic values of the output variables together with selection signals (SM) for detection the input variables affected by the respective rule can be formed and in addition to the values (ME) of the membership functions for the linguistic values of the input variables can be fed to the control evaluation circuit and in this for each linguistic value of the output variable a weighting signal (G) can be generated.

From Engebretson, A.M., Miller, J.D., "A computer program for fitting a master hearing aid to the residual hearing characteristics of individual patients ", J. Acoust. Soc. Am., Vol. 72, No. August 2, 1982, is an adjustment facility programmable hearing aids known, comprising one over a Data transmission unit that can be coupled to the hearing aid, into the hearing loss of the hearing aid wearer to be treated characteristic data can be entered and where the data processing unit further characteristic data of the hearing aid can be supplied or from a data carrier of the data processing unit are available. As a result, hearing aid setting data provided.

The object of the invention is to provide a device for adaptation programmable hearing aids to create the most possible enables optimal adaptation of the hearing aid to the hearing loss, the adaptation itself is easy to carry out and taking into account the hearing aid-specific properties of rules that can be specified by the hearing aid manufacturer are optimally usable.

According to the invention, this object is achieved when the The type mentioned in the introduction is solved in that the data processing unit has a fuzzy logic module, its computing unit the data and key data that can be entered and / or called up including processing rules from at least a rule base processed according to the principle of fuzzy logic and provides hearing aid setting data as a result.

The hearing care professional is thereby advantageously given the opportunity for hearing aid fitting by him a programming unit implemented according to the principle of fuzzy logic is available after entering the audiometric Data and the type of hearing aid to be adapted optimal and sensible coordinated settings proposes all hearing aid parameters. These suggested settings can be taken over completely or if necessary, after further acoustic measurements.

The fuzzy logic module or the data processing unit is e.g. primarily supplied by the hearing aid manufacturer. The The rules of the module are from the user of the adapter can be supplemented to the extent that in a data carrier of the module further processing rules for determining the hearing aid parameters can be entered based on the experience of the Acoustician.

Advantageous embodiments of the invention are characterized by Claims 2 to 6 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 einer erfindungsgemäßen Einrichtung zur Anpassung programmierbarer Hörgeräte,

Figuren 2 bis 4 beispielhafte Darstellungen des Grundprinzips für die Anwendung von Fuzzy-Logik bei der Ermittlung von Anpaßparametern eines programmierbaren Hörgerätes.

Show it:

FIG. 1 shows a block diagram of a device according to the invention for adapting programmable hearing aids,

Figures 2 to 4 exemplary representations of the basic principle for the use of fuzzy logic in the determination of adaptation parameters of a programmable hearing aid.

The invention shown schematically in Figure 1 Device for the implementation of a fuzzy logic system to determine the adjustment parameters for a programmable Hearing aid 2 is in the form of an independent programming device or in combination with a personal computer or in Can be connected to another data processing system. The device comprises a data processing unit 3, with an interface 12 for signal transmission 1 with the hearing aid 2 can be coupled. Signal transmission 1 can via a line connection or wirelessly. The Data processing unit 3 or an external one to the hearing device 2 The programming device has a fuzzy logic module 5. This Module 5 in turn comprises a computing unit 6 or one Processor with components for executing the fuzzy logic operations: Fuzzyfication 13, inference formation 14 and defuzzification 15. Furthermore, the fuzzy logic module 5 contains at least a rule base 7. On a data carrier of this rule base 7 or this set of rules are processing rules for Determination of hearing aid setting data can be called up, whereby to determine the hearing aid setting data / hearing aid parameters which the respective hearing loss of the supplying hearing aid wearer characteristic data 4 and Characteristics 11 of the respective given by the hearing aid manufacturer hearing aid 2 to be programmed into the determination or Calculation of the hearing aid setting data are included. The Enter the hearing loss related to the hearing impaired Data 4 takes place via an interface 8 to the computing unit 6 the data processing unit 3 or the fuzzy logic module 5. At 9 is a disk for the hearing aid specific Identifies characteristic data 11, also of the data processing unit 3 or the fuzzy logic module 5 is assigned and its specific hearing aid specified by the hearing aid manufacturer Characteristic data 11 can be supplied to or from the computing unit 6 these are available.

In the illustrated embodiment is next to the rule base 7, in the processing rules of the hearing aid manufacturer stored and available, an additional rule base of the hearing aid acoustician provided, the data carrier 10 the Hearing aid acousticians the possibility of additional storage of processing rules out there that come from their own Derive empirical values. The fitting of the hearing aid performing acousticians can in the 10th determine readable processing rules themselves, again change or correct while the manufacturer predefined processing rules of the first rule base 7 should not be changeable.

Advantages of the invention:

• die werksseitigen Standardeinstellungen für programamierbare Hörgeräte bzw. die einzelnen Hörsituationen übernehmen oder
• jeden Parameter des Hörgeräts bzw. der Hörsituation einzeln einstellen/modifizieren.

So far, hearing care professionals have only been able to adapt a programmable hearing aid either

• accept the factory default settings for programmable hearing aids or the individual listening situations or
• Set / modify each parameter of the hearing aid or the hearing situation individually.

The disadvantage of this procedure is that in the first case the customization options of the programmable Hearing aid are not used at all or in the second case, despite great adaptation effort, possibly not optimal or even incorrect setting of the hearing aid parameters takes place.

• Es ist die optimale und sinnvoll aufeinander abgestimmte Einstellung aller Hörgeräteparameter entsprechend den individuellen audiometrischen Daten des Hörschadens nach allgemein gültigen, vom Hörgerätehersteller vorgegebenen und geprüften Regeln möglich.
• Die Einstellung aller Parameter eines programmierbaren Hörgerätes ist eine komplexe Optimierungsaufgabe, die nicht immer in geschlossener, analytischer Form gelöst werden kann. Vielmehr spielen einzelne, aus der Erfahrung gewonnene Regeln hierbei eine wichtige Rolle. Dabei können sich bei entsprechender Konstellation der Eingabedaten und/oder Regelsätze durchaus auch einander teilweise widersprechende Forderungen für die Einstellung einzelner Parameter ergeben. Die Verarbeitung solcher zum Teil widersprüchlicher Teilergebnisse im Sinne eines Gesamtoptimums ist eine inhärente Fähigkeit der Fuzzy-Logik.
• Die in der Anpaßpraxis ermittelten audiometrischen Daten sind im allgemeinen mit relativ großen Toleranzen behaftet. Ein Anpaßmechanismus, welcher nach dem Prinzip der Fuzzy-Logik arbeitet, ist aufgrund der Fuzzyfizierung der Eingabedaten aber inhärent sehr robust gegenüber solchen Toleranzen, d.h. die unpräzisen Eingabedaten führen nicht oder nur geringfügig zu einer Verschlechterung des berechneten Parametersatzes für die Programmierung des Hörgerätes.

The matching device according to the invention, which is based on the principle of fuzzy logic, is distinguished in particular by the following advantages:

• The optimal and sensibly coordinated setting of all hearing aid parameters is possible in accordance with the individual audiometric data of the hearing damage according to generally applicable rules specified and tested by the hearing aid manufacturer.
• The setting of all parameters of a programmable hearing aid is a complex optimization task that cannot always be solved in a closed, analytical form. Rather, individual rules gained from experience play an important role here. Given a corresponding constellation of the input data and / or rule sets, there may also be partially conflicting requirements for the setting of individual parameters. The processing of such partially contradictory partial results in the sense of an overall optimum is an inherent ability of fuzzy logic.
• The audiometric data determined in the fitting practice generally have relatively large tolerances. An adaptation mechanism, which works on the principle of fuzzy logic, is inherently very robust against such tolerances due to the fuzzy input data, i.e. the imprecise input data does not or only slightly deteriorate the calculated parameter set for programming the hearing aid.

The following is an exemplary explanation of the application of fuzzy logic when determining adaptation parameters of a programmable hearing aid based on FIGS. 2 to 4 described.

According to Figures 2 to 4, the structure of the Processing of sizes shown using fuzzy logic. The first step for the implementation of a fuzzy logic structure is the definition of the linguistic variable for their input and output variables. For each of these sizes their terms are plotted on a numerical scale. The is above the x-axis of the coordinate system variable size A in units over a numerical Value scale shown. The degree of membership is in the y-axis specified. The "sharp" value A = 2 on the numerical For example, the value scale activates the term "A" is very small "with a degree of 0.6 and the term" A medium "with a degree of 0.2.

µ(A ist sehr klein) = 0,6;

µ(A ist mittel) = 0.2;

µ(A ist groß) = 0,0;

µ(A ist sehr groß) = 0,0.

The sharp value A = 2 is described after this fuzzification as a fuzzy value (linguistic variable) A with the following set of statements:

µ (A is very small) = 0.6;

µ (A is medium) = 0.2;

µ (A is large) = 0.0;

µ (A is very large) = 0.0.

µ is the "degree of fulfillment" or "degree of truth" respective statement.

The further processing of the sizes inside the fuzzy logic system, especially their connection according to the rules of the set of rules (inference) now takes place in this fuzzy Presentation.

The result of the entire linking operation will be on Output of the fuzzy logic system back into sharp values converted (defuzzification).

Regel 1:

if A ist groß and B ist groß then X ist groß and Y ist groß.

Regel 2:

if A ist klein or B ist groß then X ist mittel.

Regel 3:

if A ist klein and B ist klein then Y ist klein.

Figure 3 shows an overview of the logical structure of a fuzzy logic system that implements the following example set of rules:

Rule 1:

if A is big and B is big then X is big and Y is big.

Rule 2:

if A is small or B is large then X is medium.

Rule 3:

if A is small and B is small then Y is small.

Figure 4 illustrates in graphic form the functioning of this fuzzy logic system: the two sharp input variables A and B are fuzzyfied in the manner described above. In this example, the two operators and and or are implemented in the most common way as minimum and maximum formation. Other types of realization generally known from the literature could in principle also be considered for this. The degree of fulfillment of the linking operations now activate the terms of the fuzzy output variables to the extent required. By superimposing the activated terms of each output variable and forming their centroid, the sharp output variables of the fuzzy logic system result. Known methods can be used to implement this last step (defuzzification).

• Hörschwelle bei verschiedenen Frequenzen
• Unbehaglichkeitsschwelle bei verschiedenen Frequenzen
• Ergebnisse von Sprachverständlichkeitstests mit/ohne Störgeräuschen
• Subjektiver Höreindruck des Schwerhörigen im Sinne von Besser/Schlechter-Entscheidungen bei zu vergleichenden Situationen.

Exemplary embodiment for a fuzzy logic system for determining adaptation parameters of a programmable multi-channel hearing device:
The following parameters can be used as input variables for the fuzzy logic system for determining adaptation parameters:

• Hearing threshold at different frequencies
• Discomfort threshold at different frequencies
• Results of speech intelligibility tests with / without noise
• Subjective hearing impression of the hearing impaired in the sense of better / worse decisions in situations to be compared.

• Trennfrequenzen zwischen den einzelnen Kanälen
• Verstärkung(en)
• AGC-Schwelle(n); Schwelle(n) der automatisch arbeitenden Verstärkungsregelschaltung(en)
• AGC-Kompressionsfaktor(en)
• Peak-Clipping-Schwelle(n) von Begrenzungseinrichtungen
• Filtercharakteristiken (Grenzfrequenz, Flankensteilheit)
• Maximale Verstärkung

The following variables, for example, can be considered as output variables of a fuzzy logic system for determining adaptation parameters:

• Crossover frequencies between the individual channels
• Gain (s)
• AGC threshold (s); Threshold (s) of the automatic gain control circuit (s)
• AGC compression factor (s)
• Peak clipping threshold (s) of limiting devices
• Filter characteristics (cut-off frequency, edge steepness)
• Maximum gain

The example set of rules described below works assume that the US discomfort threshold and the hearing threshold HS of the patient determined at different frequencies were. (Nomenclature: "US # 1350" stands for discomfort threshold at 1350 Hz)

1. if (US#1350 - US#350) ist klein then UTF ist ca. 700Hz

2. if (US#1350 - US#350) ist groß and (US#1350 - US#700) ist groß then UTF ist größer als 700Hz

3. if (US#1350 - US#350) ist groß and (US#1350 - US#700) ist klein then UTF ist kleiner als 700Hz

The rule set for determining the lower crossover frequency UTF could then, for example. ring:

1.if (US # 1350 - US # 350) is small then UTF is about 700Hz

2. if (US # 1350 - US # 350) is large and (US # 1350 - US # 700) is large then UTF is larger than 700Hz

3. if (US # 1350 - US # 350) is large and (US # 1350 - US # 700) is small then UTF is less than 700Hz

1. if (US#2650 - US#1350) ist klein then OTF ist ca. 2000Hz

2. if (US#2650 - US#1350) ist groß and (US#2650 - US#2000) ist groß then OTF ist größer als 2000Hz

3. if (US#2650 - US#1350) ist groß and (US#2650 - US#2000) ist klein then OTF ist kleiner als 2000Hz.

The rule set for determining the upper crossover frequency (OTF) could be specified in an analogous manner with:

1.if (US # 2650 - US # 1350) is small then OTF is about 2000Hz

2. if (US # 2650 - US # 1350) is large and (US # 2650 - US # 2000) is large then OTF is larger than 2000Hz

3. if (US # 2650 - US # 1350) is large and (US # 2650 - US # 2000) is small then OTF is less than 2000Hz.

1. if (US#350) ist niedrig then AGCU ist niedrig

2. if (US#350) ist groß then AGCU ist hoch

The rules for determining the AGC threshold in the lower AGCU channel could be defined as follows:

1. if (US # 350) is low then AGCU is low

2. if (US # 350) is large then AGCU is high

1. if (HS#350) ist niedrig then GU ist mittel

2. if (HS#350) ist hoch then GU ist groß

The rule set for determining the gain in the lower channel GU could be:

1. if (HS # 350) is low then GU is medium

2. if (HS # 350) is high then GU is large

1. if (US#350) or (US#1350) or (US#2650) ist niedrig then PCS ist niedrig

2. if (US#350) and (US#1350) and (US#2650) ist hoch then PCS ist hoch.

One possibility of the rule set for setting the peak clipping threshold PCS is:

1.if (US # 350) or (US # 1350) or (US # 2650) is low then PCS is low

2. if (US # 350) and (US # 1350) and (US # 2650) is high then PCS is high.

Claims (6)

1. Device for adapting programmable hearing aids, comprising a data processing unit (3) which can be connected to the hearing aid (2) via a signal transmission path (1), it being possible to enter data (4) characterising the hearing loss of the relevant hearing aid wearer into said data processing unit, whereby characteristics (11) of the hearing aid can additionally be sent to the data processing unit or retrieved from a data carrier of the data processing unit, characterised in that the data processing unit (3) has a fuzzy logic module (5) whose arithmetic unit (6) processes the data (4) and characteristics (11) which can be entered and/or retrieved, including processing rules from at least one rule storage unit (7) according to the principle of fuzzy logic and as a result provides setting data for the hearing aid.
2. Device according to Claim 1, characterised in that the fuzzy logic module (5) contains at least one data carrier (7), on which processing rules for calculating setting data for the hearing aid - from the data (4) characterising the respective hearing loss of the relevant hearing aid wearer and taking account of the respective hearing aid characteristics (11) - is stored in retrievable fashion.
3. Device according to Claim 2, characterised in that an EEPROM or a diskette is used as a data carrier (7).
4. Device according to Claim 1, characterised in that the data processing unit (3) has a data carrier (9) for the data (11) specific to the hearing aid.
5. Device according to Claim 1 and 2, characterised in that the fuzzy logic module (5) contains an additional data carrier (10), on which the user of the adaptation means can in a retrievable fashion store processing rules which can be entered for hearing aid programming to calculate the setting data of the hearing aid.
6. Device according to one of Claims 1 to 5, characterised in that the fuzzy logic module (5) contains a processor as an arithmetic unit (6), said processor having components for fuzzification, inference and defuzzification of the data values (11) which can be sent via an interface (8) and from the data carrier (9) using the processing rules stored on the data carrier (7) or data carriers (7, 10).

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