EP1909535A2 - Hearing device with controlled input channels and corresponding method - Google Patents

Abstract

The audio device has multiple input channel devices in every case for retaining and preprocessing a separate input signal, and for releasing a respective channel signal. A central computational device (DSP) for processing multiple channel signals of the input channel device. The multiple input channel device is controlled by the central computational device depending on two multiple channel signals. An independent claim is also included for a method for operating an audio device, which involves retaining and preprocessing a separate input signal in multiple input channel.

Description

The present invention relates to a hearing apparatus having a plurality of input channel devices each for receiving and preprocessing an input signal, and for outputting a respective channel signal and a central processing device for processing a plurality of channel signals of the input channel devices. Moreover, the present invention relates to a corresponding method for controlling a hearing device having a plurality of input channels. The term hearing device is understood in particular to mean a hearing device. In addition, the term also includes other portable and non-portable acoustic devices with multiple input channels.

Hearing aids are portable hearing aids that are used to care for the hearing impaired. In order to meet the numerous individual needs, different types of hearing aids such as behind-the-ear hearing aids (BTE), in-the-ear hearing aids (IDO), Concha hearing aids, etc. are provided. 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 standard integrated into a signal processing unit. This basic structure is shown in FIG 1 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 of the signal processing unit 3 is carried out by a likewise integrated into the hearing aid housing 1 battery. 5

Modern hearing aids usually have several input channels. Among other things, input channels may be provided via a microphone, a telecoil, a directional microphone, an audio shoe and a digital input. In the future, it is to be expected that additional input channels, for example for Bluetooth, wireless communication between hearing aids, etc., will be added. Which of these input channels is optimal depends on the situation. If, for example, an induction loop is present in the environment in which the hearing aid wearer is located, then optimally the telecoil should be selected as the input channel.

So far, the respective input channel usually had to be set manually. This is often a major problem, especially for older and very young hearing aid users. An improvement of this situation is a special mechanical solution in which an audio shoe is plugged into the hearing aid. Once plugged in, it will also be chosen as the input channel. Another example of automation is the automatic switching on of a telecoil by means of a reed relay as soon as a magnetic near field of the telephone acts on the reed relay.

In addition, in the document EP 1 484 942 A2 an automatic switching between a telecoil and a microphone using a signal classification described. Further, the patent discloses EP 0 989 775 B1 a hearing aid with a device for signal quality monitoring. The monitoring device determines the signal quality of the respective audio signal, for example, by comparison with a reference value that is specific for the relevant audio signal. Furthermore, the possibility is enumerated to insert into the artificially generated inductive, infrared, radio signals, etc., an identifier that can be detected by the monitoring device with little technical effort and that indicates that the signal in question has a suitable signal quality. Thus, the signal quality is determined in each case from the signal itself. This is basically a solution to the problem described above, but difficulties arise when, for example, working on the phone with the telecoil, at the same time a loud noise is introduced through the microphones and should be decided only on the basis of the level of each channel, whether is a useful signal.

In addition, the document describes DE 102 11 364 A1 the switching off of signal processing devices of a hearing aid. To reduce the power consumption, the hearing device has an internal or external hearing device signal source with a signal line for transmitting a signal to a hearing aid amplifier and a control device for switching on and off the hearing aid signal source. A monitoring logic is used to monitor the signal line and provide a switching signal to the control device so that the hearing aid signal source can be switched on and off on the basis of the switching signal. Auto-off occurs by reducing the termination resistance.

In addition, the document discloses EP 0 219 025 B1 a hearing aid with sound recording microphone assembly and handset, between an arrangement of a plurality of Sprachfrequenzselektierkanälen is turned on, which allows that come in a multi-channel system by continuous and mutual influence of control signals of adjacent channels only the strongest channels to fruition. The weaker ones are completely suppressed. For this purpose, an inhibition circuit is provided, by means of which, taking into account the signal strengths in the adjacent channels, strong channels are emphasized and weaker ones are suppressed.

The publication DE 10 2004 013 952 A1 further discloses a circuit arrangement comprising a plurality of filter stages of a filter bank, as well as a plurality of resonator circuits. Further, the circuit arrangement includes a resonator control circuit for controlling the quality of the resonator circuits. Each three of the resonator circuits are connected in series along a respective channel of the matrix-shaped arrangement, so that a respective output of an upstream resonator circuit is coupled to a respective input of a downstream resonator circuit. The resonator control circuit is in communication with all the resonator circuits. The quality of each of the resonator circuits is adjustable by means of the control circuit, the control circuit being arranged to adjust the quality of the resonator circuits in dependence on the amplitude of an output signal of the last resonator circuit of a respective channel.

The object of the present invention is therefore to automatically better adjust the signal quality with multiple input channels.

According to the invention, this object is achieved by a hearing device with a plurality of input channel devices each for recording and preprocessing a separate input signal and for outputting a respective channel signal and a central computing device for processing a plurality of channel signals the input channel devices, wherein at least one of the plurality of input channel devices is controllable by the central computing device in response to at least two of the plurality of channel signals.

In addition, according to the present invention, there is provided a method of controlling a multi-input channel hearing apparatus by recording and preprocessing a separate input signal in each of the plurality of input channels and outputting a respective channel signal from each of the plurality of input channels, and varying at least one of the channel signals of the plurality of input channels as a function of at least two of the multiple channel signals of the multiple input channels.

Advantageously, it is thus achieved that not only a single signal but several or all signals are taken into account for the control of the input channels. This significantly increases the signal quality.

Preferably, at least one input channel device or at least one component thereof can be switched off by the central computing device as a function of the plurality of channel signals. In this way, it can be achieved that only those components of the input channels are switched on and consume power that makes a significant contribution to the useful signal.

In another favorable embodiment, each channel signal is weighted by the central computing device in response to the plurality of channel signals. Thus, a frequency and time-specific weighting of the input channels taking into account the interaction of the individual channels with each other.

Furthermore, the quality of each of the channel signals or of each of the plurality of input channel devices can be a quality of the respective channel signal from the central computing device be determined so that the grades can be used to control the at least one input channel device. Thus, classifier results, signal-to-noise ratios, speaker verifications, modulation spectra, etc. can be included in the control of the input channels via a corresponding quality value.

FIG 1

einen schematischen Aufbau eines Hinter-dem-Ohr-Hörgeräts;

FIG 2

ein Blockschaltdiagramm der prinzipiellen Signalver-arbeitung eines erfindungsgemäßen Hörgeräts und

FIG 3

ein Blockschaltdiagramm eines Eingangskanals von FIG 1 im Detail.

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

FIG. 1

a schematic structure of a behind-the-ear hearing aid;

FIG. 2

a block diagram of the basic signal processing of a hearing aid according to the invention and

FIG. 3

a block diagram of an input channel of FIG 1 in detail.

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

The basic block diagram of a hearing aid reproduced in FIG. 2 shows a plurality of input channels IN1, IN2, IN3,..., INn. Connected thereto is in each case a corresponding preprocessing unit AW1, AW2, AW3,..., AWn for analyzing and weighting the output signals of the input channels IN1, IN2, IN3,..., INn. The corresponding audio signals are drawn with solid lines or arrows.

The output signals of the preprocessing units AW1 to AWn are summed in a subsequent summation device S frequency-specific and weighted. The resulting sum signal is analyzed in a digital signal processor DSP and further processed. Output signal of the digital signal processor DSP is an audio signal which is sent to the receiver or receiver R. From the sum signal the digital signal processor DSP continues to receive control signals which are fed back to the input channel devices IN1 to INn and the pre-processing units AW1 to AWn, respectively. In the present example, the feedback control signals, which are shown dotted, are first sent to the corresponding input channel device IN1 to INn and from there to the associated preprocessing unit AW1 to AWn.

In Figure 3, the waveform in an input channel to the digital signal processor DSP is shown in detail. The input channel device IN consists according to this example of an AD converter ADC, which optionally includes a further signal preprocessing. In addition, the input channel device IN has a control logic SL which, for example, drives the AD converter ADC to switch off.

After the input channel device IN, the audio signal, as in FIG. 3, is routed via an analysis and weighting unit AW to the summing circuit S and on to the digital signal processor DSP. In response to the summation signal, the digital signal processor DSP returns a control signal to the control logic SL of the input channel device IN. Since the control logic SL also controls the analysis and weighting unit AW in the selected example, it is possible to switch off these two units ADC and / or AW as a function of the summation signal by the digital signal processor DSP. Alternatively, the control logic of the analysis and weighting unit AW in response to the feedback signal to send a weighting signal or a corresponding control signal. In the event that one of the components SL, ADC and AW have been switched off, the control logic SL has an additional input, via which a control signal, which is contained for example in the input audio signal, can be recorded. This makes it possible, for example, to "wake up" the control logic SL or the components ADC and / or AW switched off by it.

The mode of operation of the signal processing units shown in FIGS. 2 and 3 is explained in detail below. Of essential importance is the feedback from the digital signal processor DSP, which is the central processing unit of the hearing aid, to the peripheral input channels. This means that the decision as to which channel is to be weighted or shut down is not a pure bottom-up process (eg threshold logic) but also a top-down process.

On the DSP, a frequency- and time-specific weighting of the input channels is carried out with the help of on the one hand the information that is present only in the DSP (not on the input channel) and on the other hand a linking of information about individual channels. This way of determining weights as a function of multiple input channels and central information is in contrast to determining weights solely on the basis of threshold logic that can only evaluate information from the particular single input channel.

In each frequency band and input channel a time-varying measure of the quality of the input channel is calculated. Depending on its quality, each input channel is time-weighted and "mixed" (added) with the other input channels. Optionally, by comparing the grades of the different channels, the "best channel" can be determined.

The centrally evaluated information for calculating the quality includes, for example, a classifier result. As a result, the same input channels are always used in certain situations. Thus, for example, in the listening situation "music" the use of a directional microphone or a telecoil is unlikely. Further information on the calculation of the quality can be provided by the signal-to-noise ratio (SNR). The smaller this is, the lower the quality.

A speaker verification can also be used to determine the quality. If a preferred speaker is recognized, which is individually trainable, this increases the quality. Furthermore, information from the modulation spectrum can contribute to the calculation of the quality. The stronger the modulations, the higher the respective quality.

A time-dependent weighting is calculated centrally in the digital signal processor DSP. In the control logic SL of each input channel, the central decisions are linked to the peripheral (eg threshold criteria).

The primary goal, especially for hearing aids, is to save energy. This can be achieved, for example, by determining the channel-specific information listed above by means of a broadband signal analysis. Thus, it is possible to dispense with a filter bank which consumes considerable power.

Another way of saving power is to turn off input channels or components thereof that do not contribute significantly to the payload. For example, a channel or a component can be switched off if a predefined threshold is not exceeded. Otherwise, if the threshold is exceeded, the corresponding signal is simply passed through.

Switching off unneeded components such as AD converter, signal analysis unit, demodulation unit, etc. can be realized according to the present example by the control logic SL. For this purpose, a mechanical logic can be used, which can be realized for example in the insertion of an audio shoe. When inserting the audio shoe is then z. B. the AD converter and the signal analysis unit turned on. Alternatively or additionally, the control logic may comprise analog threshold logic with which it is possible to activate only those channels whose signals exceed a certain amplitude.

However, the control logic for turning off certain components may also include a classifier control. This makes it possible to always use the same input channels in certain situations.

Channels or components thereof can only be switched off to the extent that a reactivation is always possible. For this purpose, an activation code (wake-up bit) can be used in the audio signal or in the control signal from the DSP.

The time-dependent weighting avoids abrupt switching and instead blends along the time or frequency axis between the various channels. For example, at some point in time, the fade-over may be limited to only one frequency band, in which frequency band from a first source, i. H. from a first input channel to a second source, d. H. a second input channel is blended.

In an advantageous manner, an optimal sound and / or an optimized speech understanding thus results at any time and fully automatically through the selection of the input channels according to the invention. In addition, by handling the input channels according to the invention, full compatibility with future external signal sources can be established. Another advantage is the low power consumption, which can be achieved by the automatic shutdown of components. Finally, with the control or regulation according to the invention, in particular by the signal analysis with SNR estimation and speaker verification, an individually optimal input channel can be determined.

Claims (8)

Hearing device with a plurality of input channel devices (IN, IN1, IN2, IN3, INn) each for receiving and preprocessing a separate input signal and for outputting a respective channel signal and a central processing device (DSP) for processing a plurality of channel signals of the input channel devices (IN, IN1, IN2, IN3, INn), characterized in that - At least one of the plurality of input channel devices (IN, IN1, IN2, IN3, INn) by the central computing device (DSP) in response to at least two of the plurality of channel signals is controllable. Hearing apparatus according to claim 1, wherein at least one input channel device (IN, IN1, IN2, IN3, INn) or at least one component thereof by the central processing device (DSP) in response to the plurality of channel signals can be switched off. Hearing apparatus according to claim 1 or 2, wherein each channel signal is weighted by the central processing unit (DSP) in dependence on the plurality of channel signals. Hearing apparatus according to one of the preceding claims, wherein from the central processing means (DSP) a quality of each of the channel signals or from each of the plurality of input channel means (IN, IN1, IN2, IN3, INn) a quality of the respective channel signal can be determined, and the qualities for the control the at least one input channel device (IN, IN1, IN2, IN3, INn) are used. A method for controlling a hearing device with a plurality of input channels (IN, IN1, IN2, IN3, INn) Recording and preprocessing a separate input signal in each of the plurality of input channels (IN, IN1, IN2, IN3, INn) and Outputting a respective channel signal from each of the plurality of input channels (IN, IN1, IN2, IN3, INn),
marked by - Varying at least one of the channel signals of the plurality of input channels (IN, IN1, IN2, IN3, INn) in response to at least two of the plurality of channel signals of the plurality of input channels (IN, IN1, IN2, IN3, INn). The method of claim 5, wherein at least one of the plurality of input channels (IN, IN1, IN2, IN3, INn) is turned off in response to the plurality of channel signals. The method of claim 5 or 6, wherein each channel signal is weighted in dependence on the plurality of channel signals. Method according to one of claims 5 to 7, wherein a quality of each channel signal is determined, and the grades are used for varying the at least one channel signal.

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