Method and device for configuring a user-specific hearing system

0001The present invention relates to a device as well as to a method for configuring a user-specific hearing system. Such a hearing system conventionally comprises a receiving unit for receiving sound events, a gain unit for frequency-dependent variable amplification of the received sound events, and a reproduction unit for reproducing the amplified sound events to the hearing element of a user.

0002In order to provide hearing impaired users with a better hearing, nowadays complex hearing systems are offered which amplify sound events and provide the amplified sound signals to the user on one or both sides of the ear. In order to optimize the supported hearing, it is necessary for the amplification characteristics of the hearing system to be adapted to the user-specific hearing impairment since a frequency-dependent deterioration of natural hearing is usually given so that a linear amplification of all sound events would not lead to the desired result. Modern hearing systems allow a frequency-dependent gain through a parameter setting,

0003In the <patcit id="pcit0001" dnum="EP1746859B1"><text>EP 1 746 859 B1</text></patcit> a method for configuring a hearing aid for a person is described. For this purpose, an audible tester generating an audible tones and an open headphone connected to the audiometer, worn by the patient, are used for transmitting the test tones. During the configuration, the user carries his hearing aid and the open headphones. The hearing aid is configured to amplify the signal delivered by the audiometer via the headphones frequency-specifically until the patient's hearing threshold is reached. In practice, however, it has been shown that the configuration of a hearing system by a frequency-specific amplification does not lead to satisfactory results until the hearing threshold of the user is reached. During the configuration of the hearing system, it is difficult for the user,

0004From the <patcit id="pcit0002" dnum="DE102007054152A1"><text>DE 10 2007 054 152 A1</text></patcit> a method for assessing the hearing ability of humans and for programming hearing aids is known. In this case, a test person is positioned in a test space at a distance from a loudspeaker array, whereupon test sounds are reproduced from the loudspeaker array, which represent virtual sound sources by means of wave field synthesis. The test person should then express themselves about the perceived volume of the heard test tones, so as to determine a sound image of the test person. The subjective feeling of the test persons with respect to the test sounds is compared with the hearing sensitivity of a normal hearing and a hearing image of the test patient is determined.

0005The <patcit id="pcit0003" dnum="DE102011104536A1"><text>DE 10 2011 104 536 A1</text></patcit> describes a method and a device for selecting and configuring a hearing aid for a patient. The patient is first subjected to a general screening to detect his hearing threshold. In the following, the patient is equipped with a hearing aid and irradiated with fixed signals of increasing loudness in a free sound field, until he can recognize that he has perceived signals. The hearing aid is preset on the basis of these findings. Subsequently, threshold values ​​for the auditory threshold, the pleasant auditory range and the discomfort range are set on the hearing aid.

0006In the <patcit id="pcit0004" dnum="US6201875B1"><text>US 6,201,875 B1</text></patcit> a method for adapting a hearing aid is described. Among other things, a stimulation set of pulses is provided, which comprises a plurality of loudness levels for a plurality of the frequencies. In a method step, each volume level for each frequency is compared with respect to the perceived equality. The sounds to be compared are provided by the hearing aid and not by a loudspeaker arrangement which simulates ambient conditions.

0007The object of the present invention is based on the prior art to provide an improved method and apparatus which allows a user-specific hearing system to be configured so that the user's listening experience is optimized after configuration. The method and the device should be designed as simply as possible in order to enable application in conventional enterprises of hearing aid acousticians and not to overwhelm the user during the configuration.

0008This object is achieved by a method according to the appended claim 1 or 4 as well as by a device according to the enclosed claim 7.

0009The invention is based initially on the approach that two adjacent sound events are compared, which are reproduced to the user one after the other. The first and the second sound event are evaluated by the user and the hearing system is adapted by the conversion unit by means of at least one conversion factor so that the loudness of the first sound event is perceived by the user of the hearing system equal to the loudness of the second sound event. Only by the use of adjacent frequencies, for example, at a distance of 1 kHz (+/- 100 Hz), the hearing system of the user is improved.

0010A device according to the invention for the configuration of a user-specific hearing system comprises a sound generator for generating sound events (hereinafter also referred to as sound signals) and a control unit. Preferably, at least one loudspeaker, which is spaced apart from the user of the hearing system, is provided for reproducing the sound events. Alternatively, the sound events can also be generated and reproduced by the hearing system. The control unit causes the sound generator, which can be formed in certain applications by the hearing system, in a predetermined sequence to generate several sound events with different frequencies. These can be narrow-band sinusoidal signals or also sound signals with a larger bandwidth. The generated sound events are controlled in a controlled manner, in particular amplified, by the control unit, and are sent to the loudspeaker unit for sound reproduction with the same loudness or reproduced directly by the hearing system. The control unit receives evaluation data via an operator interface, which represent a loudness difference perceived by the user between adjacent sound events occurring in the frequency range. Via the operator interface, the control unit is thus signaled as to whether the user perceives the sound events with the same loudness as loud or different loudly. The control unit then generates correction values ​​which are output and which are applicable to the hearing system in order to configure its converter unit,

0011In contrast to a system as described, for example, in the <patcit id="pcit0005" dnum="DE102007054152A1"><text>DE 10 2007 054 152 A1</text></patcit> according to the present invention, the loudspeaker (s) is placed at a distance of preferably 2 m from the user of the hearing system. A loudspeaker array is not necessary for the implementation of the invention, although it is possible. For the embodiment of the invention, it is also not necessary to record a sound audiogram. While conventional systems have as a rule only a fine adjustment of the hearing systems, the invention permits the complete configuration of the hearing system directly. In contrast to the prior art, a previous basic setting of the hearing system is not required. Likewise, a prior measurement of the audiological characteristics can be dispensed with.

0012Known systems, for example from the <patcit id="pcit0006" dnum="DE102011104536A1"><text>DE 10 2011 104 536 A1</text></patcit> known, used sounds close to the hearing threshold. When a hearing system is set up with such signals which are close to the threshold, there is the disadvantage that many parameters in the hearing system can lead to a distortion of the results. In addition, it is very difficult for the user to compare sounds that are close to each other. Instead, the present invention uses distinctly over-swelling tone signals, which are thus clearly audible to the normal listening user. Preferably, sound signals with a level of 45 - 80 dB are used.

0013According to a preferred embodiment, the sound events are generated by the sound generator as sinusoids, thirds or narrow-band noise.

0014Preferably, the operator interface comprises an input unit and a display unit which can be combined, for example, in a single device, such as a tablet PC.

0015According to a preferred embodiment, the device comprises a temporary data link between the control unit and the hearing system so that the correction values ​​can be transmitted directly to the hearing system. The data connection may be cable-bound or formed by wireless transmission systems. Alternatively, the correction values ​​can, of course, also be programmed into the hearing system via a further user interface.

0016The method according to the invention for the configuration of a user-specific hearing system starts with the step of reproducing a first sound event with a first frequency and a predetermined loudness on a loudspeaker, preferably on an at least two-channel loudspeaker unit having at least two loudspeakers spaced apart from one another and by the user of the hearing system. In the next step, the reproduction of a second sound event with a second adjacent frequency deviating from the first frequency and the same loudness as in the case of the first sound event takes place via the loudspeaker unit or the individual loudspeaker.

0017The aim of the method is achieved when all frequencies still audible by the user are matched to the curves of the same loudness.

0018Preferably, the aforementioned steps are repeated several times using differing, respectively adjacent frequencies of the respective sound events to be compared so that the hearing system can be configured over a predefined frequency range so that subsequently all the sound events with the same loudness are perceived by the user. The neighboring sound events, which are compared with each other, are each spaced apart by approximately 500 to 1200 Hz, ie, they are each preferably approximately 1 kHz ± 200 Hz, more preferably 1 kHz ± 100 Hz, although other differences in the above-mentioned Range are possible. The differences are preferably selected according to the parameter ranges of the hearing system to be adjusted. In the lower frequency range, ie below 1 kHz, the distances between adjacent sound events are preferably chosen to be smaller in order to be able to include several sound events with different, adjacent frequencies in the configuration loop in this area as well. In the higher frequency range, ie above 6 kHz, the distances between adjacent sound events are preferably selected to be able to be configured in this region with a manageable number of sound events with different, adjacent frequencies.

0019According to a modified embodiment, during the configuration, a multiple change occurs between the frequencies of the reproduced sound events and / or a stepwise approximation of the loudness of adjacent frequencies to the same level.

0020In an extended embodiment, the device according to the invention is completely automated. For this purpose, the procedure is adapted in such a way that the acoustician no longer has to make any special inputs to the hearing system. Instead, only the results are read in according to the loudness sensations of the user and implemented directly in the hearing system.

0021In order to calibrate the device according to the invention, the space in which the loudspeakers are set up and the sound events are reproduced can be measured with a white noise by means of a level meter and a frequency analyzer. The aim is to adjust the loudspeakers to the environment, so that each loudspeaker delivers exactly the same level at the end of the calibration up to the usual tolerances. If a reduced design is used with only one loudspeaker, the same must be calibrated as well. If all loudspeakers are adjusted accordingly, the individual tone or frequency bands are preferably adjusted according to the standard ISO 226: 2003 using a level meter. The aim of the calibration is high reproducibility in all room sizes.

0022According to a further modified embodiment, the sound events themselves can also be generated and reproduced by the hearing system itself. The hearing system provided to the user can thus be the sound generator itself. In this variant, the free sound field is dispensed with, since the reproduction of the sound events via the loudspeaker system is omitted, but this results in a particularly simple construction of the device according to the invention.

0023Further details, modifications and advantages of the present invention will become apparent from the following description of preferred embodiments, with reference to the drawing. Show it:<dl id="dl0001"><dt>FIG. 1:</dt><dd>1 shows a schematic representation of a first embodiment of a device according to the invention for configuring a user-specific hearing system;</dd><dt>FIG. 2:</dt><dd>1 shows a simplified flowchart of a first embodiment of a method according to the invention for configuring a user-specific hearing system;</dd><dt>Figures 3a-3c:</dt><dd>4 is a simplified flow diagram of a second embodiment of the method according to the invention;</dd><dt>FIG</dt><dd>2 shows a schematic representation of a second embodiment of the device for configuring a user-specific hearing system.</dd></dl>

0024In the <figref idrefs="f0001">FIG</figref> shows essential components of the device according to the invention for configuring a user-specific hearing system as well as their interaction. The user-specific hearing system 01, which as such is not part of the device according to the invention, comprises one or two hearing devices as subsystems, each having a receiving unit for receiving sound events, a converter unit for frequency-dependent variable adaptation of the received sound events, and a reproduction unit for reproducing the amplified sound events Hearing member of a user 02.

0025For example, the hearing system 01 is a so-called deep-fit ​​earmold or deep-fit ​​CIC hearing aid. The auditory path of the user is closed as far as possible by an inserted earmold, so that only the sound events amplified by the hearing system 01 are fed to the internal auditory organ of the user 02. In such systems, the converter unit is formed by a amplification unit, which amplifies the received sound events variably in a frequency-dependent manner.

0026However, modified embodiments of hearing systems can also be configured. The received sound events are not necessarily amplified by such modified hearing systems, but are processed / adapted in a broad sense and supplied, for example, as electrical signals to the hearing element.

0027The device according to the invention further comprises a sound generator 03, which in the illustrated embodiment consists of a system computer and an amplifier. The sound generator 03 generates sound events (sound signals) and passes them on to a loudspeaker unit 04, through which sound events are emitted. The loudspeaker unit 04 is constructed in the illustrated embodiment in two or more channels and has at least two loudspeakers, which are positioned at a distance from one another and at a distance from the user 02. The spacing ratios preferably lead to a position of the user in the free sound field suitable for a realistic stereo listening experience. The user 02 is thus in the free sound field so that the sound events reach him as in a natural sound environment.

0028In the case of modified, simple embodiments, the sound events can also be reproduced by only a single loudspeaker.

0029Finally, the device according to the invention comprises a control unit 05. The control unit 05 causes the sound generator 03 to generate a plurality of sound signals with different frequencies in a predetermined sequence. The generated sound signals are amplified in a predetermined manner and sent to the loudspeaker unit for sound reproduction with the same loudness. Standardized measuring methods for measuring the loudness are, for example, given in DIN 45631 and ISO 532 B.

0030In the simplest case, the user is thus given a first sound event with a frequency of, for example, 2 kHz and a loudness of 65 dB via the loudspeaker unit, and immediately thereupon a second sound event with an adjacent frequency of 3 kHz and the same loudness. A normal listening user would feel the two sound events as being the same, while a user with a hearing loss in the affected frequency range registers a difference in the loudness. The sound events are reproduced specifically above the user's hearing threshold, in a range of normal ambient loudness, for example, at 45 to 80 dB. A loudness difference perceived by the user is entered either by the user 02 or by a hearing aid acoustician 06 performing the configuration via an operator interface on the control unit 05. The control unit 05 determines correction values ​​from the received assessment data for the loudness difference and outputs these to adjust the converter unit of the hearing system 01 in such a way that the loudness difference is reduced or preferably completely eliminated. The correction values ​​can either be fed directly into a programming unit 07, which sets the frequency-dependent amplification of the hearing system 01. Alternatively, the correction values ​​can be displayed to the hearing healthcare professional so that the latter can enter the corresponding corrections manually into the programming unit 07 via a further interface.

0031A further modified embodiment uses the hearing system itself as a sound generator as well as for the reproduction of the sound events. The loudspeaker system can be dispensed with.

0032In <figref idrefs="f0002">FIG</figref> the essential steps for carrying out a method according to the invention for configuring a user-specific hearing system are shown in the form of a program flowchart. Before starting the actual configuration, the hearing system can be adjusted with the manufacturer's basic setting (First Fit), without any additional exposure to frequency-dependent gain parameters. If the user is supplied with hearing systems on both ears, they are coupled, and in the case of the two-channel loudspeaker unit, only the side is subjected to a sound event which is closest to the better hearing ear of the user. The actual configuration then begins with the reproduction of a first sound event with a first frequency, for example 2 kHz, in a clearly perceptible volume, for example with a loudness of 65 dB, initially only on one channel of the two-channel loudspeaker unit, on the side of the better hearing ability of the user. A second sound event with a second, adjacent frequency, for example, 3 kHz and the same loudness is reproduced immediately thereafter, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. initially only on one channel of the two-channel loudspeaker unit, on the side of the better hearing ability of the user. A second sound event with a second, adjacent frequency, for example, 3 kHz and the same loudness is reproduced immediately thereafter, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. initially only on one channel of the two-channel loudspeaker unit, on the side of the better hearing ability of the user. A second sound event with a second, adjacent frequency, for example, 3 kHz and the same loudness is reproduced immediately thereafter, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. on the side of the better hearing ability of the user. A second sound event with a second, adjacent frequency, for example, 3 kHz and the same loudness is reproduced immediately thereafter, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. on the side of the better hearing ability of the user. A second sound event with a second, adjacent frequency, for example, 3 kHz and the same loudness is reproduced immediately thereafter, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. adjacent frequency, for example, 3 kHz and the same loudness, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. adjacent frequency, for example, 3 kHz and the same loudness, also on the side of better hearing. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user. The user registers either the same loudness or a loudness difference despite the objectively existing identical loudness between the two reproduced sound events. Via an operator interface, a perceived loudness difference can be entered in the form of evaluation data of the control unit of a corresponding device, in the simplest case only by selecting the sound event perceived as loud by the user.

0033In the case of a determined loudness difference, an amplification factor of the amplification unit (or a corresponding adaptation parameter of a modified converter unit) of the hearing system is changed in the next step, so that the loudness of the first sound event is perceived by the user of the hearing system equal to the loudness of the second sound event. The hearing system is thus configured for the frequency range between the frequencies of the two neighboring sound events which are reproduced.

0034The hearing system is preferably configured not only for two sound events, which are spaced apart from one another in their frequencies, ie are mutually adjacent, but for a plurality of sound events which differ from each other by a predetermined amount, ie are respectively adjacent to one another, for example with a frequency spacing in the range between 500 and 1200 Hz.

0035<figref idrefs="f0003 f0004 f0005">FIGS. 3a-3c</figref> show a correspondingly modified embodiment of the method for configuring a user-specific hearing system in which the configuration is performed using more than two sound events.

0036The <figref idrefs="f0003">FIG. 3a</figref> section "Adjustment better ear" corresponds to the already explained steps according to <figref idrefs="f0002">FIG</figref>, whereby several sound events with different frequencies are used. The hearing devices of the user are initially operated in the basic setting, adaptive parameters are switched off. If the user uses two hearing aids, they are coupled and one side (a subsystem) is switched off. In the next step, a first sound event is reproduced with, for example, 2 kHz, 65 dB, so that the user perceives this first sound event with a clear loudness. In the next step, the user is given a second sound event with an adjacent frequency of, for example, 3 kHz and the same loudness as the first sound event. The user can directly compare the two sound events with adjacent frequencies and the same loudness, whether the second sound event is perceived louder or quieter. In the case of a deviation in the subjectively perceived loudness, a correction value / amplification factor is applied so that the user then perceives about the same loudness. The selection of the correct amplification factor can optionally be effected successively in several partial steps. A comparison is then made between adjacent frequencies, for example, 3 and 4 kHz, 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, correction values ​​for the hearing aid being determined for the respective two sound events of adjacent frequencies Loudness. Further steps in the lower frequency range can be followed by comparison of sound events at, for example, 2 and 1 kHz, as well as 1 kHz and 500 Hz. In the case of a deviation in the subjectively perceived loudness, a correction value / amplification factor is applied so that the user then perceives about the same loudness. The selection of the correct amplification factor can optionally be effected successively in several partial steps. A comparison is then made between adjacent frequencies, for example, 3 and 4 kHz, 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, correction values ​​for the hearing aid being determined for the respective two sound events of adjacent frequencies Loudness. Further steps in the lower frequency range can be followed by comparison of sound events at, for example, 2 and 1 kHz, as well as 1 kHz and 500 Hz. In the case of a deviation in the subjectively perceived loudness, a correction value / amplification factor is applied so that the user then perceives about the same loudness. The selection of the correct amplification factor can optionally be effected successively in several partial steps. A comparison is then made between adjacent frequencies, for example, 3 and 4 kHz, 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, correction values ​​for the hearing aid being determined for the respective two sound events of adjacent frequencies Loudness. Further steps in the lower frequency range can be followed by comparison of sound events at, for example, 2 and 1 kHz, as well as 1 kHz and 500 Hz. so that the user then perceives about the same loudness. The selection of the correct amplification factor can optionally be effected successively in several partial steps. A comparison is then made between adjacent frequencies, for example, 3 and 4 kHz, 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, correction values ​​for the hearing aid being determined for the respective two sound events of adjacent frequencies Loudness. Further steps in the lower frequency range can be followed by comparison of sound events at, for example, 2 and 1 kHz, as well as 1 kHz and 500 Hz. so that the user then perceives about the same loudness. The selection of the correct amplification factor can optionally be effected successively in several partial steps. A comparison is then made between adjacent frequencies, for example, 3 and 4 kHz, 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, correction values ​​for the hearing aid being determined for the respective two sound events of adjacent frequencies Loudness. Further steps in the lower frequency range can be followed by comparison of sound events at, for example, 2 and 1 kHz, as well as 1 kHz and 500 Hz. 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, whereby in each case correction values ​​for the hearing aid are determined, which lead to the perception of the respective two sound events of adjacent frequencies with the same loudness. Further steps in the lower frequency range can be followed by comparison of sound events at, for example, 2 and 1 kHz, as well as 1 kHz and 500 Hz. 4 and 5 kHz, 5 and 6 kHz as well as 6 and 8 kHz, whereby in each case correction values ​​for the hearing aid are determined, which lead to the perception of the respective two sound events of adjacent frequencies with the same loudness. Further steps in the lower frequency range can be followed by comparing sound events at, for example, 2 and 1 kHz and 1 kHz and 500 Hz.

0037In the following sections of the flow chart according to <figref idrefs="f0004">3b</figref> and <figref idrefs="f0005">3c</figref> the steps necessary to configure the second hearing system (on the second ear) are also shown (section "Two-Sided Adjustment") and for a final adjustment of the hearing systems with respect to the setting of the perception threshold and the setting of the maximum amplification of the hearing systems can be executed additionally. Both hearing systems of the user are preferably binaurally coordinated with one another by exchanging the sound events.

0038How <figref idrefs="f0004">3b</figref> , the coupling of the two hearing aids is first switched off in the section "Two-sided adjustment". All further gain settings are made in this section only on the connected side (hearing aid). The second hearing aid that is connected to the hearing aid is first supplied with a sound event with 2 kHz, 65 dB. The adjustment takes place in all further frequencies, as described above.

0039Subsequent settings in the section "Volume adjustment", in the section "Loud level" and in the section "Output level" (<figref idrefs="f0005">3c</figref>).

0040<figref idrefs="f0006">FIG</figref> 10 shows a modified embodiment of the device for configuring a user-specific hearing system 01a. Here, the hearing system itself is used as a sound generator as well as for the reproduction of the sound events. In this case, the adapted user-specific hearing system 01a also comprises one or two hearing devices as subsystems each comprising a receiving unit for receiving sound events, a converter unit for the frequency-dependent variable adaptation of the received sound events, and a reproduction unit for reproducing the amplified sound events to the hearing organ of a user 02 , In addition, the hearing system 01a or each subsystem comprises an integrated unit, which functions as a sound generator and is activated by the control unit 05. The integrated sound generator generates sound events and reproduces them directly by means of the playback unit of the hearing system 01a. The control unit 05 causes the hearing system to generate, in a predetermined sequence, a plurality of sound signals with different frequencies and to reproduce them with the same loudness. A loudness difference perceived by the user 02 is entered either by the user or by a hearing aid acoustician 06 performing the configuration via an operator interface on the control unit 05. The control unit 05 determines correction values ​​from the received assessment data for the loudness difference and outputs these to adjust the converter unit of the hearing system 01 in such a way that the loudness difference is reduced or preferably completely eliminated.

<u>LIST OF REFERENCE NUMBERS</u>

0041<dl id="dl0002" compact="compact"><dt>01</dt><dd>- Hearing system</dd><dt>02</dt><dd>- Users</dd><dt>03</dt><dd>- Sound generator</dd><dt>04</dt><dd>- Speaker unit</dd><dt>05</dt><dd>- Control unit</dd><dt>06</dt><dd>- Hearing Aids</dd><dt>07</dt><dd>- Programming unit</dd></dl>