EP2104377A2 - Hearing system with subband signal interchange and corresponding method - Google Patents

Abstract

The system has a left hearing aid (10) with a communication device to transmit a signal to a communication device of a right hearing aid (20), where the signal corresponds to a real spectral part of entire frequency spectrum of an input signal. The transmitted signal together with a signal of a binaural processing unit (25) is binaurally processed in a spectral part of the spectrum by the processing unit, while the signal of the unit (25) is monaurally processed at a remaining part of the frequency spectrum by the aid (20). The devices comprise transmitters (16, 26) and receivers (17, 27). An independent claim is also included for a method for processing signals for a binaural treatment of a user.

Description

The present invention relates to a hearing system for the binaural supply of a user with a first hearing device and a second hearing device. The first hearing device has a first signal input device for supplying a first input signal and a first communication device. The second hearing device has a second signal input device for supplying a second input signal, a second communication device for receiving a signal from the first communication device and a second signal processing device for processing signals of the second signal input device and the second communication device to a common output signal. Moreover, the present invention relates to a method for processing signals for a binaural supply with a first and a second hearing device. The term "hearing device" is understood here to mean any sound-emitting device which can be worn in or on the ear, in particular a hearing device, a headset, headphones and the like.

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

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

A hearing aid system for the binaural care of a hearing impaired person comprises two hearing aids, one of which is worn on the left and the other on the right ear. When the two hearing aids communicate with each other in some way (eg, via a wireless connection), this is called a "binaurally-coupled hearing system." Such a binaurally coupled hearing system offers possibilities of spatial signal processing, which are not possible with a monaural system, since in this system signals can be transmitted from one side to the other.

For example, approaches to binaural beamforming algorithms (beamforming) or blind-source separation algorithms (blind-source separation) are known from the literature.

Common to these known algorithms is that the necessary transmission capacity of the connection between the devices must be comparatively high, since the entire input signal of the same side as well as the other side is required for calculating the output signal on one side. So it is a correspondingly high data transmission rate for broadband communication necessary, which is disadvantageous in terms of the associated high energy consumption, especially in hearing aids. As alternatives, only monaural methods are known, but come because of very small microphone distances, especially at low frequencies to their limits. Affected are, for example, methods for implementing a directional microphone, a blind-source separation, a feedback reduction, etc.

Such monaural methods with one, two or more microphones per side show very good performance characteristics at higher frequencies (> 2 kHz), such as noise suppression and noise performance. At low frequencies, however, they reach their limits as a result of the principle inherent noise problems (because of the inherent inherent noise of the microphones in combination with the small microphone spacing).

From the publication WO 99/431185 A1 is a binaural digital hearing aid system known in which data is transmitted crosswise from the right to the left and from the left to the right hearing aid. The data received from the other hearing aid is processed binaurally with the hearing aid's own data. If necessary, the data is compressed before transmission.

Furthermore, the document discloses EP 1 771 038 A2 a method for operating a hearing aid device system for binaural care of a user. In frequency ranges where problematic feedbacks are expected, the input signals are transmitted crosswise to the other hearing aid, respectively, so that one from the microphone of a hearing aid Recorded sound signal after the signal processing and amplification can be output via the handset of the other hearing aid. As a result, the distance between a respective handset and a microphone, between which a feedback path exists, is substantially increased for the relevant audio signals.

Furthermore, the document describes WO 2004/114722 A1 a binaural hearing aid system with coordinated sound processing. This data is exchanged with respect to the classification of the sound environment between the two hearing aids.

The object of the present invention is thus to provide a hearing system for the binaural supply of a user, in which data can be transmitted between two hearing devices, but in which the energy or computational effort for the data exchange or the processing of the exchanged data is minimized , In addition, a corresponding method for processing signals should be provided.

According to the invention, this object is achieved by a hearing system for binaurally supplying a user with a first hearing device including a first signal input device for supplying a first input signal and a first communication device, and a second hearing device including a second signal input device for providing a second input signal, a second communication device for receiving a signal from the first communication device and a second signal processing device for processing signals of the second signal input device and the second communication device into a common output signal, wherein the signal transmitted from the first to the second communication device corresponds to a true spectral part of the total frequency spectrum of the first input signal, and wherein in the spectral part of the total frequency spectrum, the transmitted signal together with ei a signal of the second signal processing device is binaurally processed by the second signal processing means, while the signal of the second signal processing means in the remaining part of the total frequency spectrum is processed by the second signal processing means monaural.

In addition, the invention provides a method for processing signals for a binaural supply with a first and a second hearing device by providing a first input signal in the first hearing device, providing a second input signal in the second hearing device, transmitting a signal from the first to the second Hearing device, processing the second input signal together with the signal from the first hearing device in the second hearing device to an output signal of the second hearing device, wherein the signal transmitted from the first to the second hearing device corresponds to a true spectral part of the total frequency spectrum of the first input signal, and wherein the transmitted signal is binaurally processed by the second hearing device together with a corresponding spectral part of the second input signal of the second hearing device to the spectral part of the total frequency spectrum while the second input signal of the second hearing device is processed monaurally in the remaining part of the total frequency spectrum by the second hearing device.

In an advantageous manner, it is thus avoided that signals in the full bandwidth are exchanged between the two hearing devices of a hearing system. Rather, only subbands of the relevant signals are transmitted. As a result, the flow of information and the associated computational effort can be reduced to a minimum.

Preferably, the first hearing device has a first signal processing device to receive signals from the first signal input device together with signals from the first communication device, that from the second hearing device come to process to a common output signal. This ensures a mutual exchange of data between the two hearing devices. Especially with this intensive data exchange can be benefited by the reduction of the transmission bandwidth.

The first and second signal input means may each comprise at least two microphones. Thus, for example, a beamforming or a high-quality directional microphone or a high-quality binding-source separation can already be realized in the individual hearing devices. In order to exploit the results for spatial hearing, only the relevant spectral components of these results are transmitted to the other hearing device.

In particular, it is favorable if only a low-frequency component of the respective input signal is transmitted during the signal transmission between the two communication devices. In this case, it is advantageous, for example, if the frequencies of the low-frequency component are less than 1 kHz or 2 kHz. As a rule, it is sufficient to exchange the low-frequency components for improving the binaural supply between the hearing devices or hearing aids.

As already indicated, in the first and / or second signal processing device, a feedback reduction algorithm, a beamforming algorithm or a blind-source separation algorithm can be implemented which uses signals from the respective other hearing device , This can be achieved especially in these algorithms, in which the data exchange between the hearing brings special advantages, a significant savings in computational effort and energy consumption.

FIG 1

den prinzipiellen Aufbau eines Hörgeräts gemäß dem Stand der Technik, und

FIG 2

ein Blockschaltbild eines erfindungsgemäßen Hörgerätesystems zur binauralen Versorgung.

The present invention will be explained in more detail with reference to the accompanying drawings, in which:

FIG. 1

the basic structure of a hearing aid according to the prior art, and

FIG. 2

a block diagram of a hearing aid system according to the invention for binaural supply.

The embodiment described in more detail below represents a preferred embodiment of the present invention.

In FIG. 2 is a hearing aid system with a left hearing aid 10 and a right hearing aid 20 for the binaural supply of a hearing aid wearer 30 shown schematically. The left hearing aid has to realize a directional microphone or to perform beamforming, blind-source separation and the like two microphones 11 and 12. The output signals of the microphones 11 and 12 are each a frequency divider 13, 14, respectively. Each of these two crossovers 13 and 14 has a low-pass output TP and a high-pass output HP. Instead of or in addition to the microphones 11 and 12, other signal input devices such. As a telecoil, a radio antenna and the like, are used.

The low-frequency components of the input signals from the crossovers 13 and 14 are fed to a binaural processing unit 15. At the same time, the low-frequency components are fed to a transmitter 16 integrated in the hearing device in order to transmit it wirelessly to the right-hand hearing device 20. Conversely, a receiver 17 receives the low-frequency portion of input signals of the right hearing aid and makes it available to the binaural processing unit 15. There, therefore, the low-frequency components of the input signals of the left hearing aid and the right hearing aid are processed together binaurally and it is a low-frequency output signal generated.

The high-frequency components of the crossovers 13 and 14 are fed to a monaural processing unit 18. This unit generates a high-frequency output signal and supplies it to an adder or a summarizing unit 19. It combines the high-frequency output signal of the monaural processing unit 18 with the low-frequency output signal of the binaural processing unit 15 to a common output signal SAL of the left hearing aid 10. This output signal SAL is optionally further processed or supplied to a handset (not shown).

The right hearing aid 20 is constructed symmetrically to the left hearing aid 10 with respect to the signal flow of interest here. It also has two microphones 21 and 22 whose signals are split with crossovers 23 and 24 in high-frequency and low-frequency components. The low-frequency components are, on the one hand, further processed by a binaural processing unit 25 and, on the other hand, transmitted by a transmitter 26 to the receiver 17 of the left-hand hearing device. A receiver 27 receives the low-frequency signals of the transmitter 16 from the left hearing aid 10 and makes them available for common processing with the low-frequency components of the right hearing aid 20 in the binaural processing unit 25.

The high-frequency components of the input signal are supplied by the crossover networks 23 and 24 to a monaural processing unit 28. As in the left hearing aid 10, the low-frequency output signal of the binaural processing unit 25 and the high-frequency output signal of the monaural processing unit 28 are then combined in a summary unit 29 into a common output signal SAR of the right hearing aid.

The two hearing aids 10 and 20 thus each have a communication device, namely a transmitter and a receiver 16, 17 and 26, 27 for bidirectional communication. In principle, of course, there would also be the possibility that only monodirectional communication with a transmitter on the one hand and a receiver on the other hand would be used if this is advantageous for the binaural supply. Correspondingly, a signal processing device (eg binaural supply unit 15 or 25) would then also be required only in a hearing aid.

Regarding the function of in FIG. 2 illustrated hearing aid system, it is according to the invention of importance that the input signals in two frequency ranges, for. As a low-frequency range below 1 to 2 kHz and a high-frequency range above about 1 to 2 kHz, are split. Only the low-frequency components are processed binaurally and transmitted to the other side, since the high frequency components can be satisfactorily processed only monaurally. After the respective parts have been processed binaurally or monaurally, they are subsequently combined to form two monaural output signals SAL and SAR.

An advantage of this splitting of the signal to be processed is that both for the processing and for the transmission of a lower data rate is necessary than in a broadband transmission or processing. In the specific example, only the low-frequency signals below about 1 to 2 kHz must be transmitted.

Another advantage of the binaural processing system is that there are few problems with microphone noise at low frequencies. The reason is that the microphone signals are exchanged in the low-frequency range between the left and right hearing aid and thus there is a large microphone distance, namely the distance from one head side to the other. This is especially important for differential directional microphones.

Another advantage of the presented system is that for monaural processing of the high frequencies under certain circumstances even smaller microphone distances than previously possible because monaural only higher frequency components are processed. The individual hearing aids can therefore be made more compact if necessary.

Claims (8)

Hearing system for the binaural supply of a user with - a first hearing device (10) including o a first signal input means (11, 12) for supplying a first input signal and o a first communication device (16, 17), as well as - a second hearing device (20) including o second signal input means (21, 22) for providing a second input signal, o second communication means (26, 27) for receiving a signal from the first communication means (16, 17) and o a second signal processing means (25) for processing signals of the second signal input means (21, 22) and the second communication means (26, 27) to a common output signal, wherein the signal transmitted by the first (16, 17) to the second communication device (26, 27) corresponds to a true spectral part of the total frequency spectrum of the first input signal, characterized in that - In the spectral part of the total frequency spectrum, the transmitted signal is processed binaurally together with a signal of the second signal processing means from the second signal processing means of the second signal processing means, while the signal of the second signal processing means is processed in the remaining part of the total frequency spectrum of the second hearing device monaural. The hearing aid according to claim 1, wherein the first hearing device (10) comprises first signal processing means (15) for receiving signals from the first signal input means (11, 12) together with signals from the first communication means (16, 17) originating from the second hearing device (20) to process to a common output signal. The hearing aid of claim 1 or 2, wherein the first and second signal input directions (11, 12, 21, 22) each comprise at least two microphones. Hearing aid according to one of the preceding claims, wherein in the signal transmission between the two communication devices (16, 17; 26, 27) exclusively a low-frequency component of the respective input signal is transmitted. Hearing aid according to claim 4, wherein the frequencies of the low-frequency component are less than 1 kHz or 2 kHz. Hearing aid according to one of claims 2 to 5, wherein in the first and / or in the second signal processing means (15, 25), a feedback reduction algorithm, a beam-forming algorithm or a blind-source separation algorithm is implemented, the signals from the each other hearing device (10, 20) uses. Method for processing signals for a binaural supply with a first and a second hearing device (10, 20),
by Providing a first input signal in the first hearing device (10), Providing a second input signal in the second hearing device (20), Transmitting a signal from the first (10) to the second hearing device (20), - processing the second input signal together with the signal from the first hearing device (10) in the second hearing device (20) to an output signal of the second hearing device (20), wherein the signal transmitted by the first (10) to the second hearing device (20) corresponds to a true spectral part of the total frequency spectrum of the first input signal, characterized in that - In the spectral part of the total frequency spectrum, the transmitted signal together with a corresponding spectral portion of the second input signal of the second hearing device (20) from the second hearing device (20) is processed binaurally, while the second input signal of the second hearing device (20) in the remaining part of the total frequency spectrum is monaurally processed by the second hearing device (20). The method of claim 7, wherein the signal that is transmitted represents only a low-frequency portion of the first input signal.

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