EP3567874B1 - Hearing device and method for operating a hearing device - Google Patents

Description

The invention relates to a method for operating a hearing device and a corresponding hearing device.

In the most general embodiment, a hearing aid has a microphone, signal processing and a receiver, the receiver also being referred to as a loudspeaker. A hearing device is used, for example, to care for a hearing-impaired user and to compensate for a hearing loss. The microphone generates an input signal from sound signals in the environment, which is fed to the signal processing. The signal processing modifies the input signal and thereby generates an output signal, which is therefore a modified input signal. To compensate for a hearing loss, the input signal is amplified with a specific amplification factor, for example. Finally, the output signal is output by means of the earphone, in which the latter converts the output signal into a sound signal. The input signal and the output signal are electrical signals, which are therefore also referred to as signals for short. In contrast, the sound signals from the environment and the sound signal emitted by the listener are acoustic signals.

A hearing aid is typically either monaural and worn on only one side of the head or binaural and then has two individual devices that are worn on different sides of the head. Depending on the type, the hearing aid is worn on, in or behind the ear or a combination of these. Common types of hearing aids include BTE, RIC, and ITE hearing aids. These differ in particular in their design and carrying method.

In principle, it is possible with a hearing aid to use a so-called beamformer in order to realize directional hearing, i.e. to prefer sound signals from a certain direction relative to other sound signals and to amplify them more, i.e. to emphasize them. For this purpose, a directional microphone is used, which is usually a microphone array made up of at least two microphones. The directional microphone is housed in the hearing aid and picks up the sound signals from the environment in two different positions. Accordingly, several input signals are generated, which are then suitably combined by the signal processing in order to achieve a directivity, i.e. to align the beamformer in a certain direction and then to emphasize sound signals from this direction. For example, a speaker in the front area of the user is amplified in this way compared to the rest of the environment, which improves speech intelligibility.

The problem is using a beamformer in environments that are more demanding than those that only have one relevant sound source. In environments in which potentially relevant sound signals and in particular information for the user can arrive from several directions, such relevant sound signals are sometimes suppressed because the beamformer is already directed at another sound source. In the above example with the speaker in the front report, the user's back area is strongly suppressed relative to the front area, so that sound sources in the back area can only be perceived poorly or not at all by the user.

In the EP 2 544 462 A1 a binaural hearing aid system is described which has a compressor. In at least one frequency channel of the compressor, the gain of the compressor is controlled by a compressor control signal, which is a function of a signal level and a signal parameter of the hearing aid.

In the EP 2 544 463 A1 a binaural hearing aid system is described, with two hearing aids, each of which has a compressor. The gain of the compressor of one hearing aid is controlled with a signal, with a Value which is essentially identical to the value of a signal that controls the gain of the compressor of the other hearing aid.

Against this background, an object of the invention is to improve the emphasis of sound signals from a specific direction in a hearing aid, and thus in particular the speech intelligibility, while suppressing other potentially relevant sound signals as little as possible in order to be able to continue to perceive potentially relevant sound signals from other directions . To this end, a method for operating a hearing device and a corresponding hearing device are to be specified.

The object is achieved according to the invention by a method with the features according to claim 1 and by a hearing device with the features according to claim 9. Advantageous refinements, developments and variants are the subject matter of the dependent claims. The statements made in connection with the method also apply to the hearing device and vice versa.

The method is used to operate a hearing device. In operation, the hearing device is worn in particular by a user. The hearing device first generates an input signal from sound signals from the environment. For this purpose, the hearing device has at least one microphone, which picks up the sound signals and converts them into the ambient signal. Furthermore, the hearing device has a signal processor which is designed to modify the input signal and thereby generate an output signal. The hearing aid also has an earphone for outputting the output signal, ie for converting the output signal into a sound signal which is output to the user. In particular, only one output signal is generated for each receiver of the hearing device. In the case of a monaural hearing aid, only one output signal is therefore generated. In a binaural hearing aid, two output signals are generated, one for each side of the user's head. The input signal is modified in particular with regard to a specific hearing profile of the user. In a preferred embodiment, the hearing aid is a hearing aid for fitting to a hearing-impaired user, and the hearing profile deviates from the hearing profile of a person with normal hearing because of a hearing impairment away. To this extent, the input signal is modified in such a way that the hearing damage is at least partially, preferably completely, compensated. The input signal is usually amplified for this purpose. In particular, a respective output signal is therefore adapted to the hearing profile of the user on the respective ear

To modify the input signal, the signal processing has an automatic gain control (AGC for short, ie automatic gain control), which has a compressor that can be operated with a compression scheme. The environment of the user is now divided into several directions, one of which is determined as a relevant direction by means of a direction determination unit is selected. The relevant direction is to be emphasized in relation to other directions, so that sound signals from the relevant direction are emphasized in that these sound signals from the relevant direction experience greater amplification relative to other sound signals. For this purpose, the input signal is modified depending on the direction by operating the compressor with a compression scheme that is adjusted depending on the relevant direction, so that sound signals from the relevant direction are emphasized compared to sound signals from other directions. The information about the direction in which a relevant sound source is located is used to selectively modify the input signal and reproduce this sound source more clearly for the user. In the process, a sound source is not specifically selected and specifically amplified in a certain direction; rather, a directional effect results automatically from the fact that the compression scheme is adapted to the sound source in the relevant direction, and thus precisely this sound source and thus the associated direction are selectively emphasized . In the case of a binaural hearing aid, this is preferably carried out equally on both sides.

The relevant direction is selected according to its relevance to the user. A direction is particularly relevant when there is a sound source of a certain type, e.g. a speaker, or when the sound source has a higher volume relative to other sound sources in the same direction, ie a higher level, e.g. a speaker in a crowd. The direction determination unit is used to determine and in particular also to select the relevant direction. In a suitable embodiment, the direction determination unit analyzes the input signal and uses it to determine the direction in which a sound source that is relevant to the user is located, so that this direction is then selected as the relevant direction. In an advantageous embodiment, the hearing device and specifically the direction determination unit has a classifier for this purpose in order to assign sound sources in the area to a specific type, so that that direction is then selected as a relevant direction in which a sound source of a specific type is located.

In principle, it is possible to achieve the effect described above, although not identically, but to some extent with a beamformer, which strengthens a specific direction compared to other directions and correspondingly suppresses the other directions through a suitable combination of several input signals. This results in the disadvantages already mentioned at the outset. More suitable is a configuration that at least temporarily averts these disadvantages by only switching on the beamformer in certain situations and activating it depending on the ambient noise level, i.e. depending on how strong the ambient noise is compared to useful signals. This is indicated by the signal-to-noise ratio, SNR for short (signal-to-noise ratio). If the SNR is high, the beamformer is deactivated so that sound signals from unexpected directions, especially from the back area, i.e. from behind, are not accidentally suppressed. This is based on the consideration that, with a high SNR, no beamformer is required to increase speech intelligibility and its use is therefore dispensed with. With a comparatively low SNR, the beamformer is then activated and directed at a sound source that is relevant to the user, e.g. a speaker in the front area of the user, i.e. in front. The beamformer is now used to achieve high speech intelligibility despite the low SNR. It is essential here that the beamformer is only activated in special situations, i.e. as required. In the cases in which the beamformer is activated, however, this still happens as described at the expense of sound signals from other directions, which are then suppressed together with the background noise and possibly unintentionally.

The principle-related strong suppression of sound signals from directions other than the relevant direction in a beamformer—as described—is to be avoided in the present case. Therefore, to improve the emphasis of a certain direction, more precisely of one or more sound signals from this direction, not the directivity of a beamformer is used, but an automatic gain control, AGC for short. An AGC is particular characterized in that it performs a level-dependent modification of the input signal in order to generate the output signal in such a way that it is matched as optimally as possible to the user's hearing profile and in particular to hearing impairment. In particular, the AGC is a part of the signal processing of the hearing aid. For level-dependent modification, an AGC generally has a compressor which controls the amplification of the input signal as a function of its level, ie the input level, and in connection with a specific compression scheme. The compression scheme specifies what amplification factor is used for the input signal at a given input level. The compression scheme is parameterized by one or more compression parameters, preferably one or more knee points, one or more compression ratios for one or more specific level ranges of the input level, a switch-on time (also referred to as attack), a switch-off time (also referred to as release) or a combination thereof . A knee point indicates a transition between two level ranges with different compression ratios.

The compressor of the AGC is now operated depending on the direction with a suitable compression scheme, so that the sound signals from different directions are compressed differently. In this respect, the concept proposed here represents an alternative to a beamformer, but can in principle also be used profitably in combination with a beamformer. In the present case, the environment around the user is divided into a number of directions and the compressor is set in such a way that sound signals from the relevant direction, ie relevant sound signals, are emphasized for the user. Depending on which sound source is in which direction, a correspondingly suitable compression scheme is selected and set. In this way, a classically strong directional effect is initially expediently dispensed with and instead an advantageously gradual adaptation of the modification of the input signal is carried out.

By selecting an appropriate compression scheme, one of the directions is then selectively emphasized, preferably around in that direction to selectively increase speech intelligibility without causing suppression in the other directions at the same time. In this respect, a directional effect is generated by means of the compressor and generally by means of the AGC in such a way that a relevant sound source is emphasized in a specific direction by a special compression scheme in that same direction. In this case, the emphasis is realized in particular by the selection of a suitable compression scheme, which is tailored to the sound source to be emphasized, so that other sound sources fade into the background relative to it, but are not completely suppressed. This advantageously achieves a reduced directivity in comparison to a beam former, and overall a compromise is found between the strongest possible emphasis in one direction and the weakest possible suppression in the other directions. If the front area is emphasized, for example, the user can continue to hear sound signals from the back area.

A key concept here is direction-dependent compression to emphasize sound sources from a specific direction. In other words: a direction-dependent parameterization of the compressor is carried out. As a result, a gradual directivity is advantageously achieved by means of the compressor and generally by means of the AGC. Using the AGC, one or more sound sources are emphasized in a certain direction. In addition, it is possible to achieve a corresponding directional effect in several directions at the same time, so that the usual limitation of a beamformer to just one emphasized direction is advantageously eliminated.

A configuration is particularly preferred in which the direction determination unit has a beam former which is used to determine the relevant direction. This is based on the idea that a beamformer is specially designed to generate directional signals and is therefore particularly suitable for dividing the environment into several directions. For this purpose, the input signal is fed to the beamformer and then processed for each of the directions in such a way that a directed input signal is generated for each of the directions, which only or at least predominantly consists of sound signals results from a single direction. Each directional input signal is thus assigned to one of the directions. The directional input signals are then each examined for the presence of a sound source relevant to the user, eg by means of an additional classifier or simply based on a signal property of the directional input signal, eg its level or its SNR. The direction of that directional input signal which contains a relevant sound source is then selected as the relevant direction. The compression scheme is then adjusted in such a way that the same sound source is emphasized, so that the relevant direction is also emphasized as a result. The beamformer is therefore initially used advantageously to subdivide the environment into different directions and to determine the relevant direction. In contrast, the beamformer is not used to generate an output signal that would also be directed by a combination of the directed input signals. Rather, this function results from the special control of the compressor.

The beamformer generates the directed input signals, in particular from a number of input signals, which are correspondingly generated by a number of microphones, which each convert the sound signals from the environment into a respective input signal. The microphones are arranged at different positions on the hearing aid and in this way form a microphone array. In this respect, the various input signals can also be viewed as a single input signal, which is generated by the microphone array. To generate the individual directional input signals, the input signals of the various microphones are suitably combined with one another by the beamformer. In a preferred embodiment, the microphone array has two microphones and the beamformer generates four directional input signals for the four directions front, back, left and right. However, other configurations are conceivable and also suitable.

The directed input signals, which are generated by the beamformer, do not have to be used to generate the output signal. In a suitable embodiment, the directed input signals are used rather only to determine the relevant direction and the AGC and especially the compressor act on the input signal as a whole. In an advantageous variant, on the other hand, the directional input signals are fed to the AGC, in particular instead of the input signal itself, and are processed separately from one another by means of the AGC in order to implement direction-dependent compression. In this case, the AGC and especially the compressor affect individual parts of the input signal, namely the directional input signals, which represent the input signal divided according to direction, separately and independently of one another. The separately processed directional input signals are then finally mixed together to form an output signal. Preferred configurations of both concepts are presented in more detail below. In principle, the various configurations or parts thereof can also be combined with one another. The explanations for a special embodiment apply analogously to the other embodiments.

In a particularly simple and advantageous embodiment, the compression scheme is defined by at least one compression parameter, in particular as described above, and the compression scheme is set depending on the relevant direction by changing the compression parameter depending on the relevant direction. In a first variant, there is only a switchover between at least two discrete values. In a second variant, on the other hand, the compression parameter is continuously changed, i.e. continuously adjusted. In this embodiment, a respectively suitable parameterization for the compressor is selected and set as a function of the direction, and the compression of the input signal is controlled accordingly.

In one embodiment, the compressor has a number of instances that are operated with different instance schemes. These instance schemes are inherently compression schemes as described above. A respective instance scheme is now designed to emphasize a specific type of sound signal, eg to emphasize speech or sound, eg music. In this context, the instances are referred to as compression instances. The input signal is respectively the multiple Instances supplied, which then generate a corresponding number of modified input signals, which are then combined together to form the output signal. In principle, the same input signal is used for all instances, so that the compressor acts on the entire input signal as a whole. It is now essential that a proportional ratio of the modified input signals to one another in the output signal is set as a function of the relevant direction, so that the compression scheme is set as a mixture of the instance schemes. Different versions of the input signal are therefore mixed depending on the direction, ie depending on the relevant direction, one or the other instance has more or less influence on the output signal. Mixing, also merging or combining, is expediently carried out by means of a mixer, which then generates the output signal.

A particular advantage of this embodiment is that the individual instances can each be operated with a fixed instance scheme and are preferably also operated, and yet there is an overall changeable compression scheme. The input signal is processed differently in parallel by means of the individual instances, so that the compression scheme of the compressor as a whole is then adjusted by suitably selecting and adjusting the proportion of the modified input signal. In a first variant, there is a switch between two discrete proportions, in a second variant, on the other hand, the proportion is continuously changed. In order to set or change the proportional ratio, for example, the level of the input signal before the respective entity is changed accordingly, or alternatively or additionally the level of the respective modified input signal after the respective entity.

An advantage of the above-mentioned embodiment consists in particular in the fact that the instances can be operated with a predefined, ie a fixed instance scheme and are preferably also operated, so that the respective instance scheme itself is not changed during operation. The instances are therefore dedicated instances for different types of sound signals. In an also suitable As a variant, however, the individual instances can also be set, ie they have a changeable parameterization, which is then changed during operation, so that the instances are then dynamic rather than static, as described above.

In a further refinement, the input signal has a number of directed, i.e. direction-dependent, input signals which are each assigned to one of the number of directions. The compressor now has an instance for each of the directed input signals, which is operated with a respective instance scheme. In this context, the instances are also referred to as directional instances and the instance schemes as directional schemes. The instance schemes are inherently compression schemes as described above. A respective instance is supplied with one of the directional input signals, so that the compression scheme is set as a mixture of the instance schemes. In principle, the statements regarding the previously mentioned embodiment with multiple compression entities also apply to the embodiment with multiple directional entities, with the difference that a single directional entity is not supplied with the entire input signal, but with a processed input signal, which is then modified . In this way, only a specific directional component of the input signal is modified by means of a respective direction instance, so that the individual directions are thus processed independently of one another in an optimal manner by means of the AGC.

A particular advantage of the aforementioned configuration with a plurality of instances, specifically direction instances, is in particular that it is possible to react separately in each direction to the situation specifically present there, and this is preferably also the case. In an advantageous development, a respective instance scheme for the respective directed input signal is set for each of the directions as a function of a type of sound signal in the assigned, ie the associated direction. In other words: for a given direction, it is determined whether there is a sound source that emits sound signals of a specific type, eg speech or music. In addition, the guy will determined, for example by means of a classifier. Depending on the type of sound signal, a corresponding instance scheme is then set for the instance.

Due to the subdivision into different directions in connection with the possibility of using different compression schemes for these, i.e. more precisely instance schemes, the directions can advantageously also be processed independently of one another and are expediently modified as required. The directed input signals are preferably generated by means of a beam former. A beamformer is characterized by the fact that it emphasizes sound signals from a specific direction, so that a beamformer is suitable for generating directional input signals. For this purpose, the beamformer is applied in particular to each of the multiple directions in order to then generate an associated directed input signal for each of these directions. With a conventional beamformer, only a direction-dependent input signal would be used and, after modification, output as an output signal. In contrast, in the present case, the plurality of directional input signals in the different directions are modified in each case by means of the AGC, with the result that input signals compressed in a direction-dependent manner are generated. These are then combined into an output signal and finally output.

The configurations with several directional instances and the configuration with several compression instances are combined with one another in one configuration. For example, in such a way that a respective directional instance is composed of several compression instances, so that a single directional input signal is then modified, for example, with different fixed instance schemes and the different modified directional input signals are then mixed together to form the output signal.

Equivalent to the chosen formulation with several instances of the compressor, one can also speak of an AGC with several AGC instances, which then each have one or several correspondingly designed compressors exhibit. These different formulations are regarded as equivalent and differ at most in particular in the specific circuit implementation, but not in the functionality achieved, which is particularly important here.

The compression scheme, in particular the instance scheme, which is set, is preferably selected from a set of compression schemes, comprising: a speech scheme for emphasizing speech components, a sound scheme for adapting only to a hearing profile of a user of the hearing aid. As a result, there is advantageously a switching between a voice scheme, which is designed for the best possible speech intelligibility, and a sound scheme, which is designed for a reproduction of the sound signals from the environment that is as true to nature as possible. When using the speech scheme, speech is thus emphasized by the compression, whereas with the sound scheme the environment itself is emphasized, in particular without special consideration of individual sound sources or individual types of sound signals. This results in a particularly realistic sound reproduction, which is particularly advantageous in the case of music as a sound signal.

The particularly important case of the presence of speech in the environment is taken into account by the possibility of selecting the speech scheme. In order to make such speech, ie a sound signal from a speaker, as easy as possible for the user to understand, a compression scheme is set which improves speech intelligibility. Here, the realistic reproduction of other sound signals or noises is of secondary importance; instead, speech is primarily made recognizable for the user. Conversely, in an environment without speech, it is expedient to strive for a reproduction of the acoustic environment that is as realistic as possible, i.e. the best possible sound quality should be achieved. This is realized by the possibility of selecting the sound scheme. The best possible sound quality is understood in particular to mean that hearing damage to the user is compensated for as optimally as possible, ie maximum hearing loss compensation is carried out. This is particularly important for music, which may be severely distorted by a compression scheme used to improve speech intelligibility. The same applies to other sound signals in the environment, which are sometimes distorted to such an extent that they are no longer recognizable to the user and can no longer be assigned.

A particular advantage of direction-dependent compression is that it circumvents the problem that a single compression scheme designed for a specific situation, e.g. speech or sound, is not optimal in an environment in which both speech and other sound signals, especially music, available. In a particularly advantageous embodiment, the environment is divided into several directions as part of the direction-dependent compression and the sound signals of a respective direction are each modified with an optimal compression scheme, i.e. one that is matched to the respective sound signals. Thus, instead of analyzing the entire environment as a whole and performing the same compression on the environment as a whole, a corresponding consideration is performed separately for each of the multiple directions.

Expediently, the input signal is only modified in a direction-dependent manner if a directed sound signal is detected in the surroundings, and otherwise the input signal is modified in a direction-independent manner, ie all directions are modified in the same way. In other words, the hearing aid has a basic operation in which none of the directions are specially emphasized by adjusting the compressor. In principle, therefore, there is also the possibility that none of the directions is a relevant direction and accordingly no relevant direction can be selected, ie the determination fails. In general, in the event that no relevant sound source or no relevant sound signal is or cannot be determined in a respective direction, ie if no relevant sound signal is present, a basic scheme is preferably used as a compression scheme for this direction. In basic operation, the basic scheme is then used for each direction. The basic scheme is advantageously the sound scheme described above, which a particularly lifelike reproduction of all sound signals in the environment as a whole is guaranteed. If there is no special sound signal in one direction, the type of sound signal that results is in particular the "background" type.

In a suitable embodiment, several directions are each selected as a relevant direction. This is made possible in particular by the special direction-dependent compression. In contrast, only a single direction can typically be emphasized with a beamformer alone. In the present case, however, several directions can be selected as relevant directions at the same time. In this way, for example, several speakers in the area are advantageously highlighted for the user. Alternatively or additionally, suddenly occurring warning or alarm signals are emphasized without suppressing other relevant sound signals.

The different directions are preferably regions that result from dividing the environment into sectors based on the user. The user of the hearing device forms a center point in the area, starting from which the area is divided into a number of sectors, ie angular sections. Each region corresponds to a sector and the sectors line up around the user. In a particularly useful embodiment, the environment is divided into exactly four directions, namely front, back, left and right. This directional information relates to the user's viewing direction, so that "in front" designates a front area, "rear" a back area and "left" and "right" a left or right side area. In particular, each of the four directions includes an angular section of 90°. The environment is thus divided into four quadrants. A subdivision into only two regions, for example front and back, ie a front area and a back area, is also suitable in principle. In one variant, a subdivision into regions does not only take place in one plane, but in space. In this case, in an expedient embodiment, an additional region is formed towards the top. Accordingly, an additional downward region is also advantageous.

A hearing aid according to the invention is designed to carry out the method described above. In particular, the hearing device has a signal processor that is designed to carry out the method. The hearing device is either monaural or binaural, has one or two individual devices that are worn in or on the ear. The hearing device is used in particular to care for a hearing-impaired user. The hearing aid has at least one microphone and at least one earphone, with each individual device of the hearing aid, more precisely, having at least one, preferably a plurality of microphones and an earphone. Each individual device has its own housing in which the associated microphones are housed. Depending on the type of hearing aid, the receiver is also accommodated in the housing or at least connected to the housing via a feed line. Each individual device also has an earpiece that can be inserted in particular into the user's ear in order to output the sound signals that the earpiece generates from the output signal to the user there. The hearing device expediently has a battery for supplying energy, with each individual device advantageously having its own battery, which is accommodated in particular in the housing.

Fig. 1

ein Hörgerät,

Fig. 2

ein Blockschaltbild eines Hörgeräts,

Fig. 3

ein Blockschaltbild eines weiteren Hörgeräts,

Fig. 4

ein Kompressionsschema,

Fig. 5

eine Unterteilung einer Umgebung in mehrere Richtungen,

Fig. 6

einen Kompressor mit mehreren Instanzen.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The above general explanations apply mutatis mutandis to the specific exemplary embodiments shown below. The drawing shows schematically:

1

a hearing aid,

2

a block diagram of a hearing aid,

3

a block diagram of another hearing aid,

4

a compression scheme,

figure 5

a subdivision of an environment in several directions,

6

a compressor with multiple instances.

1 shows an exemplary embodiment of a hearing aid 2. The hearing aid 2 has a signal processing unit 4. FIG. The hearing device 2 is either monaural or binaural, ie it has one or two individual devices that are worn in or on the ear. In 1 only a single device is shown. In the present case, the hearing device 2 is used to supply a hearing-impaired user N. The hearing device 2 has at least one microphone 7 and at least one earphone 6 . This in 1 The individual device shown as an example has two microphones 7 and a receiver 6, which is arranged here externally with respect to a housing 8, so that the hearing device 2 shown is a so-called RIC device.

The signal processing 4 is designed for direction-dependent compression. Two embodiments are in the 2 and 3 shown. These each show a block diagram of a hearing device 2 . The signal processing 4 generally has an automatic gain control 10 , AGC for short, which in turn has a compressor 12 . The signal processor 4 also has a direction determination unit 14, by means of which the compressor 12 is controlled. For this purpose, the direction determination unit 14 determines a relevant direction R, depending on which the compressor 12 is controlled.

An input signal E, which is generated by a microphone 7 , is generally fed to the signal processor 4 . The input signal E is then fed to the AGC 10, which modifies the input signal E and forwards it as an output signal A to the earphone 6 for output. In the present case, the input signal E is also used to determine the relevant direction R, ie to determine the direction, and is supplied to the direction determination unit 14 for this purpose. The compressor 12 is then adjusted as a result of the direction determination. The behavior of the compressor 12 is defined by a compression scheme K, which is then changed as a function of the relevant direction R in order to achieve an emphasis of a relevant sound source in this direction.

A compression scheme K is an example in 4 shown, here in a representation as gain G as a function of an input level EP, ie a level of the input signal E. The compression scheme K shown has a knee point 16 which defines two level ranges with different compression ratios. A constant amplification is carried out on a lower level range, on an upper level range the amplification is reduced as the input level increases. The compression scheme is now changed as a function of the relevant direction R, for example by shifting the knee point 16 in order to bring about a changed behavior of the compressor 12.

The environment of user N is divided into several directions, e.g. as in figure 5 shown in four directions "front" V, "back" H, "left" L and "right" S. Of these directions, one is selected as a relevant direction R by means of the direction determining unit 14 and is then to be emphasized over the other directions. For this purpose, the input signal E is modified as a function of the direction, in that the compressor 12 is operated with a compression scheme K, which is set as a function of the relevant direction R. The information about the direction in which a relevant sound source is located is therefore used in order to selectively modify the input signal E and to reproduce this sound source more clearly for the user N.

The relevant direction R is selected according to its relevance for the user N. A direction is particularly relevant when there is a sound source of a certain type, e.g. a speaker, or when the sound source has a higher volume relative to other sound sources in the same direction, ie a higher level, e.g. a speaker in a crowd. To determine the relevant direction R, the input signal E is analyzed by the direction determination unit 14 and used to determine the direction in which a sound source that is relevant for the user N is located, so that this direction is then selected as the relevant direction R. For example, the hearing aid 2 has a classifier (not shown) for this purpose, in order to assign sound sources in the area to a specific type, so that then that direction is selected as a relevant direction R, in which a sound source of a certain type lies.

In 2 an input signal E is now generated by a single microphone 7 and fed to the compressor 12 and the direction determination unit 14 . The direction determination unit 14 uses the input signal E to determine a relevant direction R and thus controls the compressor 12 in that the compression scheme K is changed as a function of the relevant direction R. As a result, a modified input signal Emod is generated depending on the direction, which is then output as output signal A via the earphone 6 .

In 3 the direction determination unit 14 has a beamformer which generates a plurality of directional input signals Eger from an input signal E from a plurality of microphones 7, ie the input signal E breaks down into a plurality of directional input signals Eger. In this case, each of the directed input signals Eger is assigned to one of the directions and is therefore generated solely or at least predominantly from sound signals from this one direction. The directed input signals are then fed to the compressor 12 and modified there separately, so that a plurality of modified input signals Emod are generated, which are then combined to form the output signal A.

A possible configuration of a compressor 12 suitable for this is shown in 6 shown. The compressor 12 shown there has a plurality of instances 18, each of which is supplied with one of the directed input signals Eger. These entities 18 are therefore also referred to as directional entities. In addition, each entity 18 is operated with its own entity scheme, which is set depending on the relevant direction R. As a result, each directional input signal Eger is modified separately and accordingly a separate compression scheme, namely the respective instance scheme, is used for each direction, so that the sound signals of each individual direction are optimally compressed independently of the sound signals of the other directions. The modified input signals Emod are then mixed together in a mixer 20. In this case, in particular, a proportion of the modified input signals Emod is suitably set at the output signal A in such a way that an optimal compression scheme K results overall.

In 7 a compressor 12 is shown, which has a plurality of instances 18, to which the complete input signal E is supplied in each case. In contrast to 6 , where each instance 18 is supplied with a different signal, namely a directed input signal Eger, each of the instances 18 in 7 the same signal, in this case the input signal E is supplied. The individual instances 18 are operated with different instance schemes, so that the input signal E is modified differently in each instance 18 and different modified input signals Emod result, which are then combined in a mixer 20 to form the output signal. In this case, the individual instances 18 are also referred to as compression instances. In contrast, several or all instances are 18 in 6 If necessary, also operated with the same instance scheme. The different instance schemes in 7 are designed for different sound sources and generally different situations, one of the instance schemes is a speech scheme for emphasizing speech, and the other instance scheme is a sound scheme, which reproduces sound signals from the environment as realistically as possible and adapted to the hearing impairment of the user N.

The statements of 6 and 7 are combined in a variant that is not shown in such a way that instead of each of the instances 18 in 6 a respective directional input signal Eger several instances 18 as in 7 is supplied in order to realize, for example, a mixture of different instance schemes for a single direction. For the specific case of 6 and 7 the compressor 12 would then have eight instances, namely one instance with speech scheme and one with sound scheme for each direction.

Reference List

2

hearing aid

4

signal processing

6

listener

7

microphone

8th

Housing

10

automatic gain control, AGC

12

compressor

14

direction determining unit

16

knee point

18

instance

20

mixer

A

output signal

E

input signal

Eger

directional input signal

emod

modified input signal

EP

input level

G

reinforcement

H

rear

K

compression scheme

L

Left

N

user

R

relevant direction

S

to the right

V

front

Claims (9)

1. Method for operating a hearing aid (2),

   - wherein the hearing aid (2) generates an input signal (E) from acoustic signals from the environment,

   - wherein the hearing aid (2) comprises a signal processor (4), which is configured to modify the input signal (E) and to thereby generate an output signal (A),

   - wherein in order to modify the input signal (E), the signal processor (4) comprises an automatic gain control (10) comprising a compressor (12) operable with a compression scheme (K),

   - wherein the environment is subdivided into a plurality of directions (V, H, L, S), one of which is selected as a relevant direction (R) by means of a direction determination unit (14),

   - wherein the input signal (E) is modified direction-dependently by operating the compressor (12) with a compression scheme (K) which is set depending on the relevant direction (R), so that acoustic signals from the relevant direction (R) are emphasized over acoustic signals from other directions, characterized in that

   the compressor (12) comprises a plurality of instances (18), which are operated with different instance schemes, wherein a respective instance scheme is configured for emphasizing a particular type of acoustic signal, wherein the input signal (E) is respectively fed to the plurality of instances (18), which then generate a corresponding number of modified input signals (Emod), which are then combined together to form the output signal (A), wherein a proportion ratio of the modified input signals (Emod) to each other in the output signal (A) is set depending on the relevant direction (R), so that the compression scheme (K) is set as a mixture of the instance schemes,
   or

   that the input signal (E) comprises a plurality of directional input signals (Eger) each assigned to one of the plurality of directions (V, H, L, S), wherein the compressor (12) comprises an instance (18) for each of the directional input signals (Eger) which is operated with a respective instance scheme, wherein a respective instance (18) is fed to one of the directional input signals (Eger), so that the compression scheme (K) is set as a mixture of the instance schemes, wherein each directional input signal (Eger) is modified separately and the modified input signals (Emod) are then mixed together in a mixer (20), wherein a proportion ratio of the modified input signals (Emod) to the output signal (A) is set in such a way that an optimum compression scheme (K) results overall.
2. Method according to the preceding claim,
   wherein the direction determination unit (14) comprises a beamformer, by means of which the environment is subdivided into a plurality of directions (V, H, L, S) and which is used to determine the relevant direction (R).
3. Method according to one of the preceding claims,

   wherein the compression scheme (K) is defined by at least one compression parameter, and

   wherein the compression scheme (K) is set depending on the relevant direction (R) by the compression parameter being modified depending on the relevant direction (R).
4. Method according to one of the preceding claims,
   wherein, if the input signal (E) comprises a plurality of directional input signals (Eger), for each of the directions (V, H, L, S), a respective instance scheme for the respective directional input signal (Eger) is set depending on a type of an acoustic signal in the assigned direction (V, H, L, S).
5. Method according to one of the preceding claims,
   wherein the compression scheme (K), in particular the instance scheme, which is set, is selected from a set of compression schemes (K) comprising: a speech scheme, for emphasizing speech components, a sound scheme, for adapting only to a listening profile of a user (N) of the hearing aid (2).
6. Method according to one of the preceding claims,
   wherein the input signal (E) is modified direction-dependently only if a directional acoustic signal is detected in the environment, and wherein otherwise the input signal (E) is modified direction-independently.
7. Method according to one of the preceding claims,
   wherein a plurality of directions (V, H, L, S) are each selected as a relevant direction (R).
8. Method according to one of the preceding claims,
   wherein the environment is subdivided into exactly four directions (V, H, L, S), namely front (V), rear (H), left (L) and right (S).
9. Hearing aid (2) configured to perform a method according to one of the preceding claims.

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