EP2699020B1 - Method and device for determining a gain factor of a hearing aid - Google Patents

Description

The invention relates to a method for determining an amplification factor of a hearing aid. The method comprises the following steps: determining a strength of an approximately undisturbed signal, determining a strength of a noise signal, determining a strength of a disturbed signal, and generating the amplification factor. The strength of the approximately undisturbed signal and / or the strength of the interfering signal and / or the strength of the disturbed signal may each be, for example, a moving average of an instantaneous power, a moving average of an effective value or a moving average of a time course of another amplitude value (for example a sound pressure, a voltage or a current signal). The moving average can be generated for example by means of a sampling of a voltage signal and a subsequent filtering by means of a low-pass filter. The voltage signal may be a voltage signal that is generated, for example, by means of a half-wave rectifier or by means of a bridge rectifier. The rectified voltage signal can also be fed (without sampling) directly to low-pass filtering.

Moreover, the invention relates to a corresponding device.

Hearing aids are portable hearing aids that are used to care for the hearing impaired. To meet the numerous individual needs, different types of hearing aids such as behind-the-ear hearing aids (BTE), hearing aid with external handset (RIC: receiver in the canal ) and in-the-ear hearing aids (IDO), for example Concha hearing aids or canal hearing aids (ITE, CIC). The hearing aids listed by way of example are on the outer ear or in the auditory canal carried. In addition, bone conduction hearing aids, implantable or vibrotactile hearing aids are also available on the market. The stimulation of the damaged hearing takes place either mechanically or electrically.

Hearing aids have in principle as essential components an input transducer, an amplifier and an output transducer. The input transducer is usually a sound receiver, z. As a microphone, and / or an electromagnetic receiver, for. B. an induction coil. The output transducer is usually used as an electroacoustic transducer, z. As miniature speaker, or as an electromechanical transducer, z. B. bone conduction, realized. The amplifier is usually integrated in a signal processing unit. This basic structure is in FIG. 1 shown using the example of a behind-the-ear hearing aid. In a hearing aid housing 1 for carrying behind the ear, one or more microphones 2 for receiving the sound from the environment are installed. A signal processing unit 3, which is also integrated in the hearing aid housing 1, processes the microphone signals and amplifies them. The output signal of the signal processing unit 3 is transmitted to a loudspeaker or earpiece 4, which outputs an acoustic signal. The sound is optionally transmitted via a sound tube, which is fixed with an earmold in the ear canal, to the eardrum of the device carrier. The power supply of the hearing device and in particular the signal processing unit 3 is effected by a likewise integrated into the hearing aid housing 1 battery. 5

Noise reduction algorithms used in today's hearing aids are mostly based on the following equation for a Wiener filter. In this case, an amplification factor Q1 is calculated as the quotient of a determined magnitude Xpi of an approximately undisturbed signal Xi divided by a sum of the determined magnitude Xpi of the approximately undisturbed signal X and a determined magnitude SSpi of an interference signal SSi: Q1 = Xpi / (Xpi + SSpi) ,

With a poor signal-to-noise ratio, the gain becomes very small and thus can become difficult to handle numerically (for example due to quantization errors). A poor signal-to-noise ratio is understood here and below to mean a small ratio Xpi / Ypi between the determined magnitude Xpi of the approximately undisturbed signal Xi and the determined magnitude Ypi of the disturbed signal Yi.

For this reason, when applying the above equation for a Wiener filter, it is common today to limit the gain Q1 down by limiting attenuation to 6 dB or 10 dB.

The invention has for its object to provide an alternative method by which a reliable determination of a gain factor can be performed even with poor signal-to-noise ratios.

According to the invention, this object is achieved in that the generation of the amplification factor comprises the following steps: determining a strength of an approximately undisturbed signal, determining a strength of a spurious signal, determining a strength of a disturbed signal and generating the amplification factor. Generating the gain factor comprises the steps of: forming a counter, the counter comprising a sum having a first sum component formed by multiplying the magnitude of the approximately undisturbed signal by a first weight, and a second sum component obtained by multiplying the magnitude forming the denominated signal with a second weight, forming a denominator comprising as a first summand the counter and as a second summand the strength of the interfering signal, and determining the amplification factor by forming a quotient of the numerator divided by the denominator.

With respect to the device, this object is achieved that the device is prepared for carrying out the method according to the invention.

Due to the special form of the denominator of the quotient, the range of values of the amplification factor (under boundary conditions, which are explained in the figure description) to a numerically good manageable range (for example, between 0.5 and 1) implicitly and in a continuously differentiable manner can be limited. By limiting in a "continuously differentiable manner" is meant that a non-continuously differentiable dependence of the gain on a magnitude of the distorted signal and / or on a strength of the interfering signal is avoided.

In that the method also comprises the step of determining a strength of a disturbed signal and in that the forming of the counter comprises adding up the first summation component and a second summation component which is formed by multiplying the strength of the disturbed signal by a second weighting Influence of the approximately undisturbed signal on a signal sink increases when a good signal-to-noise ratio is present, and the influence of the approximately undisturbed signal on the signal sink is reduced if there is a poor signal-to-noise ratio. The signal sink can be, for example, the ear of a hearing aid wearer, for whom an acoustic signal is generated in consideration of the disturbed signal.

It may also be advantageous if the second weighting is determined by subtracting the first weighting from a constant value. In this way, an attenuation of one of the two signals is adapted to an attenuation of the other signal by means of an operation which can be carried out quickly and efficiently with minimal effort.

A further embodiment provides that the first weighting by means of a handle by hand is adjustable. Alternatively or in addition the first weighting can be adjustable by means of an automatic control. The automatic control or regulation can set the first weighting, for example, as a function of an evaluation of the approximately undisturbed signal and / or the interference signal and / or the disturbed signal. Alternatively or additionally, it is also conceivable for the automatic control or regulation to set the first weighting as a function of an evaluation of the first signal defined below and / or of the second signal defined below and / or of the third signal defined below. Accordingly, the feature combinations described for adjustability of the first weighting can alternatively or additionally also be provided for adjustability of the second weighting.

An alternative or additional development provides that the approximately undisturbed signal is a band-limited part of a first signal and / or that the interference signal is a band-limited part of a second signal and / or that the disturbed signal is a band-limited part of a third signal. By means of a frequency-wise application of the method, specifically those signal components of the disturbed signal which have a poor signal-to-noise ratio can be attenuated, while those signal components of the disturbed signal which have a good signal-to-noise ratio are attenuated or are not attenuated.

For an acoustic application, it may be useful if the interfering signal is detected from a second signal received from a second spatial direction that deviates from a first spatial direction from which a first signal is received from which the approximate one undisturbed signal is derived. As a result, signals are preferably supplied to the signal sink which are received from the first spatial direction, with signals received from the second direction being suppressed.

Particularly preferred is when the second spatial direction is opposite to the first spatial direction. As a result, an optimal suppression of a noise signal is possible, which does not come from the Nutzquelle.

A preferred embodiment results when the perturbed signal is derived from a third signal received with a directional selectivity that is less than a directional selectivity with which the second signal is received.

An alternative or additional possible development is that the disturbed signal is derived from a third signal which is received with a directional selectivity which is less than a directional selectivity with which the first signal is received. Each of the two aforementioned measures contributes to the fact that the signal sink can also be supplied with undamped or attenuated signals which come from directions other than the first direction.

It is particularly preferred if the first, second and / or third signal is an acoustic signal which is detected by means of a hearing aid. As a result, the method can be used to improve a benefit of a hearing aid.

FIG 1

ein Hörhilfegerät gemäß dem Stand der Technik im stark vereinfachten Blockschaltbild,

FIG 2

ein schematisches Blockschaltbild einer Vorrichtung zum Bestimmen eines Verstärkungsfaktors eines Hörhilfegeräts,

FIG 3

ein dreidimensionales Diagramm über die Abhängigkeit des Verstärkungsfaktors von einer ersten Pegeldifferenz zwischen einem Pegel des näherungsweise ungestörten Signals und einem Pegel des gestörten Signals und einer zweiten Pegeldifferenz zwischen einem Pegel des Störsignals und einem Pegel des gestörten Signals für den Fall, dass das gestörte Signal nicht berücksichtigt wird,

FIG 4

ein dreidimensionales Diagramm über die Abhängigkeit des Verstärkungsfaktors von einer ersten Pegeldifferenz zwischen einem Pegel des näherungsweise ungestörten Signals und einem Pegel des gestörten Signals und einer zweiten Pegeldifferenz zwischen einem Pegel des Störsignals zu einem Pegel des gestörten Signals für den Fall, dass das näherungsweise ungestörte Signal nicht berücksichtigt wird,

FIG 5

ein dreidimensionales Diagramm über die Abhängigkeit des Verstärkungsfaktors von einer ersten Pegeldifferenz zwischen einem Pegel des näherungsweise ungestörten Signals und einem Pegel des gestörten Signals und einer zweiten Pegeldifferenz zwischen einem Pegel des Störsignals und einem Pegel des gestörten Signals für den Fall, dass das näherungsweise ungestörte und das gestörte Signal je zur Hälfte berücksichtigt werden, und

FIG 6

ein schematisches Ablaufdiagramm eines Verfahrens zum Bestimmen eines Verstärkungsfaktors eines Hörhilfegeräts.

The invention is explained in more detail with reference to the accompanying drawings, in which:

FIG. 1

a hearing aid according to the prior art in a highly simplified block diagram,

FIG. 2

1 is a schematic block diagram of a device for determining a gain factor of a hearing aid;

FIG. 3

a three-dimensional graph of the dependence of the gain of a first level difference between a level of approximately undisturbed signal and a level of the disturbed signal and a second level difference between a level of the interfering signal and a level of the disturbed signal in the event that does not take into account the disturbed signal becomes,

FIG. 4

a three-dimensional diagram of the dependence of the gain of a first level difference between a level of approximately undisturbed signal and a level of the disturbed signal and a second level difference between a level of the interfering signal to a level of the disturbed signal in the event that the approximately undisturbed signal is not is taken into account

FIG. 5

a three-dimensional diagram of the dependence of the gain of a first level difference between a level of the approximately undisturbed signal and a level of the disturbed signal and a second level difference between a level of the interfering signal and a level of the disturbed signal in the event that the approximately undisturbed and disturbed signal can be considered in half, and

FIG. 6

a schematic flow diagram of a method for determining a gain of a hearing aid.

The embodiments described in more detail below represent preferred embodiments of the present invention.

FIG. 1 shows in a simplified block diagram the structure of a hearing aid according to the prior art. Hearing aids have in principle as essential components one or more input transducers, an amplifier and an output transducer. The input transducer is usually a sound receiver, such as a microphone, or an electromagnetic receiver, such as an induction coil. The output transducer is usually as an electro-acoustic transducer, eg miniature speaker or handset, or as an electromechanical transducer, eg bone conduction, realized. The amplifier is usually integrated in a signal processing unit. This basic structure is in FIG. 1 illustrated by the example of a behind-the-ear hearing aid 1. In a hearing aid housing 2 for carrying behind the ear two microphones 3 and 4 are installed for receiving the sound from the environment. A signal processing unit 5, which is also integrated into the hearing aid housing 2, processes the microphone signals and amplifies them. The output signal of the signal processing unit 5 is transmitted to a loudspeaker or earpiece 6, which outputs an acoustic signal. If necessary, the sound is transmitted to the eardrum of the hearing aid wearer via a sound tube, which is fixed in the auditory canal with an earmold. The power supply of the hearing device and in particular of the signal processing unit 5 is effected by a likewise integrated into the hearing aid housing 2 battery. 7

In the FIG. 2 Device 10 for determining a gain factor of a hearing aid shown has three inputs EYi, ESSi, EXi for each microphone signal Y ', SS', X '. The first input EXi is provided for a bandpass-limited microphone signal Xi which is received from a direction RX in which there is an acoustic useful source QX whose sound signal X "is to be supplied to an ear 20 of a hearing aid wearer in a conditioned form. Si is provided for a bandpass-limited microphone signal SSi, which is received from a direction RSS, in which there is an acoustic interference source QSS, whose sound signal The third input EYi is for a bandpass-limited microphone signal Yi which is received with an omnidirectional characteristic, ie one or more sound sources QZ, QSS, which are in one or more arbitrary indeterminate directions which are not coincide with the direction RX.

For the sake of clarity are in the FIG. 2 different microphones MX, MY, MSS for generating the microphone signals Y ', Y' and SS 'drawn. Typically, however, all three microphone signals Y ', Y' and SS 'are generated by means of a single double microphone whose directional characteristic is electronically variable. The tips of the directional arrows RX, RY and RSS from the different sound sources QSS, QX, QZ thus typically end at the same location.

The double microphone preferably comprises a first and a second microphone, each having an omnidirectional receiving characteristic. Typically, the two microphones are arranged at a distance of 6 to 10 mm in the direction RX one behind the other. By means of a propagation delay of the electrical output signal of one of the two microphones, which is adapted to an acoustic transit time difference in the RX direction, and a subtraction of the delay-delayed output signal from the output signal of the other microphone (or by means of a reverse subtraction), the double microphone gets a kidney in its terminal behavior -Empfangscharakteristik.

The units FX, FY and FSS are filter banks which are prepared to convert the respective microphone signal X ', Y' or SS 'into a plurality of band-limited input signals Xi, Yi, SSi which are adjacent in the frequency domain. The letter i in the reference numbers indicates that the circuit parts between the filter banks FSS, FX, FY and the frequency multiplexer C are executed several times.

The signal strength detectors PXi, PYi and PSSi are prepared from the band-limited input signals Xi, Yi, SSi each to determine a signal strength Xpi, Ypi, SSpi.

Alternatively, at least one of the units FX, FY, FSS or each of the units FX, FY, FSS can be designed to convert the microphone signal X ', Y' or SS 'supplied thereto in the time domain by means of a Fourier transformer into an amplitude distribution density function over the frequency and to sample their signal strength in (preferably equidistant) frequency intervals.

The apparatus 10 comprises a differential adder DAi which adds up the two signal strengths Xpi and Ypi and provides the added signal strength value as a first intermediate signal Zi (counter Zi). Prior to adding the signal strengths of the two signal strengths Xpi, Ypi, the differential adder DAi applies a first weight WXi to the signal strength Xpi of the approximately undisturbed signal Xi and a second weight WYi to the signal strength Ypi of the disturbed signal Yi. The differential adder DAi has an input EWi for a weighting signal WXSi whose value WXi can be set manually and / or whose value WXi is set by means of an automatic control or regulation (not shown in the figures). The first weight WXi corresponds to the value of the weighting signal WXSi. The differential adder DAi determines the second weighting WYi = 1-WXi by subtracting the first weighting WXi from FIG.

The device 10 comprises a summer Si, which adds the first intermediate signal Zi (counter Zi) and the signal strength of the interference signal SSi. The result is a second intermediate signal ZS2i. A zero-avoidance unit NVEi converts the second intermediate signal ZS2i into a zero-set third intermediate signal Ni (denominator Ni). This avoids a subsequent division by zero. In addition, the device 10 comprises a quotient generator QBi, the one Amplification factor Qi (quotient Qi) by dividing the first intermediate signal Zi (counter Zi) by the third intermediate signal Ni (denominator Ni) generated. In addition, the device 10 comprises a multiplier Mi for applying the gain Qi to the approximately undisturbed signal Xi and forming a frequency band specific output Xai. Furthermore, the device 10 comprises a frequency multiplexer C for combining the frequency band-specific output signals Xai of the different frequency bands into a synthesized output signal Xa '. The synthesized output signal Xa 'is supplied to a sound generator SG, which converts the synthesized output signal Xa' into a corresponding sound signal Xa ", which is supplied to an ear 20 of a hearing aid wearer.

The 3, 4 . 5 show in dB (ie in logarithmic representation) for different values of the weighting signal WXi such as a gain Qi of a first level difference V1 between a signal strength Xpi of the approximately undisturbed signal Xi and a signal strength Ypi of the disturbed signal Yi and a second level difference V2 between a signal strength SSpi of the interfering signal SSi and the signal strength Ypi of the disturbed signal Yi.

In FIG. 3 For example, the first weight WXi is set so that the signal strength Ypi of the perturbed signal Yi does not enter into the gain Qi. In FIG. 4 the first weighting WXi is set such that approximately the signal strength Ypi of the undisturbed signal Xi is not included in the gain factor Qi. at FIG. 5 the first weighting WXi is set so that the signal strength Xpi, Ypi of the approximately undisturbed signal Xi and of the perturbed signal Yi are each half in the amplification factor Qi.

As the right upper edge 32 of the gain curve QiV of all three graphs shows, the gain Qi is high regardless of the weight WXi in any case when the second level difference V2 is low.

As the lower corner 34 of the gain curve QiV of all three graphs shows, the gain Qi is high regardless of the weight WXi in each case in which the first level difference V1 is low and at the same time the second level difference V2 is high.

The weight WXi thus has a significant effect on the gain Qi only if the second level difference V2 is not small. In this case, the larger the first level difference V1, the greater the effect on the gain Qi.

That in the FIG. 6 The method 100 for determining an amplification factor of a hearing aid shown comprises the following steps: In a first step 110, a signal strength Xpi of an approximately undisturbed signal Xi is determined. In a second step 120, a signal strength SSpi of an interference signal SSi is determined. In a third step 130, a signal strength Ypi of a disturbed signal Yi is determined. In a fourth step 140, a gain factor Qi is generated. The generation 140 of the amplification factor Qi comprises the following substeps. In a first sub-step 142, a counter Zi is formed. The counter Zi comprises a sum having a first sum component formed by multiplying the signal strength Xpi of the approximately undisturbed signal Xi by a first weight WXi, and a second sum component obtained by multiplying the signal strength Ypi of the distorted signal Yi by a second weight WYi is formed. In a second sub-step 144, a denominator Ni is formed which comprises the counter Zi as a first summand and the signal strength SSpi of the interference signal SSi as a second summand. In a third sub-step 146, a gain factor Qi is determined by forming a quotient Qi from the counter Zi divided by the denominator Ni.

It is particularly preferred if the second weighting WYi is determined by subtracting the first weighting WXi from a constant value.

It is also expedient if the first weighting WXi can be set manually by means of a handle and / or if the first weighting WXi can be set by means of an automatic control or and / or if the second weighting WYi can be set manually by means of a handle and / or when the second weighting WYi is adjustable by means of an automatic control.

In acoustic applications, it may be advantageous if the approximately undisturbed signal Xi is a band-limited part of a first microphone signal X 'and / or if the interference signal SSi is a band-limited part of a second microphone signal SS' and / or if the disturbed signal Yi is a band-limited part of a third microphone signal Y '.

For direction-specific suppression of interference signals, it is expedient if the interference signal SSi is determined from a second signal SS ', which is received from a second spatial direction RSS, which deviates from a first spatial direction RX, from which a first signal X' is received from which the approximately undisturbed signal Xi is derived.

Preferably, the first spatial direction RX is opposite to the second spatial direction RSS.

A further development provides that the disturbed signal Yi is derived from a third signal Y 'which is received with a directional selectivity which is less than a directional selectivity with which the second signal SS' is received.

An alternatively or additionally possible development provides that the disturbed signal Yi from a third signal Y ' is derived, which is received with a directional selectivity that is less than a directional selectivity with which the first signal X 'is received.

In hearing aid applications, the first X ', second SS', and / or third signal Y 'is typically an audible signal detected by a hearing aid 10.

According to the invention, it is therefore proposed to determine the amplification factor Qi according to the following formula (1): $$\mathrm{Qi}=\left(\mathrm{.xpi}\cdot \mathrm{WXi}+\mathrm{ypi}\cdot \mathrm{wyi}\right)/\left(\mathrm{.xpi}\cdot \mathrm{WXi}+\mathrm{ypi}\cdot \mathrm{wyi}+\mathrm{SSPI}\right)\mathrm{,}$$

For Xpi WXi + Ypi WYi> 0 this is equivalent to the $$\mathrm{Qi}=\mathrm{1}/\left(\mathrm{1}+\mathrm{SSPI}/\left(\mathrm{.xpi}\cdot \mathrm{WXi}+\mathrm{ypi}\cdot \mathrm{wyi}\right)\right)\mathrm{,}$$

Assuming that Ypi = SSpi + Xpi and WXi + WYi = 1, formula (3) results: $$\mathrm{Qi}=\mathrm{1}/\left(\mathrm{1}+\mathrm{SSPI}/\left(\mathrm{.xpi}+\mathrm{SSPI}\cdot \mathrm{wyi}\right)\right)\mathrm{,}$$

If a ratio (signal-to-noise ratio) of the magnitude Xpi of the undisturbed signal to the magnitude SSpi of the interference signal is defined as v: Xpi / SSpi, this results in formula (4): $$\mathrm{Qi}=\mathrm{1}/\left(\mathrm{1}+\mathrm{1}/\left(\mathrm{v}+\mathrm{wyi}\right)\right)\mathrm{,}$$

In a first extreme case, the interference signal has a negligible strength, so that v is a very high value and then the gain factor Qi (irrespective of the ratio between WXi and WYi) is calculated approximately as follows: $$\mathrm{Qi}=1.$$

In a second extreme case, the magnitude SSpi of the distorted signal is approximately equal to the magnitude Ypi of the interfering signal, so that the magnitude Xpi of the undisturbed signal is then negligible, v is approximately zero, and then the gain Qi is approximately calculated as follows: Qi = 1 / (1 + 1 / WYi). If the second weighting WYi is between 0 and 1, this results in a gain factor for the second extreme case, depending on the size of the second weighting WYi Qi, which is between 0 and 0.5.

In an intermediate case, the magnitude SSpi of the interfering signal differs only insignificantly from the magnitude Xpi of the undisturbed signal, so that v = 1 and the gain Qi is calculated approximately as follows: Qi = 1 / (1 + 1 / (1 + wyi)). Thus, when the second weighting WYi is between 0 and 1, depending on the magnitude of the second weighting WYi, there is a gain Qi for the intermediate case which is between 1/2 and 2/3.

Typically, WYi is set to a value greater than 0.1, preferably greater than 0.2, more preferably greater than 0.4. Alternatively or additionally, WYi is set to a value which is less than 0.9, preferably greater than 0.8, more preferably less than 0.6.

In a typical case, approximately v = 0.8, and the gain Qi is then approximately calculated as follows: Qi = 1 / (1 + 1 / (0.8 + WYi)). This results in an attenuation of 6 dB = 0.5 when WYi = 0.2. At WYi = 0.8, the attenuation is then about 0.6. If WYi is less than 0.2, attenuation values smaller than 0.5 result in this case.

With formula (4) it is possible to calculate how big (v + WYi) must be, so that the amplification factor Qi does not fall below a certain minimum value Qmin (Qi> = Qmin). From Qmin <= 1 / (1 + 1 / (v + WYi)), for positive values of (v + WYi), formula (5) follows: v + WYi> = Qmin / (1-Qmin).

If the amplification factor Qi should be at least 0.5 (ie the damping factor at most 6dB), then v + WYi must be at least 1 (WYi> = 1-v). For this must then apply: $$\mathrm{wyi}>=1-\mathrm{.xpi}/\mathrm{SSPI}\mathrm{,}$$

With WYi = 1 - WXi then WXi <= v, ie: $$\mathrm{WXi}<=\mathrm{.xpi}/\mathrm{SSPI}\mathrm{,}$$

It may therefore be expedient to further develop the embodiments of the description defined in the claims and / or the description by limiting or adjusting the first weighting WXi by means of an automatic control or regulation to the value v = Xpi / SSpi and / or the second weight WYi is limited or set to the value (1 - Xpi / SSpi) = (1-v) by means of an automatic control or down control.

Claims (10)

1. Method (100) for determining a gain factor (Qi) of a hearing aid, wherein the method (100) comprises the following steps:

   - establishing (110) a strength (Xpi) of an approximately undisturbed signal (Xi),

   - establishing (120) a strength (SSpi) of an interference signal (SSi),

   - establishing (130) a strength (Ypi) of a disturbed signal (Yi),

   - generating (140) the gain factor (Qi),

   characterized in that
   generating (140) the gain factor (Qi) comprises the following steps:

   - forming (142) a numerator (Zi), wherein the numerator (Zi) comprises a sum with a first sum component, which is formed by multiplying the strength (Xpi) of the approximately undisturbed signal (Xi) by a first weight (WXi), and comprises a second sum component, which is formed by multiplying the strength (Ypi) of the disturbed signal (Yi) by a second weight (WYi);

   - forming (144) a denominator (Ni), which comprises as a first summand the numerator (Zi) and as a second summand the strength (SSpi) of the interference signal (SSi);

   - establishing (146) the gain factor (Qi) by forming a quotient (Qi) of the numerator (Zi) divided by the denominator (Ni).
2. Method (100) according to Claim 1, characterized in that the second weight (WYi) is established by subtracting the first weight (WXi) from a constant value.
3. Method (100) according to Claim 1 or 2, characterized in that the first weight (WXi) is manually adjustable by means of a handle and/or in that the first weight (WXi) is adjustable by means of an automated open-loop or closed-loop control and/or in that the second weight (WYi) is manually adjustable by means of a handle and/or in that the second weight (WYi) is adjustable by means of an automated open-loop or closed-loop control.
4. Method (100) according to one of Claims 1 to 3, characterized in that the approximately undisturbed signal (Xi) is a bandwidth-limited part of a first signal (X') and/or in that the interference signal (SSi) is a bandwidth-limited part of a second signal (SS') and/or in that the disturbed signal (Yi) is a bandwidth-limited part of a third signal (Y').
5. Method according to one of Claims 1 to 4, characterized in that the interference signal (SSi) is established from a second signal (SS') which is received from a second spatial direction (RSS) which deviates from a first spatial direction (RX) from which a first signal (X'), from which the approximately undisturbed signal (Xi) is derived, is received.
6. Method according to Claim 5, characterized in that the second spatial direction (RSS) is directed in the opposite direction to the first spatial direction (RX).
7. Method according to one of Claims 1 to 6, characterized in that the disturbed signal (Yi) is derived from a third signal (Y') which is received with a directional selectivity that is less than a directional selectivity with which the second signal (SS') is received.
8. Method according to one of Claims 1 to 7, characterized in that the disturbed signal (Yi) is derived from a third signal (Y') which is received with a directional selectivity that is less than a directional selectivity with which the first signal (X') is received.
9. Method according to one of Claims 5 to 8, characterized in that the first (X'), second (SS') and/or third signal (Y') is an acoustic signal which is detected by means of a hearing aid (10).
10. Device,
    characterized in that
    the device (10) is prepared to carry out a method (100) according to one of Claims 1 to 9.

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