Hearing system and methods for generating monaural or binaural beats

Abstract

The hearing system (2) is in particular a binaural hearing system (2) designed to generate monaural or binaural beats and for this purpose comprises at least one hearing aid (4A, 4B) with a main signal path (8). The hearing aid (4A, 4B) further comprises a secondary signal path (26) with a signal generator (28) for generating a first beat signal (B1), wherein the first beat signal (B1) is frequency-shifted by one beat frequency relative to a further signal (B2), such that the effect of the monaural or binaural beat is generated for the user during operation. The signal generator (28) is configured such that the first beat signal (B1) has at least one signal component, referred to as an ambient signal (SU), at least in certain operating modes of the hearing aid (4A, 4B), which is generated on the basis of the electrical input signal (E1) and thus on the basis of the ambient noise.Preferably, the beat signal (B1, B2) is composed of different signal components, the weighting (G) of which is preferably set depending on a signal level of the input signal.

Description

The invention relates to a particularly binaural hearing system and a method for generating monaural or binaural beates with the aid of such a hearing system.In the present case, a hearing system is understood to mean a system with at least one hearing device and, in the case of a binaural hearing system, a system with two hearing devices. The hearing aids are electronic devices which a user wears on the ear, behind the ear or in the ear. The hearing system is in particular a hearing aid system which is configured to compensate for user-specific hearing damage of a person who is impaired by hearing.Such a hearing device usually has an input transducer, which first converts an acoustic or a streamed input signal into an electrical input signal, which is subsequently processed by means of an in particular digital signal processing unit to form an electrical output signal, which is fed to an output transducer, which converts the electrical output signal into an acoustic output signal, which is emitted to the ear of the listener.Monaural beates or binaural beates are understood to mean known effects of sensation perception in the human brain, in which the user perceives a pulsating sound (beate) when two identical acoustic signals are presented to him at slightly different frequencies. In binaural beates, the two acoustic signals which are frequency-shifted with respect to one another are presented to the user on two channels, namely on the left ear and on the right ear. In monaural beates, the two frequency shifted acoustic signals are presented on only one channel.With such monaural or binaural beates, certain training effects for the brain can be achieved.On the basis of this, the invention is based on the object of generating acoustic output signals with the aid of a hearing system, which are suitable for generating a pleasant perception of monaural or binaural beates by the user.The object is achieved according to the invention by a hearing system, in particular a binaural hearing system having the features of claim 1, and by a method for generating monaural or binaural beates with the aid of such a hearing system. Advantages and preferred embodiments stated with regard to the hearing system are to be transferred analogously also to the method and vice versa.The hearing system is in particular a hearing aid system which is set up in a user-specific manner and is designed to compensate for user-specific hearing damage.The hearing system has at least one hearing device and preferably, especially in the embodiment as a binaural hearing system, two hearing devices, whereinthe at least one hearing device has a main signal path, having an input transducer for generating an electrical input signal from an input signal, for example acoustic or streamed, having an in particular digital signal processing unit for processing the electrical input signal and for generating an electrical output signal, and having an output transducer which generates an acoustic output signal on the basis of the electrical output signal,the at least one hearing device further has a secondary signal path, each with a signal generator for generating a first beat signal, wherein the first beat signal is frequency-shifted by one beat frequency with respect to a further signal in such a way that the effect of the monaural or binaural beat is generated during operation by the user,the at least one hearing device has a summer which sums at least the first beat signal to a signal of the main signal path, so that the acoustic output signal is formed by a normal audio signal component and a beat signal component,the signal generator (28) is connected to the first signal path (8) and is configured such that the first beat signal (B1) has at least one signal component, referred to as an environmental signal, at least in certain operating modes of the hearing aid (4A, 4B), which signal component is generated on the basis of the electrical input signal (E1).In the case of a binaural hearing system, the two hearing devices each have a communication unit which forms a communication interface via which the two hearing devices mutually communicate and exchange data in a known manner. In particular, a Bluetooth connection is formed for this purpose.In a hearing system with two hearing aids, in particular in a binaural hearing system, the second hearing aid likewise has a main signal path with the components listed above.In a preferred embodiment, but not necessarily, such a second hearing device also has a secondary signal path in which a signal generator for generating a second beat signal is likewise arranged. In this embodiment variant, the two beat signals are frequency-shifted with respect to one another by the beat frequency. The second hearing device also has a summer in this case, which sums the second beat signal to a signal of the first signal path. As a result, an acoustic output signal is also generated in the second hearing device, which is formed by a normal audio signal component and a beat signal component on the basis of the second beat signal.The normal audio signal component is understood in the acoustic output signal to mean that signal component which would result without the summation of the beat signal.In the present case, beat frequency is understood to mean the frequency by which the two beat signals are frequency-shifted with respect to one another. The beat frequency is typically in the range from 0.5 Hz to 60 Hz, preferably at most to 55 Hz and frequently in the range between 3 Hz and 30 Hz.To generate the frequency-shifted beat signal, at least the one signal generator has a frequency shifter, which thus shifts a signal generated or provided by the signal generator (e.g. ambient signal sinusoidal signal, narrowband noise, signal component) by the beat frequency and thus generates the frequency-shifted beat signal.By using the environmental signal, i.e. the acoustic input signal detected by the input transducer, as a basis for the generation of the (frequency-shifted) first beat signal, the advantage is achieved that the generation of the beat signals and thus for the generation of the perception of the beat the environmental noises are used as a basis. This is perceived as particularly pleasant by the user, since no additional, extraneous signal components are contained in this case. At the same time, however, the desired perception of the monaural or binaural beates is still achieved.The signal profile of the ambient signal corresponds to the signal profile of at least one selected frequency band of the input signal.The configuration of a secondary signal path in the second hearing device is not absolutely necessary, even in binaural hearing devices and / or in the generation of binaural beates.In the case of the generation of monaural beates, for example, only within the at least one hearing device is a normal signal component provided on the basis of the input signal and a frequency-shifted signal component provided on the basis of the input signal as beate signals, which then lead to the perception of the monaural beates. In one embodiment variant, it is also sufficient when binaural beat is generated, for example, in the signal generator of the first hearing device, if the first beat signal is generated on the basis of the input signal merely by a frequency shift of the input signal or of signal components of the input signal and is provided as the environmental signal. The binaural effect is generated, for example, by the audio signal (acoustic output signal) at the second hearing device and by the frequency-shifted beat signal component (on the basis of the first beat signal) in the acoustic output signal of the first hearing device.In particular in such variants, a secondary signal path is dispensed with in the second hearing device and / or a frequency-shifted beat signal is generated only in the first hearing device.However, the variant is preferred in which both hearing devices have a signal secondary path and in each case a signal generator. In this case, therefore, in both hearing devices, the beat signals generated by the respective signal generator have at least the surrounding signal as the signal component. In one variant, the beat signals consist of the environmental signal. The beat signals and thus also the environmental signals of the two beat signals are identical in this case, except for the frequency shift by the beat frequency. In some variants, the two beat signals / environment signals can also differ with regard to their amplitude.If a beat signal is mentioned in the present case, this is generally understood to mean a signal which contributes in the acoustic output signal to a signal component which contributes to the generation of the desired effect of the monaural or binaural beat. At least in some specific operating modes of the hearing device, these signal components (environmental signal) are based on the environmental noise, that is to say on the acoustic input signals.According to a preferred embodiment, the at least one hearing device has an analysis unit for analyzing the input signal and the beat signal is composed of one or more signal components. The signal generator is configured to carry out the composition of the beat signal on the basis of the analysis of the input signal.The various signal components from which the beat signal is composed as a function of the analysis of the input signal and thus of the ambient noise are preferably selected from the ambient signal, a sinusoidal signal and an in particular narrowband noise signal. Each of these signals therefore forms a possible signal component of the respective beat signal.Narrowband noise signal is understood to mean a noise which extends over a frequency band which preferably only has a bandwidth of 100 Hz to 300 Hz. The noise signal is preferably between 250 Hz and 5 kHz.These further signals besides the ambient signal can also be generally referred to as carrier signals which are independent of the input signal.Preferably, the respective signal generator has an individual generator part configured for the signal component for each signal component.The selection of the signal components and the composition of the beat signal preferably takes place as a function of a signal level of the (acoustic) input signal. The respective beat signal can in this case consist of in each case only one signal component, of a plurality of signal components or else of all signal components.This embodiment is based on the realization that different types of beat signals are particularly pleasant for the user for different signal levels of the input signal.It has thus been found that for low signal levels, an individual sound is perceived as a beat signal based on a sinusoidal signal as being more disturbing or unpleasant than a particularly narrow-band noise. As the signal level increases, this situation reverses and the sine signal is perceived as more pleasing. Finally, at higher signal levels, the use of ambient signals is perceived as particularly pleasant, since otherwise very loud sinusoidal signals would have to be generated, for example, as additional signals, which are then perceived as disturbing.The signal level of the input signal is generally a characteristic value for the signal level, that is to say for the amplitude of the acoustic or else of the streamed input signal, which is detected by the input transducer. The (instantaneous) signal level is determined here regularly on the basis of an evaluation of the converted electrical input signal. Specifically, the determination of the signal level is an estimation. Therefore, the determination of the signal level overall determines or estimates a signal level and thus an amplitude of the instantaneous ambient noise.Different methods can be used to determine the signal level. For example, a broadband signal component of the input signal, for example the complete bandwidth of the audible frequency spectrum or only a subband, is evaluated. Here, for example, the signal levels in different frequency bands are averaged, and the averaged signal level is regarded as the signal level of the input signal. Alternatively, the frequency band with the highest signal level is used and this maximum signal level is considered as the signal level of the input signal.It is also possible to define a reference frequency at which the signal level is determined as a reference level and thus as a signal level of the input signal. The reference frequency is, for example, a mean frequency of a selected frequency band or the frequency with the highest signal level. The frequency band and / or the reference frequency are, for example, permanently predefined or alternatively dynamically determined in each case on the basis of the instantaneous maximum signal level.In an expedient development, it is furthermore provided that a different weighting of the signal components is carried out as a function of the determined signal level. This means that the weighted composition of the respective beat signal changes with the signal level.Weighting is preferably understood to mean the signal level of the respective signal component in the acoustic output signal. If the respective signal component extends over a frequency band, such as for example in the case of the noise or the ambient signal, the weighting is determined by the maximum signal level within the frequency band or alternatively by a mean signal level within the frequency band.The weighting and thus the signal level of the various signal components is adjusted in particular with the aid of at least one adjustable amplifier element.The amplifier element preferably has an amplifier sub-component for each of the signal components in order to be able to set the individual weighting factors and thus amplification factors independently of one another. Expediently, each individual generator part which is configured for a respective signal component is assigned a respective amplifier sub-component.On the basis of the above-described knowledge in connection with the effect of the various signal components as a function of the signal level of the input signal in particular, it is provided in particular that the weighting of the environmental signal increases with increasing signal level.Alternatively or additionally, in the case of a low signal level, the weighting of the environmental signal is lower than that of the further signal components, specifically in particular as each individual one of the other signal components. As the signal level increases, the weighting of the surrounding signal increases and finally exceeds the other signal components in each case, for example in a medium level range.In a preferred embodiment, the noise signal is weighted the highest at a lower, low level range of the signal level of the input signal, the sine signal is weighted the highest at a middle level range and the ambient signal is weighted the highest at a high level range. Overall, therefore, a qualitative weighting profile results, in which the particularly narrow-band noise predominates in the case of a low signal level, the sinusoidal signal subsequently predominates in the case of a medium level range, and the surrounding signal finally predominates in the case of a high level range. A low signal level is understood in particular to mean a signal level up to 50 dBSPL or also up to 55 dBSPL (decibels sound pressure level - dB sound pressure level). An average signal level is understood to mean a level range between 50 / 55 dBSPL-75 dBSPL or even up to 80 dBSPL, and a loud signal level is understood to mean in particular a level above 75 dBSPL or even 80 dBSPLIn a preferred embodiment, the analysis is carried out recurrently and in particular continuously and continuously. A time interval between two successive analysis steps is preferably less than 300 ms and is, for example, 100 ms. The time interval is generally preferably between 100 ms to 300 ms. On the basis of each of these analyses carried out continuously and repeatedly, the composition of the beat signal is then adapted as a function of the instantaneous analysis, i.e. the composition of the beat signal and thus the weighting of the various signal components changes over time. The composition is therefore virtually continuously tracked to the level profile of the input level.In addition to the analysis and determination of the signal level of the input signal, further parameters are preferably used, on the basis of which the composition of the beat signal is determined. Such parameters are, for example, instantaneous state values of the respective user, for example the heart beat, movements or accelerations of body parts, etc. These parameters are optionally derived using an additional device or else indirectly from the input signals. This embodiment is based on the consideration that, even in certain state situations of the user, for example, during sleep, sports, etc., different signal components are well suited for the desired effect.In an expedient embodiment, the ambient signal is a band-filtered ambient signal. The hearing device accordingly also has a suitable bandpass filter, so that the ambient signal is filtered out of the detected input signal via the latter and has a predefined bandwidth. This is based on the consideration that only a specific frequency range is particularly suitable for generating the perception of the beates.Preferably, the band-filtered ambient signal has a bandwidth in the range from 100 Hz to 400 Hz. Furthermore, the ambient signal is preferably in a medium band range between 200 Hz and 1000 Hz, and in this case has in particular the aforementioned bandwidth.According to a preferred development, parameters of the band-filtered ambient signal, such as bandwidth, medium frequency or lower or upper band frequency, are set as a function of a user-specific audiogram, that is to say as a function of a user-specific hearing damage. Specifically, the bandwidth and / or the average frequency is chosen to be outside a frequency band where the user has large hearing deficits compared to other frequency bands where high gain is required.The frequency band of the ambient signal is therefore placed in particular in such a frequency range where a comparatively low user-specific amplification is required.In an expedient embodiment, the hearing system is configured such that the values of the parameters of the band-filtered ambient signal, such as bandwidth, medium frequency or lower or upper band frequency, vary over time and in particular depending on the instantaneous input signal. The parameter values are selected, for example, depending on the signal level. Specifically, for example, an average frequency of the ambient signal is selected such that it lies outside a frequency or a frequency band with the highest signal level of the input signal. This serves to avoid masking effects.Overall, therefore, the band-filtered ambient signal is an ambient signal which is dynamic over time and the parameter values of which vary, in particular as a function of the input signal, specifically as a function of the signal level of the input signal.In a preferred development, an adjusting device is preferably assigned to the respective signal generator in each hearing device, wherein the adjusting device has the previously described, adjustable amplifier element. The aforementioned analysis unit is also part of this adjustment device. Furthermore, the setting device is configured to set a signal level of at least the first beat signal and preferably of both beat signals as a function of a current signal level of the input signal.By this measure, the signal level of the beat signal is adjusted in particular continuously to the instantaneous signal level of the input signal. The carrying out of the analysis and the corresponding setting of the signal level of the beat signals are preferably carried out in time periods of less than 500 ms and, for example, every 100 ms.The tracking of the signal level of the beat signal leads to a particularly pleasant perception of the monaural or binaural beat.In a preferred embodiment, the hearing system has a user-specific setting element, by means of which a manual setting of the beat signal, in particular of the signal level of the beat signal, is possible. For this purpose, the hearing system has, for example, an operating interface, in particular in the form of a portable device such as, for example, a smartphone, on which an application is installed, via which settings for the respective hearing device can be carried out. This portable device is part of the hearing system. Alternatively or additionally, control elements can also be arranged directly on at least one hearing device, via which the adjustment can take place.These manual adjustment options therefore offer the user the possibility of adjusting parameters which influence the beates themselves at least in order to obtain the most comfortable possible receiver feeling. The parameters are in particular the beat frequency and / or the amplification factor for the amplifier element or the signal level of the respective beat signal, in particular the level interval compared to the normal audio signal component in the acoustic output signal.In a preferred development, the hearing system has a status detector, i.e. is designed for automatic detection of a current status of the user. Furthermore, the hearing system, in particular the setting device, is configured to set the at least one beat signal as a function of the identified current status. The user's status is understood to mean, in particular, a current physical state of the user, which is determined, for example, by determining the current pulse of the user and / or by acceleration sensors. The determination of the current status can be carried out either with auxiliary devices or directly also with the aid of the hearing device. For example, acceleration sensors can be integrated in the hearing device or the hearing device is designed to determine the instantaneous pulse of the hearing device wearer from acoustic signals, e.g. structure-borne sound signals.In particular, a sleep mode is identified, in particular compared to a wake-up mode, wherein the parameters are then set differently for the different modes. Parameters for the beat signal are in turn understood to mean in particular the beat frequency (i.e. the magnitude of the frequency shift between the beat signals) and / or the signal level. For example, in an identified sleep mode, the signal level is reduced compared to a wake-up mode. Additionally or alternatively, different beat frequencies are set for the awake mode and the sleep mode. It is known that different beat frequencies have different effects and training effects for the brain.In a preferred embodiment, for example in the sleep mode, the beat frequency is set to a range between 35 Hz and 45 Hz and in particular to 40 Hz. Studies have shown that such beat frequencies have particular advantages, especially in sleep mode.Exemplary embodiments of the invention are explained in more detail below with reference to the figures, in which FIG. 1 is a simplified block diagram of an embodiment of a binaural hearing system for explaining the tracking of a signal level of beat signals as a function of the signal level of an input signal, FIG. 2 shows a detail illustration based on the hearing system according to FIG. 1 for explaining the composition of the beat signals from different signal components, and FIG. 3 shows a representation of a qualitative course of the weighting of the various signal components as a function of the signal level of the input signal.A hearing system 2 illustrated in FIG. 1 is designed as a hearing aid system which is set up to compensate for user-specific hearing damage. This is a binaural hearing system 2 with two hearing devices 4A, 4B, which each communicate with one another in a manner known per se via a wireless communication unit, in particular a Bluetooth communication interface, which is not shown in detail here. The two hearing devices 4A, 4B are at least largely identical in construction. Differences will be discussed explicitly.A respective hearing device 4A, 4B has in each case one or more input transducers 6, in particular microphones, by means of which an input signal, in particular an acoustic environmental signal, is converted into an electrical input signal E 1, E 2. This is first processed in a main signal path 8 and in a signal processing unit 10 in a manner known per se specifically on the basis of a user-specific audiogram and thus corresponding to a user-specific hearing damage. The processed electrical signal is supplied as an electrical output signal A1, A2 to an output converter 12 which converts the electrical output signal into an acoustic output signal aA1, aA2. The output transducer 12 is in particular a loudspeaker.The signal processing unit 10 has, for example, on the input side a filter bank 14, via which the electrical input signal E 1, E 2 is divided into different frequency bands for the subsequent signal processing. Subsequently, a plurality of signal processing units 16, 18 are usually provided, such as a beam former for generating directionality or also a noise suppressor for reducing disturbing ambient noises. An electrical input signal E1, E2 partially processed by the signal processing units 16, 18 is then fed to a summer 20. Arranged downstream of the summer 20 is a signal amplifier 22, typically with an integrated compression unit. Finally, a synthesizing filter bank 24, for example, is arranged downstream of the signal amplifier 22, which filter bank merges the individual frequency bands again and at the end of which the electrical output signal A 1, A 2 is output.In addition to the main signal path 8, a respective hearing device 4A, 4B has a secondary signal path 26. This has a signal generator 28 for generating a beat signal B 1, B 2. A further signal is provided via the signal generator 28, in particular in addition to the electrical input signal E 1, E 2. This is in particular a signal independent of the input signal, especially a sinusoidal signal or an in particular narrowband noise signal. In addition, it is also possible to use as the basis for the beat signal B 1, B 2 a signal component of the electrical input signal E 1, E 2 picked up by the input converter 6, i.e. ambient noise. The beat signal B 1, B 2 is composed, for example, of a plurality of signal components which are formed on the basis of or by the aforementioned signals (sinusoidal signal, noise signal, ambient noise).At least in one of the two signal generators 28, in the embodiment in the first hearing device 4A, a frequency shifter 30 is integrated, with the aid of which the previously generated signal (e.g. sinusoidal signal, noise signal) is shifted by a beat frequency. The two beat signals B 1, B 2 are therefore two identical signals with the same signal components, which are shifted with respect to one another only by the beat frequency.Furthermore, a respective hearing device 4A, 4B has in each case an analysis unit 32, which is configured to determine, in particular estimate, a current signal level L m of the (acoustic) input signal. For this purpose, the analysis unit 32 suitably evaluates the electrical input signal E 1, E 2, which is present upstream of the adder 20 and is optionally partially processed.Depending on the current signal level L m determined in this case, which is currently present, a current amplification factor is determined, with which the respective beat signal B 1, B 2 is amplified. For amplification, an amplifier element 34 is arranged in each case. The analysis unit 32 and the amplifier element 34 are components of an adjustment device 36, by means of which a respective signal level L B for the beat signal B 1, B 2 is adjusted.According to a preferred embodiment, as shown in the figure, a synchronizer 38 is arranged at least in one of the hearing devices 4A, 4B, which synchronizer is connected to the two analysis units 32 and receives information from these about the respective signal level L m. This information is transmitted from the one hearing device 4B to the synchronizer 38 arranged in the other hearing device 4A, in particular via the previously described communication interface of the binaural hearing system 2.The synchronizer 38 evaluates the two instantaneous signal levels L m and compares them in particular and determines suitable synchronized amplification factors for the two beat signals B 1, B 2 on the basis of this evaluation. In the case of greatly different instantaneous signal levels L m the synchronizer 38 ensures, in particular, a limitation of the differences of the signal levels L B of the beat signals B 1, B 2.In an alternative, simplified embodiment variant not shown in detail here, each adjusting device 36 of the two hearing devices 4A, 4B individually determines a respective instantaneous amplification factor for the respective beat signal B 1, B 2. In this variant, therefore, the synchronizer 38 and a synchronization are dispensed with.The respectively amplified beat signal B1, B2 is then fed to the adder 20. Subsequently, the resulting composite signal, which has as signal components the partially processed input signal E 1, E 2 and the beat signal B 1, B 2, is fed to the signal amplifier 22, amplified there and finally provided after the synthesizing filter bank 24 as the outgoing electrical output signal A 1, A 2, which is subsequently converted by the output converter 12 into the acoustic output signal aA 1, aA 2.The respective acoustic output signal aA1, aA2 is therefore composed of a normal audio signal component and a beat signal component. The normal audio signal component is the signal component which would result without the respective signal component of the beat signals. The beat signal components in the acoustic output signal aA1, aA2 are frequency-shifted with respect to one another by the beat frequency and optionally have different amplitudes, but are in fact identical.Therefore, in addition to the normal audio signal, two (acoustic) beat signals B 1, B 2 offset with respect to one another by the beat frequency are provided to the user on both ears, so that the binaural beat is perceived by the user as desired.The instantaneous signal level L m is preferably detected continuously and preferably at time intervals of less than 300 ms and, for example, every 100 ms, and the signal level L B of the beat signals B 1, B 2 is continuously tracked on the basis of the detected instantaneous signal levels L m. This is preferably such that a higher signal level L B of the beat signal components is established in the acoustic output signal aA 1, aA 2 compared to the signal levels L m of the normal audio signal component. Preferably, the signal level L B of the beat signal components is higher by 1 dB to 5 dB and in particular by 3 dB.In the present case, the electrical input signals are uniformly provided with the reference symbols E 1, E 2 over the entire main signal path 8, independently of their processing status.In the present case, the further (beat) signals provided by the respective signal generator 28 are denoted uniformly by the respective reference symbols B 1, B 2 over the entire signal path and thus in different processing stages.FIG. 2 shows a detail, enlarged illustration of the hearing system 2 in the region of the secondary signal path 26.In the embodiment according to FIG. 2, beat signals B 1, B 2 are composed of different signal components. A weighting G of the various signal components is effected in this case as a function of the signal level L m of the acoustic input signal.For this purpose, the signal generator 28 is initially divided into a plurality of generator parts 28A, 28B and 28C. In addition, the amplifier element 34 is also divided into a plurality of individually adjustable amplifier subcomponents 34A, 34B and 34C. The various generator parts 28A to 28C are configured to generate different signals as the signal components. This is in particular an ambient signal Su, a sinusoidal signal Ss and a narrowband noise signal S N.The generating part 28A is used to generate the ambient signal Su. For this purpose, the input signal E1, E2 is applied to the input side. It has, for example, an integrated bandpass filter 40, so that a narrowband signal part is cut out of the input signal E 1, E 2, which then forms the ambient signal Su.The generator parts 28A- 28C of the two hearing devices 4A, 4B are identical to one another, with the difference that a frequency shifter 30, which is not explicitly shown here, is additionally integrated in the generator parts 28A to 28C of the first hearing device 4A in order to generate the desired frequency shift by the beat frequency.The generator parts 28B, 28C each generate independent signals independently of the electrical input signal E 1, E 2.Via the respective amplifier sub-component 34A to 34C, which are assigned to a respective generator part 28A to 28C, the different signal components S U, S N, S S. are individually amplified. These are subsequently combined in a combiner 42, which is designed in particular as a summer, and then form the respective beat signal B 1, B 2, which is fed to the summer 20 in the main signal path 8.The individual amplification factors for the different signal components S U, S N, S S are adjusted as a function of the signal level L M of the input signal. For this purpose, as already described with reference to FIG. 1, an analysis unit 32 is integrated in each hearing device 4A, 4B, which analysis unit is designed for determining and in particular estimating the incoming signal level L M.In FIG. 2, an embodiment variant with the synchronizer 38 is shown analogously to FIG. 1. This in turn serves for synchronized actuation of the amplifier element 34. In contrast to FIG. 1, however, the amplifier subcomponents 34A to 34C are now each individually controlled, so that different amplification factors and thus weights G are set for the different signal components Su, S N, Ss. This means that the different signal components S U, S N, S S in the beat signal B 1, B 2 which is then composed are weighted differently. The signals B 1, B 2 then each have a signal level L B. The amplification factors for the signal components S U, S N, S S are selected in a suitable manner in such a way that the desired value for the signal level L B is achieved, as has been described in particular in connection with FIG. 1.In an alternative embodiment, the synchronizer 38 is omitted and the weights G are adjusted in the two hearing devices, for example independently of one another and on the basis of the signal level L m. determined by the analysis unit 32 of the respective hearing device 4A, 4B.FIG. 3 shows the qualitative course of the weighting of the different signal components S U, S N, S S as a function of the signal level of the input signal L m. The signal level L M is indicated on the x-axis (increases from left to right) and the weighting G and thus the amplification of the various signal components S U, S N, S S is shown on the y-axis.As can be seen from this, at a low, low signal level L m the noise signal S N, whose weighting G decreases with increasing signal level L m predominates, namely preferably in the manner of a hyperbolic curve which approximates asymptotically to a minimum value which is preferably 0 or alternatively unequal to 0.At the low, low signal level L m the sinusoidal signal Ss also has a weighting factor which is high-in comparison with the ambient signal Su-but which is lower than that of the noise signal S N. The weighting factor of the sinusoidal signal SS decreases with increasing signal level L m and preferably linearly.In general, the noise signal S N falls more strongly with increasing signal level L m than the sinusoidal signal Ss, so that their two curves intersect, so that the sinusoidal signal Ss predominates in a medium level range.In contrast to these two signal components S N, S S the ambient signal Su increases with increasing signal level L m. The increase takes place exponentially, for example.In the low, low level range, the ambient signal Su starts at a constant value, in particular at 0, so that in the low level range the beat signal B 1, B 2 is composed exclusively of the two other signal components S S, S N.In the middle level range, on the other hand, the respective beat signal B 1, B 2 is composed of all three signal components S U, S N S S wherein the weighting varies within the middle level range. The intersection point of the weighting curves of the signal components S S, S N is considered to be the beginning of the mean level range in the present case.In the middle level range, the weighting of the ambient signal Su increases increasingly, wherein it initially exceeds, for example, the weighting of the noise signal S N and later also the weighting of the sinusoidal signal S S. The signal level L m, from which the greatest weighting component is formed by the ambient signal S U is defined in the present case as the end of the mean level range. In the present case, it is the intersection point between the weighting curve of the sinusoidal signal Ss and the environmental signal Su.In the high level range following the middle level range, the weighting G of the environmental signal Su increases more and more, while the weighting of the two other signals S N, Ss decreases more and in particular also decreases down to 0. In high level ranges, therefore, the surrounding signal Su is present predominantly (greater than 75% of the total level) or else exclusively, so that the respective beat signal B 1, B 2 is therefore formed predominantly or exclusively by the surrounding signal Su.The different weighting of the different signal components Su, S N, S S as a function of the signal level L m is based here on the finding that the different signal components Su, S N, Ss are perceived differently as a function of the signal level L m. Thus, investigations have shown that a pure sinusoidal tone is perceived as unpleasant at low signal levels, whereas in a medium level range it is perceived as more pleasant in comparison to a noise signal. In the case of high level ranges, the use of the ambient signal Su as a signal component has proven to be particularly advantageous.The units mentioned above, such as filter bank 14, 24, signal processing unit 16, 18, summer 20, signal amplifier 22, signal generator 28 having generator parts 28A-28C, frequency shifter 30, analysis unit 32, amplifier element 34 having amplifier subcomponents 34A-34C, synchronizer 38 and bandpass filter 40, are each electronic components or groups of electronic circuit components which, during operation, implement the desired functions described. These units are integrated, for example, in one or more integrated circuits, microchips and / or asics.List of reference characters2 Hearing system 4A, B Hearing device 6 Input transducer 8 Main signal path 10 Signal processing unit 12 Output transducer 14 Filter bank 16 Signal processing unit 18 Signal processing unit 20 Summer 22 Signal amplifier 24 Synthesizing filter bank 26 Secondary signal path 28 Signal generator 28A-C Generator parts 30 Frequency shifter 32 Analysis unit 34 Amplifier element 34A-C Amplifier sub-component 36 Setting device 38 Synchronizer 40 Bandpass filter E 1, E 2 Electrical input signal A 1, A 2 Electrical output signal aA 1, aA 2 Acoustic output signal B 1, B2 beat signal L m signal level of the input signal L B signal level of the beat signal S U ambient signals S S sinusoidal signal S N noise signal G weighting

Claims

Hearing system (2), in particular binaural hearing system (2), which is designed for generating monaural or binaural beates, having at least one hearing device (4A, 4B), wherein - the at least one hearing device (4A, 4B) has a main signal path (8), having an input converter (6) for generating an electrical input signal (E1, E2) from an in particular acoustic input signal, having a signal processing unit (10) for processing the electrical input signal (E1, E2) and for generating an electrical output signal (A1, A2), and having an output converter (12) which generates an acoustic output signal (aA1, aA2) on the basis of the electrical output signal (A1, A2), - the at least one hearing device (4A, 4b) furthermore has an auxiliary signal path (26), having a signal generator (28) for generating a first beat signal (B1), wherein the first beat signal (B1) is frequency-shifted by one beat frequency to a further signal (B2), in such a way that the effect of the monaural or binaural beat is generated during operation at the user, - the at least one hearing device (4A, 4B) has a summer (20) which sums at least the first beat signal (B1) onto a signal of the main signal path (8), wherein - the signal generator (28) is connected to the first signal path (8) and is configured in such a way that the first beat signal (B1) is summed at least in specific operating modes of the hearing device (4A, 4b) has at least one signal component, referred to as an environmental signal (S U) which is generated on the basis of the electrical input signal (E1).Hearing system (2) according to the preceding claim, which is designed as a binaural hearing system (2) and for generating binaural beates, having the at least one, first hearing device (4A) and having a second hearing device (4B) which are designed for wireless binaural communication with one another, wherein - each of the hearing devices (4A, 4B) has a main signal path (8), having an input converter (6) for generating an electrical input signal (E1, E2), having a signal processing unit (10) for processing the input signal (E1, E2) and for generating an electrical output signal (A1, A2), and having an output converter (12) which generates an acoustic output signal (aA1, aA2) on the basis of the electrical output signal (A1, A2), each of the hearing devices (4A, 4B) furthermore has a secondary signal path (26), each having a signal generator (28) for generating the first beat signal (B1) in the first hearing device (4A) and a second beat signal (B2) in the second hearing device (4B), wherein the two beat signals (B1, B2) are frequency-shifted with respect to one another by a beat frequency in such a way that the effect of the binaural beat is generated during operation by the user, - each of the hearing devices (4A, 4B) has a summer (20) which sums the beat signals (B1, B2) onto a signal of the main signal path (8), wherein - each of the signal generators (38) is connected in each case to the first signal path (8) and is configured in such a way, the beat signal (B1, B2) having at least one signal component, referred to as an environmental signal (S U) and generated on the basis of the electrical input signal (E1, E2), at least in certain operating modes of the hearing device (4A, 4B).Hearing system (2) according to one of the preceding claims, in which the at least one hearing device (4A, 4B) has an analysis unit for analyzing the input signal and the beat signal (B1, B2) is composed of one or more signal components (S U, S N, S S) wherein the signal generator (38) is configured to perform the composition of the beat signal (B1, B2) on the basis of the analysis of the input signal.Hearing system (2) according to the preceding claim, in which the signal components (S U, S N, S S) are selected from a sinusoidal signal (S S), an in particular narrowband noise signal (S N) and the ambient signal (S U). derived from the electrical input signal.Hearing system (2) according to one of the two preceding claims, in which the analysis unit (32) is configured to analyze a signal level (L m) of the input signal and which is used to combine the beat signal (B1, B2) on the basis of the analysis of the input signalHearing system (2) according to the preceding claim, in which a different weighting (G) of the signal components (S U, S N, S S) is carried out as a function of the signal level (L m).Hearing system (2) according to the preceding claim, in which the weighting (G) of the environmental signal (S U) increases with increasing signal level (L m).Hearing system (2) according to the preceding claim, in which, at low signal levels (L m) the weighting (G) of the environmental signal (S U) is lower than the weighting (G) of each of the other signal components (S N, S S).Hearing system (2) according to one of the two preceding claims, in which in a low level range of the signal level (L m) the noise signal (S N), in a medium level range the sine signal (S S) and in a high level range the surrounding signal (S U) is weighted the most.Hearing system (2) according to one of Claims 5 to 9, in which the analysis is carried out recurrently and the signal generator (28) is configured to adapt the composition of the beat signal (B1, B2) as a function of the instantaneous analysis.Hearing system (2) according to one of Claims 5 to 10, in which, in addition to the signal level (L m) further parameters are used as evaluation criteria for the composition of the beat signal (B1, B2) and the weighting (G) of the signal components (S U, S N, S S).Hearing system (2) according to one of the preceding claims, in which the at least one hearing device (4A, 4B) has a bandpass filter (40) for generating a bandpassed ambient signal (S U).Hearing system (2) according to the preceding claim, in which the environmental signal (S U) has a bandwidth in the range from 100 Hz to 400 Hz.Hearing system (2) according to one of the two preceding claims, in which the ambient signal (S U) is in a medium band range between 200 Hz and 1000 Hz.Hearing system (2) according to one of Claims 12 to 14, in which parameters of the band-filtered ambient signal (S U), such as bandwidth, medium frequency or lower or upper band frequency, are set as a function of a user-specific audiogram.Hearing system (2) according to one of Claims 12 to 15, in which parameters of the band-filtered ambient signal (S U), such as bandwidth, medium frequency or lower or upper band frequency, vary over time and in particular as a function of the instantaneous input signal.Hearing system (2) according to one of the two preceding claims, in which the signal generator (28) is assigned an adjusting device (36) which has an adjustable amplifier element (34), wherein the adjusting device (36) has an analysis unit (32) for determining a current signal level (L m) of the input signal, wherein the respective adjusting device (36) is configured to adjust a signal level (L B) of the first beat signal (B1) as a function of a current signal level (L m) of the input signal (E1, E2).Hearing system (2) according to one of the preceding claims, characterized in that it is designed for manual setting of the at least one beat signal (B1, B1) by the userHearing system (2) according to one of the preceding claims, characterized in that it is designed for automatic identification of a current status of the user, in particular a sleep state of the user, and in that it is designed for setting the at least one beat signal (B1, B2) as a function of the identified current status.Method for generating monaural or binaural beates in a hearing system (2) having at least one hearing device (4A, 4B), wherein - the at least one hearing device (4A, 4B) has a main signal path (8), having an input transducer (6) which generates an electrical input signal (E1, E2) from an in particular acoustic input signal, having a signal processing unit (10) which processes the electrical input signal (E1, E2) and generates an electrical output signal (A1, A2), and having an output transducer (12) which generates an acoustic output signal (aA1, aA2) on the basis of the electrical output signal (A1, A2), - the at least one hearing device (4A, 4B) furthermore has a secondary signal path (26), each having a signal generator (28), which generates a first beat signal, wherein the first beat signal is frequency-shifted by one beat frequency to a further signal in such a way that during operation the effect of the monaural or binaural beat is generated at the user, - the at least one hearing device (4A, 4B) has a summer (20) which sums at least the first beat signal onto a signal of the first signal path, wherein - the beat signal (B1, B2) has at least one signal component, referred to as an environmental signal, at least in specific operating modes of the hearing device (4A, 4B), which signal component is generated on the basis of the electrical input signal (E1, E2).

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