JP2008271549A5 - - Google Patents

Description

Listening device, listening system, and operating method of listening device

The present invention relates to a hearing device comprising a transmission unit for performing Oite wireless data transmission to the main frequency band, and a speaker, and an actuating device for actuating the speaker by the operation signal. The invention further relates to a method for operating a listening device. The term “ listening device ” here means in particular hearing aids, headsets, headphones and other devices that can be worn on the head.

  Hearing aids are wearable listening devices used for the treatment of hearing impaired people. In order to meet a large number of individual requirements, hearing aids come in a variety of structural types, such as ear-hung hearing aids (HdO) and ear canal hearing aids (IdO), and for example, Concha hearing aids or canal hearing aids. (CIC) is available. An exemplary hearing aid is worn in the outer ear or in the ear canal. Furthermore, bone conduction hearing aids, implantable or vibrotactile hearing aids are also used on the market. In so doing, the impaired auditory stimulation is performed mechanically or electrically.

  Hearing aids in principle have an input transducer, an amplifier and an output transducer as essential components. The input transducer is typically at least one of a sound receiver such as a microphone and an electromagnetic receiver such as an induction coil. The output transducer is most often realized as an electroacoustic transducer, for example a small speaker, or as an electromechanical transducer, for example a bone conduction receiver. The amplifier is usually integrated in the signal processing unit. This principle structure is shown in FIG. 1 for an example of a hook-on hearing aid. In the hearing aid housing 1 for wearing after the ear, one or more microphones 2 are incorporated for taking sounds from the surroundings. Similarly, the signal processing unit 3 incorporated in the hearing aid housing 1 processes the microphone signal and amplifies it. The output signal of the signal processing unit 3 is transmitted to a speaker or receiver 4, and the speaker or receiver outputs an acoustic signal. In some cases, the sound is transmitted to the eardrum of the hearing aid wearer via an acoustic tube that is fixed in the ear canal by otoplasty. The power supply of the hearing aid and in particular the signal processing unit 3 is likewise effected by a battery 5 incorporated in the hearing aid housing 1.

  For example, pulse density modulation (PDM) or pulse width modulation (PWM) is often used to operate a hearing aid speaker or handset. Digital operation has the advantage that the digital-to-analog converter stage can be eliminated in the digital hearing aid. Digital actuation circuits also have a significantly higher efficiency than analog actuation circuits. In contrast, analog operating circuits are less disturbing, that is, analog operating circuits have a few harmonic components in the frequency spectrum limited to acoustic signals. Highly prominent harmonics in digital operation are wireless transmission of data between hearing aids and between hearing aids and external accessories (remote controls, wireless programming devices, wireless relay devices, etc.) It becomes an obstacle.

  One possible solution to this problem may be in the following compromise. That is, in the hearing aid having wireless transmission, the handset is operated in an analog manner, and in the hearing aid having no wireless function, digital operation is performed to save current. However, hearing aids with wireless transmission along with them cannot benefit from digital actuation that saves current.

It is therefore an object of the present invention to enable a digital operation that saves the current of the speaker of the listening device, especially for a listening device that functions digitally. Furthermore, it is providing the method of operating a listening apparatus.

This object according to the present invention, the hearing device comprising a transmission apparatus for transmitting data of Oite wireless, and speaker, and an actuating device for actuating the actuating signal speakers to the main frequency band, operating frequency spectrum of the signal is resolved by having a substantial notch area in the range of the main frequency band.

Further according to the invention, performs data transmission Oite wireless in the main frequency band, a method of operating a hearing device by more activating the speaker listening device actuation signal is provided, the frequency of its time working signal spectrum has a substantial notch area in the range of the main frequency band.

By separating the signals for data transmission and speaker operation in the frequency range , there is little mutual interference, and as a result, the listening device configured for wireless data transmission also digitally connects the internal handset or speaker. Can be operated.

  Advantageously, the actuating signal of the actuating device is pulse density modulated or pulse width modulated. Thereby, the inductive speaker acting as a low-pass filter can be operated without the high signal processing cost of the digital signal processing circuit.

Data transmission by the transmission apparatus can be performed in a plurality of frequency bands in the broadband and the frequency spectrum of the actuation signal may have a respective substantial notch region Oite the range of each frequency band. In addition, the principle according to the invention can also be used for high throughput broadband transmission.

Further, the transmission apparatus may include a band pass filter that basically passes only the frequency components in the main frequency band, or only the frequency components in the main frequency band and several times its range . Thereby, the disturbance stability of radio transmission is further enhanced.

  The listening device according to the invention can be formed as an auditory canal type hearing aid in a special embodiment, even if current consumption and freely available places are extremely limited. . That is, the handset that is typically a magneto-acoustic transducer is very close to the receive coil due to the small amount of space provided. Furthermore, in ear canal type hearing aids, the position and orientation is unique for each device. In any case, the handset induces a more or less large disturbance signal in the receiving coil. At the same time, the signal-to-noise ratio is usually clearly reduced. Although a bad signal-to-noise ratio can be improved by increasing the transmit power, it can only be achieved by a very large energy demand. Therefore, the solution according to the invention of spectrally separating the activation signal for the handset from the transmission signal for wireless data transmission is increasingly advantageous.

  Corresponding to another embodiment, according to the present invention, there is provided a listening system comprising two hearing aids each having the configuration of the above-described listening device, wherein the transmission devices of both hearing aids enable two-way wireless transmission. The data transmission in one direction is performed in a different frequency band from the data transmission in the other direction. Thereby, a true bidirectional connection with simultaneous directional transmission can be freely used.

  The present invention will be described in detail with reference to the drawings. The examples described below illustrate advantageous embodiments of the invention.

  In FIG. 2, a schematic of a hearing aid system with two hearing aids 10 and 11 is shown. Both hearing aids 10 and 11 are formed in the same manner. However, only the hearing aid 10 shows essential components for the present invention for the sake of clarity. The central unit of the auditory canal-type hearing aid 10 is a signal processing or control unit 12. It is powered by the battery 13. The output signal of the control unit 12 is used to activate a handset 14, which is typically formed as a magnetoacoustic transducer. Furthermore, the control unit 12 also activates the transmission unit 15, which is used here for bidirectional transmission to the second hearing aid 11. The transmission unit 15 is symbolically indicated by a coil, but can also include other transmission components.

  From FIG. 2 it can be seen that the electronics components in the auditory canal-type hearing aid 10 are arranged very close to each other in space. In particular, the handset 14 and the transmission unit 15 are also located very close together, resulting in unintentional mutual influence and interference.

  FIG. 3 shows a typical PDM activation signal which causes the activation unit 12 to activate the handset 14 in time. Information to be transmitted to the handset lurks in the pulse density. FIG. 4 shows an enlarged view of one end of this signal. The density of the impulse varies in the desired manner.

  The handset 14 has a unique inductive characteristic. Therefore, the temporal PDM voltage signal depicted in FIG. 3 results in a current profile drawn in broken lines in the figure at the handset.

The frequency spectrum of the PDM voltage signal of FIG. 3 is shown in FIG. The spectrum consists essentially of arcuate curves, which are periodically aligned and whose amplitude decreases according to the function sin x / x based on the rectangular shape of the PDM pulse. In a specific range of the spectrum, i.e. between the two curves, a notch E, i.e. a so-called "removed area" occurs in the spectrum. In this removed area, no or little interference signal is generated. Only the effective signal N or the effective signal component N ′ is present there. The occurrence of the notch (cut) E can be explained as follows. That is, the pulse duration Tp of the PDM signal is fixedly selected and appears in a fixed time raster of n × Tp. The statistical distribution of positive and negative pulses is the same for natural audio signals. Thereby, the frequency 1 / (2 Tp) and its integer multiple appear at phases 0 ° and 180 ° with substantially the same amplitude. This leads to a targeted loss of signal in the range around the frequency n × 1 / (2Tp). This disappearance results in the above-described notches or notches E. An arch-shaped interference signal component S is generated between the notches.

The basic concept of the present invention is to adapt the operating frequency of digital handset operation to a wireless transmission system. Specifically, therefore, an attempt is made to remove the disturbing handset noise component from the frequency band used for the wireless data transmission system. This means that in this case just the operating frequency of the PDM modulator is chosen so that the notch E is in the range of the transmission frequency for radio transmission or several times that frequency, so that the interference spectrum is advantageously adjusted. Achievable by formation (noise shaping). Thereby, the radio transmission is only slightly disturbed and the advantages of digital handset operation are retained.

Removing the disturbing component from the frequency range used for wireless data transmission can be supplemented by another known “noise shaping” method. For example, the noise component can be shifted from the low frequency range of the audio signal to higher frequencies in a known manner. By this and other known methods, the width and shape of the previous notches or notches can be optimized.

The signal processing of the radio transmission component is performed by a bandpass filter that passes unimpeded only the frequencies within the bandwidth used for radio, thereby further improving the jamming stability against receiver operation of radio transmission. . The filter function F of such a band pass filter is shown in FIG. 6 together with the PDM frequency spectrum of the exemplary signal. Improving jamming stability is particularly useful when the characteristics of bandpass (filter edge slope, filter quality) and “noise shaping” characteristics are compatible with each other.

In the example of FIG. 5, notches occur at fixed frequency intervals. In the simplest case, only one of them is used for wireless data transmission. For applications requiring a large bandwidth, the wireless transmission can be divided into a plurality of partial frequency ranges . In that case, the partial frequency range should be in the other notch of the PDM activation signal for the handset. With regard to the disturbance stability, the bandpass characteristic and the “noise shaping” characteristic should also be matched to each other. This is achieved, for example, by a unique comb filter whose passband is adjusted to a notch.

  After filtering, a flat and low basic noise level is obtained, from which small effective signals can still be detected well. As a result, the reachable range for wireless transmission increases. Instead, higher throughput is achieved for the same reach.

It has already been suggested above that bandwidth intensive transmission of audio signals or programming data is possible for applications where multiple frequency ranges are utilized. In some cases, multiple frequency bands can be utilized for simultaneous bi-directional transmission by distributing directions to different frequency ranges .

It is a principle block diagram of the hearing aid by a prior art. It is a block diagram of the hearing aid system by this invention. FIG. 4 is a diagram of a PDM time signal of a handset voltage. FIG. 4 is a partially enlarged view of the PDM time signal of FIG. 3. FIG. 4 is a diagram of the PDM frequency spectrum of the signal of FIG. FIG. 6 is a diagram illustrating the PDM frequency spectrum of FIG. 5 along with a pass curve of an ideally adapted frequency filter.

DESCRIPTION OF SYMBOLS 1 Hearing aid housing 2 Microphone 3 Signal processing unit 4 Handset 5 Battery 10, 11 Hearing aid 12 Control unit 13 Battery 14 Handset 15 Transmission unit E Notch
N Effective signal N 'Effective signal component S Interfering signal component

Claims (10)

A transmission device for data transmission Oite wireless in the main frequency band (15), a speaker (14), hearing device comprising an actuating device for actuating the speaker (14) by actuation signal (12) In (10),
Hearing device, characterized in that the frequency spectrum of the actuation signal has a substantial notch area in the range of the main frequency band.   2. The listening device according to claim 1, wherein the actuation signal of the actuation device (12) is pulse density modulated. The data transmission by the transmission device (15) is performed in a plurality of frequency bands in a wide band, and the frequency spectrum of the operation signal has a substantial notch region in each frequency band range. Listening device. The transmission device (15) has a band-pass filter that basically passes only frequency components in the main frequency band or only frequency components in the main frequency band and integer multiples thereof. 4. The listening device according to any one of 3.   The hearing device according to claim 1, wherein the listening device is formed as an ear canal insertion type hearing aid.   6. A hearing system comprising two hearing aids (10, 11) each having the configuration of a hearing device according to any one of claims 3 to 5, wherein the transmission device (15) of both hearing aids (10, 11) is a two-way radio. A listening system characterized in that data transmission is possible and data transmission in one direction is performed in a different frequency band from data transmission in the other direction. Performs data transmission Oite wireless in the main frequency band, by actuating the actuation signal speakers (14) of the hearing device, the method of operating a hearing device (10, 11),
A method for operating a listening device, characterized in that the frequency spectrum of the actuation signal has a substantial notch region (E) in the range of the main frequency band.   The method of claim 7, wherein the actuation signal is pulse density modulated. The method according to claim 7 or 8, characterized in that data transmission is performed in a plurality of frequency bands over a wide band, and the frequency spectrum of the actuation signal has a substantial notch region (E) in each frequency band range . The signal for data transmission is filtered by band pass that basically passes only frequency components in the main frequency band or only frequency components in the main frequency band and integer multiples thereof. The method according to any one of 7 to 9.