EP3413588B1 - Method for characterizing a speaker in a hearing device, hearing device and test device for a hearing device - Google Patents

Description

The invention relates to a method for characterizing a listener in a hearing aid, the listener being embedded in an environment and having a response behavior which is influenced by the environment. The invention also relates to a hearing aid and a test device for a hearing aid.

A hearing aid is used to supply a user who is usually hearing impaired. For this purpose, the hearing aid has a microphone for recording sound signals in the environment and for converting these sound signals into electrical audio signals. These electrical audio signals are processed, usually amplified, by means of a control unit and passed on to a receiver, which converts the processed electrical audio signals back into sound signals and outputs them to the user. The listener uses a magnetic field to convert electricity into motion. The listener is therefore also referred to as an electro-acoustic converter. Depending on the type of hearing aid, the receiver sits in or on the user's ear. In the case of a BTE device that is worn behind the ear, the receiver sits in a housing of the hearing aid and the sound signals are conducted from the receiver into the ear via a sound tube. In the case of a RIC device, on the other hand, the receiver is inserted into the ear, for example by means of an otoplastic, whereas the rest of the hearing device is mainly worn outside the ear. An ITE device is fully inserted into the ear. Examples of ITE devices are ITC and CIC devices, which are worn in the ear canal or completely in the ear canal.

In the US 2003/0163021 A1 describes an implanted hearing aid with an electro-mechanical actuator which is coupled to the auditory bones. A magnetic field of the actuator is measured by means of an external test device and the coupling of the actuator to the auditory bones is then checked on the basis of the magnetic field

In the JP 2016-100793 describes a test device by means of which it is checked whether a hearing device is switched on.

In the WO 97/19573 is called a magnetic hearing aid system with which no acoustic signal is generated. In order to use such hearing aid systems with conventional test systems, a magneto-acoustic converter is described which represents a magnetic field of the hearing aid system as an acoustic signal.

As part of the processing of the electrical audio signals, the hearing aid is intended to achieve a specific output characteristic, or simply output, which is matched to the hearing ability of the user. The output characteristic specifies in particular how precisely an incoming sound signal is modified in order to obtain an outgoing sound signal with a certain output power, or power characteristic for short, which is then output to the user. For example, only certain frequency ranges should be amplified, but not other frequency ranges. For this purpose, an audiogram is usually created, with the knowledge of which the hearing aid is then suitably adjusted in a fitting session in order to achieve the desired output and to ensure optimal care. The control unit must therefore be configured in such a way that it modifies the electrical audio signals precisely in such a way that the desired output is achieved. The problem here is that the listener, as an additional link between the control unit and the user's ear, brings about a further change which must be taken into account accordingly. Along the signal path from the environment, to the microphone, to the control unit, to the listener and finally to the user's ear, the listener represents an additional transfer function. This transfer function defines the response behavior of the listener, i.e. how the listener converts a given audio signal into a sound signal. Further changes and transfer functions along the signal path result in particular from the individual dimensioning of the sound tube, the degree of soiling of an earpiece, e.g. an otoplastic, or the specific design of the earpiece, or a combination thereof.

The response behavior is initially logically dependent on the audio signal. Usually, for example, an increase in the amplitude of the audio signal also leads to a louder sound signal. This dependency on the audio signal is primarily used in hearing aids in order to achieve a specific output by shaping the audio signal by means of the control unit.

The response behavior of the listener is typically also dependent on the specific installation and / or usage situation of the listener, so that an individual Characterization of the response behavior is desirable. Accordingly, the invention is based on the object of specifying a method for characterizing a listener in a hearing aid as individually as possible. The method should be as simple as possible and as accurate as possible. Furthermore, it is an object to specify a hearing aid and a test device which are suitable for carrying out the method.

The object is achieved according to the invention by a method with the features according to claim 1, by a hearing aid with the features according to claim 11 and by a test device with the features according to claim 12. Advantageous configurations, developments and variants are the subject of the dependent claims. The statements in connection with the method also apply accordingly to the hearing aid and the test device and vice versa.

The method is used to characterize a listener in a hearing aid. In other words: the method is used to characterize a listener that is built into a hearing aid. The listener is thus a component of the hearing aid. The characterization also takes place in particular when the handset is installed. The listener is therefore preferably not removed for characterization. The receiver is used to convert electrical audio signals into sound signals and to output these sound signals to a user of the hearing aid. The electrical audio signals are also referred to as audio signals for short.

The hearing aid is preferably a hearing aid which is used to supply a user who is particularly hearing-impaired with amplified sound signals. Such a hearing aid is also referred to as a hearing aid. For this purpose, the hearing aid has a microphone for receiving a sound signal from the environment and for converting this sound signal into an electrical audio signal. Alternatively, preferably in addition, the hearing aid has a data connection via which an electrical audio signal is transmitted from an external source to the hearing aid. The external source is, for example, a telephone, a television, a music system or the like. The data connection is e.g. a Bluetooth receiver, to receive signals from a Bluetooth transmitter of the external source. The electrical audio signal is processed by means of a control unit, usually amplified, but at least modified, and passed on to the listener, who converts the processed audio signal back into a sound signal and outputs this to the user.

In principle, however, the invention is not restricted to such hearing aid devices. Rather, one variant of the method advantageously serves to characterize a listener in a hearing aid which is generally designed to output sound signals, that is, does not necessarily have a microphone and also does not necessarily serve to supply a hearing impaired user. In this context, the listener is also referred to as a loudspeaker. The hearing aid is then generally a hearing system which at least serves to output sound and in which the response behavior of the listener is potentially at risk of being influenced by its environment. For example, the hearing device is a headphone or a smartphone or generally a communication device, in particular a mobile communication device or a so-called "hearable". With such hearing aids, for example, there is also the risk that the receiver will become blocked and the response behavior will change as a result. Such a hearing aid also expediently has a control unit as described above and below.

The listener shows a certain response behavior. The response behavior is defined in particular by the ratio of the audio signal, that is to say an input signal from the listener, to the sound signal, that is to say an output signal from the listener. More precisely, the response behavior is defined by the ratio of the powers of the input signal and the output signal. The response behavior indicates the output power of the listener for a given input power. The response behavior is particularly frequency-dependent, ie audio signals of the same strength but different frequencies are converted into sound signals of different strengths under certain circumstances.

As part of the process, the listener converts an electrical audio signal, simply referred to as an audio signal or an electrical signal, into a sound signal, i.e. an acoustic signal. A magnetic field is generated in the process. This results in particular from the general mode of operation of the receiver, according to which the electrical signal is used as a drive for a movable component, which then generates pressure fluctuations. The listener is therefore a listener who uses a magnetic field to convert electricity into motion. Since the electrical signal represents an alternating electrical field, i.e. a current that varies over time, a magnetic field is also generated here. The strength of this magnetic field depends on the strength of the change in the current, which in turn depends on the load on the listener.

The generated magnetic field is measured by means of a magnetic field sensor. The magnetic field sensor then outputs a measurement signal. The measurement signal is, for example, a voltage that is proportional to the magnetic field, more precisely to the strength of the magnetic field. Alternatively, the measurement signal is a digital measurement signal. In one variant, the measurement signal is not proportional to the magnetic field and, in particular, is a preprocessed measurement signal. In principle, any sensor that is designed to measure a magnetic field and output a corresponding measurement signal is suitable as a magnetic field sensor, for example a Hall sensor or a simple conductor loop.

The listener is now characterized in that the response behavior of the listener is determined on the basis of the measured magnetic field. In other words: the response behavior of the listener is determined on the basis of the magnetic field, more precisely on the basis of the measurement signal of the magnetic field sensor. Overall, the listener is thus characterized by measuring a magnetic field that is generated when the receiver is in operation.

Since the listener's response behavior depends on its specific installation and / or usage situation, the characterization of the listener is not an isolated characterization of the listener as a single component, but rather a comprehensive characterization of the listener in its specific installation and / or usage situation. In this specific installation and / or use situation, the response behavior of the listener is influenced by his, in particular, immediate surroundings. In other words: the receiver is embedded in an environment in which a number of elements are arranged, which in particular are mechanically connected or coupled to the receiver and thereby influence the operation of the receiver. This also influences the listener's response behavior accordingly. The listener's environment is also referred to as the listener's environment.

The elements of the environment are regularly other components of the hearing aid, such as, for example, a sound tube, an otoplastic, a dome or also a housing of the hearing aid. The receiver is in particular part of a component complex in which the receiver is connected to a number of further components of the hearing aid. However, the elements of the environment do not necessarily have to be parts of the hearing aid, but are alternatively or additionally, for example, the ear canal of the user or cerumen that has accumulated in the vicinity of the listener. Such elements also influence the listener's response behavior. What all elements have in common is that they are coupled to the listener in such a way that those elements influence the listener's response behavior. A listener influenced in this way, who is embedded in a corresponding environment, is also referred to as a listener with coupling. The coupling largely determines the change in response behavior.

The characterization of the listener is therefore in particular a characterization of the listener and its coupling, ie the listener who is embedded in a specific environment that influences the listener's response behavior. Accordingly, more precisely, the method serves to characterize the response behavior of a listener who is embedded in an environment which contains a number of elements which influence the response behavior of the listener. As already mentioned, this does not necessarily result in an isolated characterization of the listener alone, but rather a characterization of the listener in particular as part of the hearing aid, ie in a specific installation situation, or in a specific usage situation, or both. As a result, the method serves i.e. for the individual characterization of the listener and for the individual determination of the response behavior of a listener in a specific installation and / or usage situation.

From what has been said above, it is clear that the response behavior may not be directly derived from the measurement signal itself. The response behavior is therefore expediently determined by inferring the response behavior from the measurement signal using a suitable model of, in particular, an acoustic coupling of the surroundings to the listener. The model is in particular an electro-magneto-mechano-acoustic model. The model expediently takes into account a principally known environment, i.e. what type of hearing aid it is and how generally the hearing aid and especially the listener are worn. Using the model, a control unit then selects suitable algorithms in order to infer the response behavior based on the measurement signal.

The invention is initially based in particular on the observation that, in addition to being dependent on the input signal, the response behavior of a listener is generally also dependent on the specific environment in which the listener is located. In the case of a hearing aid in particular, the response behavior is initially usually dependent on the installation situation, ie how and where the receiver is mounted in the hearing aid and with which other components the receiver is connected. In particular in the case of a sound tube which is connected to the receiver for sound transmission into the ear, the type and length of the often individually adapted sound tube determine the response behavior. Furthermore, the response behavior is typically also dependent on the specific use of the hearing aid by a user, in particular on the individual wearing style and the likewise individual degree of coupling between the listener and the user's ear, ie on the specific usage situation. In addition, the response behavior is also time-dependent insofar as the environment and the installation and / or usage situation can change over time, for example due to a progressive clogging of the earpiece with cerumen or due to an exchange of the sound tube. Overall, the response behavior is therefore dependent of a large number of, in particular, individual factors which may be unknown in the manufacture of the receiver and / or in the design and manufacture of the entire hearing aid or which change over time, or even both.

An essential advantage of the invention is that, by measuring the magnetic field, corresponding changes in the response behavior can be recognized particularly precisely in a simple manner. In particular, such individual or time-dependent changes are advantageously recognized which are not or cannot be taken into account during the manufacture of the hearing aid or in the context of a fitting session. Such a change is, for example, a progressive clogging with cerumen or an exchange or modification of a sound tube or an otoplastic or a dome of the hearing aid. An essential aspect here is in particular that the listener's response behavior is not, or at least not exclusively, isolated and determined in an ideal state. Rather, the response behavior is advantageously determined in a specific installation or use situation or both. As a result, changes that arise due to this installation and / or usage situation compared to a reference situation, e.g. an ideal state, are also recorded and preferably also monitored, in particular monitored on a recurring basis.

The method is based in particular on the knowledge that the magnetic field generated by the listener also reflects the listener's response behavior, since the response behavior is largely defined by the output power and this power and the magnetic field are each directly dependent on the current that is supplied to the listener. The magnetic field can thus be used profitably to determine precisely that response behavior and is also used accordingly within the scope of the present invention.

In principle, the response behavior can be determined and the listener can be characterized in that, for example, a test signal with a known strength is used as the audio signal and the strength of the signal generated therefrom Sound signal is measured. This is done, for example, by means of an impedance measurement, which ultimately measures the current through the earpiece and is therefore a measure of the output power, that is to say of the strength of the sound signal. The relationship is given here by a specific model, the knowledge of which enables a conclusion on the basis of the impedance measurement. The frequency-dependent response behavior is then carried out accordingly with several test signals of different frequencies. Other measurement methods and test procedures are also possible. As an alternative to such an impedance measurement, a so-called vibration measurement is also possible. A magnetic field measurement now has the particular advantage that it is significantly more accurate compared to an impedance or vibration measurement. The magnetic field itself is disturbed to a particularly small extent by the environment, whereas an impedance or vibration measurement due to additional electrical or mechanical connections to other parts or components may be very flawed. In the case of a magnetic field measurement, a measurement signal with a particularly large amplitude is also generated, which means that even the smallest changes are reliably detected and the response behavior can accordingly be determined with a particularly high degree of accuracy.

In a preferred embodiment, the environment is determined by an installation situation of the earphone and the environment has an element which is a component of the hearing aid. The component is connected to the receiver and, in particular, mechanically coupled to the receiver and influences its response behavior. By determining the response behavior, the influence of the installation situation on the response behavior is then automatically taken into account. Here, the element, more precisely the component, is preferably selected from a set of elements, including but not limited to: a sound tube, an otoplastic, a dome, a housing of the hearing aid.

Alternatively or additionally, the environment is preferably determined by a usage situation of the listener. By determining the response behavior, the influence of the usage situation on the response behavior is then advantageous automatically taken into account. The usage situation is selected from a set of situations, including but not limited to: a way of wearing the hearing aid, a degree of coupling between the receiver and an ear of the user, a degree of clogging, in particular of the receiver, by cerumen. Similar to the installation situation described above, the surroundings also contain a number of elements in the usage situation, which in particular are mechanically coupled to the receiver and thereby influence the response behavior. However, these elements are precisely no components of the hearing aid, but rather external elements, in particular the user's auditory canal, his ear or cerumen.

The knowledge of the response behavior advantageously enables a reaction to a change in the same. For this purpose, the response behavior is expediently determined and compared as an actual response behavior with a target response behavior. A difference is then determined between the actual response behavior and the target response behavior and the hearing aid is adjusted as a function of the difference. “Set” is understood in particular to mean that the hearing aid is controlled in such a way that the response behavior of the listener is changed in order to reduce the difference and preferably to eliminate it completely. The response behavior is preferably adapted to the target response behavior, particularly preferably in such a way that the response behavior corresponds to the target response behavior.

In an expedient embodiment, the hearing aid is adjusted by modifying the audio signal by means of the control unit in such a way that the difference is at least partially, preferably completely, compensated. In this way, in particular, an adjustment of the response behavior to the target response behavior is achieved.

As an alternative or in addition, the knowledge of the response behavior is used to output a warning signal. For this purpose, the response behavior is also expediently determined and compared as an actual response behavior with a target response behavior. Between the actual response behavior and the target response behavior a difference is determined and a warning signal is output as a function of the difference. In other words: if there is a difference or if there is a difference which is greater than a predefined threshold value, a warning signal is output. The warning signal is output, for example, acoustically via the receiver, optically, by means of an LED or transmitted to a remote control or base station for the hearing aid, in particular for output or storage there.

The embodiment with the warning signal is particularly expedient in order to indicate the same blockage in the case of a certain degree of blockage of the earpiece with cerumen and thereby advantageously to induce the user to clean it. The configuration with warning notice is used alternatively or additionally to recognize whether a certain sound tube has been mounted on the hearing aid and, if another sound tube has been mounted, to indicate that the wrong sound tube has been mounted or that an adjustment of the response behavior is necessary.

Alternatively or additionally, it is detected whether the receiver has a defect. A defect is, in particular, a distortion in the output of a sound signal due to a mechanical defect such as an impact or a fall. Such distortion is also known as total harmonic distortion, or THD for short. Alternatively, the defect is a failure or breakage of an electrical line. Alternatively, the defect is a wedging of several, in particular internal, components, i.e. components of the receiver.

The target response behavior is expediently determined by means of a calibration measurement. The calibration measurement is preferably carried out in a state in which there is an ideal response behavior, for example as part of a first initialization during production, in particular since the acoustic coupling of the listener is known at this point in time and a number of model parameters of the listener are extracted and preferably also stored . The model parameters indicate the coupling in particular. Alternatively or additionally, the calibration measurement is carried out as part of a fitting session or directly after or after cleaning the hearing aid or immediately after a new sound tube or a new earmold has been fitted. Alternatively or additionally, the calibration measurement takes place at or at the end of the production of the hearing aid and before it is delivered to the user. This is based in particular on the consideration of using a delivery state of the hearing aid as a basis for comparison for later changes in the response behavior. This is advantageous, for example, in order to detect damage or a malfunction of the handset.

In an advantageous development, several target response behaviors are determined, for example for different environments in which the hearing aid is worn, for different users of the hearing aid, for different operating modes of the hearing aid, for different sound tubes or for different otoplastics or for a combination thereof. Depending on the specific situation, a suitable target response behavior is then selected, with which the measured response behavior is compared.

In a suitable embodiment, the nominal response behavior is determined in the calibration measurement in the same way as the response behavior in general, i.e. in the present case by measuring the magnetic field. An initial magnetic field measurement is therefore carried out.

An embodiment is particularly preferred in which the response behavior, i.e. the transfer function of the listener, is parameterized by means of an adaptive filter by measuring the magnetic field and, depending on this, generating a measurement signal which is fed to the filter as a filter input signal. The measurement signal is generated by the magnetic field sensor and is, for example, a voltage. In a suitable embodiment, the filter is a Wiener filter. The filter has a filter function which is parameterized by a number of filter parameters. The measurement signal is now fed to the filter as a filter input signal, whereupon the filter automatically adapts the filter function to the filter input signal in order to map it. The filter parameters are changed accordingly.

In particular, the filter works independently and does not require a separate external setting, so it automatically adjusts and changes the filter parameters. The filter parameters therefore change with a change in the magnetic field, i.e. also with a change in the response behavior, so that the response behavior is advantageously parameterized by means of the filter parameters and is thereby also determined. Instead of measuring the response behavior in detail, only the filter parameters are used to determine the response behavior. The use of an adaptive filter has the particular advantage that such a filter adapts particularly quickly to changes and therefore changes in the response behavior are recognized and determined particularly quickly. Adapting the response behavior is not necessarily a task of the filter, i.e. the filter does not necessarily set the response behavior, but rather the filter primarily and in particular exclusively serves to parameterize the response behavior by the filter following it.

The magnetic field, or more precisely its strength, falls as the distance from the hearing aid increases. Therefore, the magnetic field is expediently measured as close as possible to or in the hearing aid, i.e. the magnetic field sensor is arranged as close as possible to or in the hearing aid. In the specific case of a hearing aid, the magnetic field can be measured particularly well around the hearing aid within a distance which is in the order of magnitude of one dimension of the hearing aid. Conventional hearing aids have dimensions of approximately 0.5 to 5 cm, and accordingly the magnetic field can be measured particularly effectively at a distance of up to a few centimeters and is therefore preferably also measured in this area.

In a preferred embodiment, the magnetic field sensor is arranged directly on the receiver, i.e. in particular at a distance of at most 3 cm, preferably at most 5 mm from the receiver, particularly preferably directly on or even in the receiver. The magnetic field is therefore measured directly on the listener and therefore where the magnetic field is particularly strong, so that the measurement is correspondingly accurate.

In a suitable variant, the hearing aid has a power supply, in particular a battery, which is connected to the by means of a power supply line Handset is connected to supply power to the handset, and the magnetic field sensor is arranged directly on the power supply line, ie in particular at a distance of at most 3cm, preferably at most 5mm from the power supply line, particularly preferably directly on or even in the power supply line. The aforementioned values are particularly suitable for a hearing aid which is designed as a hearing aid for a hearing-impaired user. In the case of other hearing aids, larger values are also suitable, in particular when the energy supply is stronger, ie provides more power, than in a hearing aid. The magnetic field is thus measured directly on the power supply line. This refinement is based in particular on the knowledge that the listener generates a changing load during operation and thus draws a current that varies over time from the power supply, which in turn generates a magnetic field. The handset therefore generates a magnetic field not only in its immediate vicinity, but also along the power supply line, which extends from the power supply to the handset, and at the same power supply. The magnetic field is therefore advantageously measured on the power supply line or on the power supply itself. A magnetic field measurement in the vicinity of the power supply line or the power supply is advantageous in that these are usually arranged outside the user's ear. Particularly in the case of a hearing aid in which the receiver is worn in the ear, the installation space around the receiver is naturally severely restricted, so that an additional magnetic field sensor on the receiver may not be possible under certain circumstances. Particularly in such cases, the magnetic field is then measured at another point and outside the ear, preferably, as described, in the vicinity of the power supply line or the power supply. Due to further components of the hearing aid which are connected to the power supply, a measurement on the power supply itself may be too imprecise, which is why a magnetic field measurement on the power supply line is preferred. The energy supply line is used in particular to supply the earpiece alone, that is to say no further components or consumers are connected to the energy supply by means of the energy supply line. This ensures that the measured Magnetic field is mainly and in particular caused solely by the operation of the handset.

In principle, however, a measurement of the magnetic field at other points is also possible and also suitable. The two variants mentioned above, however, represent particularly suitable positions and are accordingly preferred.

In a first preferred embodiment, the magnetic field sensor is integrated into the hearing aid, that is to say a component of the hearing aid. Overall, the hearing aid then has a receiver for converting an electrical audio signal into a sound signal while generating a magnetic field, and a magnetic field sensor, and additionally a control unit which is designed such that the magnetic field is measured by means of the magnetic field sensor, the receiver is characterized, by determining the listener's response behavior on the basis of the measured magnetic field. In this refinement, the hearing aid in particular automatically determines the response behavior of the listener, preferably continuously, alternatively, for example, only in a test mode. The hearing aid also expediently adjusts itself automatically as a function of the response behavior, in particular in order to set a specific target response behavior, as already described above. The user is advantageously informed about the measurement or about how the hearing aid is adjusting, or both. The user is informed, for example, by means of a warning signal as already described above.

In particular in the case of a magnetic field sensor which is integrated in the hearing aid, the method is preferably carried out in a normal operating mode of the hearing aid, ie in particular not during a fitting session or during the manufacture of the hearing aid. Rather, the characterization takes place in normal operation while the hearing aid is being worn or used by the user. In the normal operating mode, an electrical audio signal is modified by means of a control unit and then output as a sound signal by means of the earpiece. The electrical audio signal itself is generated in particular by means of a microphone which converts a sound signal from the environment into the audio signal. Alternatively, the audio signal is supplied from an external source. An external source is, for example, a streaming signal from, for example, a wireless system, ie a wireless system.

In a particularly suitable embodiment, the hearing aid has a telephone coil and this is the magnetic field sensor, ie the telephone coil is used as a magnetic field sensor. In other words: the hearing aid has a telephone coil which is placed or arranged in such a way that it can and is also used as a magnetic field sensor. In particular, precise positioning of the telephone coil is important in order to measure the magnetic field as effectively as possible. The telecoil is also known as a telecoil or T-coil. This is based on the consideration that the telephone coil is naturally already designed for measuring magnetic fields and can therefore also be used profitably for the measurement of the magnetic field, which is generated by the listener, as described here. This significantly reduces the design effort, because a telephone coil is already installed as standard in many hearing aids. A magnetic field sensor as an additional component is advantageously dispensed with, rather the existing hardware is used, namely the telephone coil. The telephone coil is a coil, for example a conductor loop, which receives signals by induction. A transmitter, for example a telephone with an electrodynamically operating transducer or an inductive hearing system, sends out an alternating magnetic field which is received by the telephone coil and which is then converted, in particular, into an audio signal. Compared to recording with a microphone, this is also advantageously interference-free, since interfering noises are usually not transmitted. “Free of disturbances” is understood in particular to mean “largely free of disturbances”. “Interference-free” is also understood to mean that the telephone coil is interference-free in those frequency ranges that are relevant for the magnetic field measurement, whereas, for example, the mains voltage at 50 Hz and its harmonics may be detected by the telephone coil. The telephone coil is also, in particular, already arranged in suitable proximity to the listener.

However, the concept of magnetic field measurement is advantageously not limited to a hearing aid with an integrated magnetic field sensor. Rather, in a second preferred embodiment, the magnetic field sensor is part of a test arrangement for a hearing aid. The test arrangement has a control unit and a test device which has a magnetic field sensor. The test arrangement is designed for testing a hearing aid, more precisely for characterizing a listener of the hearing aid. The hearing aid accordingly has a receiver for converting an electrical audio signal into a sound signal while generating a magnetic field. The control unit is designed in such a way that the magnetic field is measured by means of the magnetic field sensor, the listener is characterized in that the response behavior of the listener is determined on the basis of the measured magnetic field.

The magnetic field sensor is thus arranged outside the hearing aid, namely in or on the test device which, together with the control unit, forms the test arrangement. In a first suitable variant, the magnetic field sensor and the control unit are each part of a test device, i.e. the test device is identical to the test arrangement. In a likewise suitable second variant, on the other hand, the magnetic field sensor and the control unit are arranged separately from one another. The magnetic field sensor is then part of a test device, but the control unit is not. The control unit is, for example, a control unit of the hearing aid or a control unit of an additional external device.

The measurement itself does not fundamentally differ from the measurement with a magnetic field sensor in the hearing aid. To characterize the listener, the hearing aid is brought into the vicinity of the test arrangement, more precisely the test device, and a magnetic field measurement is then started. Such a test arrangement is particularly suitable for use by an audiologist, e.g. as part of a fitting session.

Examples of a test device which is identical to the test arrangement are a charging station or a base station for the hearing aid or a remote control. It is particularly advantageous to use a smartphone as a test device, which is expediently equipped with appropriate software in order to carry out the magnetic field measurement and the determination of the response behavior.

An embodiment is preferred in which the test device is an audio shoe, which is connected to the hearing aid in particular as an additional sensor. The audio shoe can be placed on the hearing aid, more precisely on its housing, and is worn by the user together with the hearing aid. The test device is designed as an adapter. In an advantageous embodiment, the test device is designed as an independent module and has a wireless system, i.e. a wireless system, in order to communicate with the hearing aid.

An embodiment is also particularly suitable in which the test device is a telephone coil shoe, which can be placed on the hearing aid as an adapter, and in which the magnetic field sensor is a telephone coil - in particular as described above - which is arranged in the telephone coil shoe. In this case, the control unit is preferably arranged outside the telephone coil shoe, that is to say not a part of it. The control unit is preferably a control unit of the hearing aid. The telephone coil shoe is designed in particular, similar to the audio shoe described above, as an adapter which retrofits the hearing aid with a telephone coil. The telephone coil shoe is worn by the user in particular during normal operation of the hearing aid.

Fig. 1

ein Hörgerät mit integriertem Magnetfeldsensor,

Fig. 2

eine Testvorrichtung mit Magnetfeldsensor und ein Hörgerät,

Fig. 3

unterschiedliches Antwortverhalten eines Hörers,

Fig. 4

Magnetfeldmessungen zu den Antwortverhalten aus Fig. 3, und

Fig. 5

Impedanzmessungen zu den Antwortverhalten aus Fig. 3.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. They each show schematically:

Fig. 1

a hearing aid with an integrated magnetic field sensor,

Fig. 2

a test device with a magnetic field sensor and a hearing aid,

Fig. 3

different response behavior of a listener,

Fig. 4

Magnetic field measurements to the response behavior Fig. 3 , and

Fig. 5

Impedance measurements to the response behavior Fig. 3 .

In Fig. 1 a hearing aid 2 is shown, which is used to supply a hearing-impaired user. The hearing aid 2 has a number of here two microphones 4, by means of which sound signals from the environment are picked up and converted into electrical audio signals A. The audio signals A are forwarded to a control unit 6, where they are modified, usually amplified, in accordance with the needs of the user. The modified audio signals A are passed on by the control unit 6 to a receiver 8, which converts the audio signals A back into sound signals S and outputs them.

In the present case, the hearing aid 2 is a BTE hearing aid, with a housing 10, which is worn by the user behind the ear, and with a sound tube 12, via which the sound signals S are conducted from the listener 8 to the ear. Alternatively, the hearing aid 2 is a RIC hearing aid in which the housing 10 is also worn behind the ear, but the receiver 8 is inserted into the ear and the sound tube 12 is then replaced by a cable. Again as an alternative, the hearing aid 2 is an ITE hearing aid which is inserted completely into the ear. Further alternative configurations for the hearing aid 2 are also suitable.

When operating the earphone 8, ie when converting an audio signal A into a sound signal S, a magnetic field M is generated, which in Fig. 1 is only sketchily drawn in for the purpose of visualization. The magnetic field M results from the general mode of operation of the earpiece 8, during the operation of which a time-varying electrical alternating field results, which corresponds to a time-varying current, which in turn generates the magnetic field M. The generated magnetic field M is measured by means of a magnetic field sensor 14. This then outputs a measurement signal U, U ′, for example a voltage that is proportional to the magnetic field M. On the basis of the measured magnetic field M, that is, by means of the measurement signal U, a response behavior V, V 'of the receiver 8 is determined and the receiver 8 is characterized thereby, or a warning signal is output, or both. For this purpose, the measurement signal U, U ′ is evaluated by the control unit 6, for example.

In the embodiment of Fig. 1 the magnetic field M is measured in the vicinity of the earpiece 8. However, this is not mandatory. Since each alternating electrical field naturally also generates a magnetic field M, a corresponding magnetic field M is also generated along an energy supply line 16 and in the vicinity of an energy supply 18. For an explicit representation of this effect in Fig. 1 was omitted for the sake of clarity. The power supply 18 is in Fig. 1 a battery. This is connected to the receiver 8 via the power supply line 16 in order to supply the receiver 8 with energy. Instead of arranging the magnetic field sensor 14 in the vicinity of the earpiece 8, the magnetic field sensor 14 is then arranged in an alternative not shown in the vicinity of the power supply line 16.

The magnetic field sensor 14 is in Fig. 1 for example a Hall sensor or a simple conductor loop. In an alternative not shown, a telephone coil which is integrated in the hearing aid 2 is used as the magnetic field sensor 14.

In Fig. 1 the magnetic field sensor 14 is integrated into the hearing aid 2. However, this is not mandatory for the underlying measurement principle. Hence shows Fig. 2 a variant in which the magnetic field sensor 14 is arranged outside the hearing aid 2, namely in a test device 20, which here is a charging station or a base station for the hearing aid 2 and at the same time forms a test arrangement for the hearing aid 2. The test device 20 has a control unit 6 to which the magnetic field sensor 14 is connected. The measurement itself does not fundamentally differ from the measurement with a magnetic field sensor 14 in the hearing aid 2. To characterize the listener 8, the hearing aid 2 is brought into the vicinity of the test device 20, for example as in FIG Fig. 2 is inserted, a sound signal S is output via the receiver 8 and a magnetic field measurement is then started.

The characterization of the listener 8 is based on the knowledge that the magnetic field M generated by the listener 8 also reflects the response behavior V, V 'of the listener 8. The response behavior V, V 'is largely defined by the output power and this power and the magnetic field M are each directly dependent on the current which is supplied to the earpiece 8. In addition to the dependence on the audio signal A, the response behavior V, V 'is also dependent on the specific environment in which the earphone 8 is located, especially the installation situation, ie how and where the earphone 8 is mounted in the hearing aid 2 and with what other components the handset 8 is connected. For example, the type and length of the sound tube 12 determine the response behavior V, V '. Furthermore, the response behavior V, V 'is also dependent on the specific use of the hearing device 2 by a user, in particular on the individual wearing method and the likewise individual degree of coupling between the earpiece 2 and the user's ear. In addition, the response behavior V, V 'is also time-dependent insofar as the environment and the installation situation can change over time, for example due to a progressive clogging of the earpiece 8 or the sound tube 12 with cerumen or an exchange of the sound tube 12 or by others Effects.

In Fig. 3 two response behaviors V, V 'are shown as examples. The respective response behavior V, V 'is defined by the ratio of the powers of the audio signal A and the resulting sound signal S. The response behavior V, V' accordingly indicates the output power of the listener 8 for a given input power. The response behavior V, V 'is frequency-dependent, ie audio signals A of the same strength but different frequencies are converted into sound signals S of different strengths under certain circumstances. In Fig. 3 the respective response behavior V, V 'was determined by converting audio signals A with the same power but different frequencies by means of the receiver 8 and plotting the power of the resulting sound signal S on the Y-axis against the frequency on the X-axis. The two graphs have been generated for sound tubes 12 of different lengths. It can be clearly seen that the length of the sound tube 12 has the response behavior V, V ' changes. In Fig. 3 this can be seen particularly on the basis of the local maxima. As a result, the response behavior V 'is changed compared to the response behavior V, and some of the local maxima are clearly shifted towards higher frequencies. If, for example, the response V leads to a specific and desired output characteristic of the hearing aid 2 as a whole, it becomes clear that the changed response V ′ must lead to a correspondingly modified output characteristic given the same control of the earpiece 8 by the control unit 6. The desired response behavior V is therefore set as the target response behavior at the beginning, for example in a fitting session, and then compared with the then present and possibly deviating response behavior V 'during normal operation of the hearing aid or in a further fitting session. With knowledge of the two response behaviors V, V ', their difference is then determined and the control of the receiver 8 is changed in such a way that the resulting response behavior V corresponds to the target response behavior. A change is brought about, for example, by additionally modifying the audio signals A by means of the control unit 6.

In Fig. 4 is a simulation of the measurement signal U, U 'for the respective magnetic field M of the two responses V, V' from Fig. 3 . In the present case, the hearing aid 2 has a telephone coil which is used as a magnetic field sensor 14, and Fig. 4 shows the measurement signals U, U ′ which are generated by the magnetic field sensor 14. The differences between the two measurement signals U, U 'and their correlation to the response behavior V, V' can be clearly seen. In particular, the measurement signals U, U 'each represent the first derivative of the respective response behavior V, V'.

For comparison, in Fig. 5 a simulation of impedance measurements I, I 'for the two responses V, V' Fig. 3 shown. It can be clearly seen that the signal strength, which is plotted on the Y-axis in each case, in Fig. 4 is significantly larger. The dynamics of the measurement signals U, U 'is accordingly significantly greater than the dynamics of the impedance measurements I, I'. The magnetic field measurement therefore leads to a significantly more precise result, even the smallest changes can still be measured reliably.

In an embodiment not shown, the response behavior V, V ′ is parameterized by means of an adaptive filter, which is a component of the control unit 6, for example. The magnetic field M is measured and, as a function of this, a measurement signal U, U 'is generated, which is fed to the filter as a filter input signal. The filter has a filter function which is parameterized by a number of filter parameters. The measurement signal U, U 'is now fed to the filter as a filter input signal, whereupon the filter automatically adapts the filter function to the filter input signal in order to map it. The filter parameters are changed accordingly. The filter automatically adjusts and changes the filter parameters. The filter parameters therefore change with a change in the magnetic field M, ie also with a change in the response behavior V, V ', so that the response behavior V, V' is advantageously parameterized by means of the filter parameters and is thereby also determined. Instead of measuring the response behavior V, V 'in detail, only the filter parameters are used to determine the response behavior V, V'.

List of reference symbols

2

Hearing aid

4th

microphone

6th

Control unit

8th

Listener

10

casing

12th

Sound tube

14th

Magnetic field sensor

16

Power supply line

18th

power supply

20th

Test device

A.

Audio signal

I, I '

Impedance measurement

M.

Magnetic field

S.

Sound signal

U, U '

Measurement signal

V, V '

Response behavior

Claims (13)

1. Method for characterizing a receiver (8) in a hearing device (2),

   - wherein the receiver (8) is embedded in an environment and has a response behavior (V, V'), which is influenced by the environment and which indicates which output power the receiver (8) has for a given input power,

   - wherein the receiver (8) converts an electrical audio signal (A) into a sound signal (S) and thereby generates a magnetic field (M),

   - wherein the magnetic field (M) is measured by means of a magnetic field sensor (14),

   - wherein the receiver (8) is characterized by determining the response behavior (V, V') of the receiver (8) on the basis of the measured magnetic field (M).
2. Method according to the preceding claim,
   characterized in
   that the environment is determined by an installation situation of the receiver (8) and has an element, which is a component of the hearing device (2), wherein the component is connected to the receiver (8) and influences the response behavior (V, V').
3. Method according to one of the preceding claims,
   characterized in
   that the environment is determined by a usage situation of the receiver (8), wherein the usage situation determines the response behavior of the receiver (8) and is selected from a set of situations comprising: a wearing mode of the hearing device (2), a degree of coupling between the receiver (8) and an ear of the user, a degree of clogging by earwax.
4. Method according to one of the preceding claims,
   characterized in
   that the response behavior (V, V') is compared as an actual response behavior with a desired response behavior, wherein a difference is determined between the actual response behavior and the desired response behavior and the hearing device (2) is adjusted based on the difference.
5. Method according to the preceding claim,
   characterized in
   that the hearing device (2) is adjusted by modifying the audio signal (A) by means of the control unit (6) in such a way that the difference is at least partially compensated.
6. Method according to one of the preceding claims,
   characterized in
   that the response behavior (V, V') is compared as an actual response behavior with a desired response behavior, wherein a difference is determined between the actual response behavior and the desired response behavior, and a warning signal is output as a function of the difference.
7. Method according to one of the preceding claims,
   characterized in
   that the response behavior (V, V') is parameterized by means of an adaptive filter by measuring the magnetic field (M) and, as a function thereof, generating a measurement signal (U, U'), which is fed to the filter as a filter input signal.
8. Method according to one of the preceding claims,
   characterized in
   that the magnetic field sensor (14) is arranged directly at the receiver (8), in particular at a distance of at most 3 cm from the receiver (8), and that the magnetic field (M) is measured directly at the receiver (8).
9. Method according to one of the preceding claims,
   characterized in
   that the hearing device (2) has a power supply (18), which is connected to the receiver (8) by means of a power supply line (16), for supplying power to the receiver (8), and that the magnetic field sensor (14) is arranged directly at the power supply line (16), in particular at a distance of at most 5 mm from the power supply line (16), and that the magnetic field (M) is measured directly at the power supply line (16).
10. Method according to one of the preceding claims,
    characterized in
    that the hearing device (2) has a telecoil, which is used as the magnetic field sensor (14).
11. Hearing device (2), which has a receiver (8), for converting an electrical audio signal (A) into a sound signal (S) under generation of a magnetic field (M), and which has a magnetic field sensor (14), and which has a control unit (6) that is designed in such a way that

    - the magnetic field (M) is measured by means of the magnetic field sensor (14),

    - the receiver (8) is characterized by determining a response behavior (V, V') of the receiver (8) on the basis of the measured magnetic field (M), wherein the response behavior (V, V') indicates which output power the receiver (8) has for a given input power.
12. Test arrangement, which is designed for testing a hearing device (2) and which has a control unit (6) and a test device (20) that has a magnetic field sensor (14), wherein the hearing device (2) has a receiver (8), for converting an electrical audio signal (A) into a sound signal (S) under generation of a magnetic field (M), wherein the control unit (6) is designed in such a way that

    - the magnetic field (M) is measured by means of the magnetic field sensor (14)

    - the receiver (8) is characterized by determining a response behavior (V, V') of the receiver (8) on the basis of the measured magnetic field (M), wherein the response behavior (V, V') indicates which output power the receiver (8) has for a given input power.
13. Test arrangement according to the preceding claim,
    characterized in

    that the test device (20) is a telecoil shoe, which can be placed as an adapter on the hearing device (2), and

    that the magnetic field sensor (14) is a telecoil, which is arranged in the telecoil shoe.

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