Device for remotely calibrating an audiometer

Abstract

The invention relates to a device (1) for remotely calibrating an audiometer (2), wherein the device (1) comprises a first interface (1a) for connecting the device (1) to the audiometer (2) and / or a second interface (1) for connecting the device (1) to at least one sound converter (3), wherein the device comprises a remote communication device (4) for remote communication with a control device (5), spatially spaced apart from the device (1), for controlling and / or receiving measured values from the device (1).

Description

[0001] Device for remote calibration of an audiometer

[0002] The invention relates to a device for remotely calibrating an audiometer, wherein the device has a first interface for connecting the device to the audiometer and / or a second interface for connecting the device to at least one sound transducer. Furthermore, the invention also relates to an arrangement comprising an audiometer, at least one sound transducer, an operating device, in particular a computer, and such a device, as well as to a method for remotely calibrating an audiometer using such a device.

[0003] An audiometer is a device for determining human hearing ability and speech intelligibility, discomfort thresholds, determining the effectiveness of hearing protection, and much more. The audiometer can emit defined tones via sound transducers, such as air conduction earphones, insert earphones, bone conduction earphones, and / or loudspeakers, which are then played back to a patient. In audiology, this is also referred to as presentation. To ensure that the tones emitted correspond to the specifications and thus enable a correct diagnosis, audiometers must generally be tested or calibrated annually. Procedures and systems for testing audiometers are subject to the ISO 60645 standard series, the Medical Device Operator Ordinance, and the MM11 guideline of the Physikalisch-Technische Bundesanstalt (PTB). The testing and calibration is carried out in accordance with the state of the art.Calibration of audiometers in a so-called "on-site" procedure. The audiometer is checked or calibrated on-site by a calibration service provider. This means that a technician from the calibration service provider travels to the location of the audiometer, for example, an acoustician or ENT doctor, and carries out the necessary steps to check or calibrate the audiometer. Such a procedure is shown as an example in Fig. 2 and is explained in more detail in the figure description.

[0004] Such an "on-site" procedure has several disadvantages, the most significant of which is the technician's long travel time and the actual time required to check or calibrate the audiometer. The average travel time is approximately one to three and a half hours, depending on the location of the audiometer. Calibrating or checking the audiometer, on the other hand, takes only one and a half hours. Thus, the travel time usually exceeds the technician's actual working time.

[0005] This negatively impacts the efficiency of inspections and calibrations. Furthermore, customers who utilize the services of the calibration service manager also incur travel costs for the technician.

[0006] Furthermore, complex route planning is necessary so that a technician can visit as many audiometers as possible to be checked or calibrated at various locations in the shortest possible time. This also creates a fixed schedule that both the customer and the technician must adhere to. For the sake of completeness, the so-called "SWAP" procedure should also be mentioned. In this "SWAP" procedure, the sound transducers of the audiometer are simply exchanged. Since the frequency-dependent sensitivity, i.e., the transmission factor, is different for each sound transducer, exchange cannot be carried out simply.

[0007] A possible replacement is only possible for transducers equipped with a TEDS chip (Transducer Electronic Data Sheet Chip). Calibration data (e.g., the frequency response) is stored on a chip in the transducer connector. However, this is still completely inadequate, as the audiometer's output is not calibrated. Therefore, the entire measurement chain / transducer chain / signal path would not be calibrated. A deviation in the output cannot be verified.

[0008] Overall, the "SWAP" method does not meet the requirements of the ISO 60645 standard series, the Medical Device Operator Ordinance, and the Will Guideline of the Physikalisch-Technische Bundesanstalt (PTB). Therefore, such a method is not suitable for calibrating an audiometer within the meaning of the present application.

[0009] The object of the invention is to provide a device for remote calibration of an audiometer that is improved over the prior art, in particular with which an audiometer can be calibrated in a particularly simple manner. Furthermore, an arrangement comprising an audiometer, at least one sound transducer, an operating device, in particular a computer, and such a device, as well as a method for remote calibration of an audiometer using such a device, are to be provided. These objects are achieved by the features of claims 1, 5, and 10.

[0010] According to the invention, it is therefore provided that the device comprises a remote communication device for remote communication with an operating device spatially spaced from the device for operating and / or receiving measured values ​​dex* device.

[0011] The remote communication device allows the technician to operate the device for remote calibration of an audiometer via the control unit or to receive measured values ​​from the device and use them for control or calibration.

[0012] This can be done, for example, via a "Team Viewer connection."

[0013] The control unit can be located at a calibration service provider's location, for example, while the device can be used to calibrate audiometers at locations remote from the calibration service provider's location, such as at a customer's location. For this purpose, the device only needs to be transported to the audiometer location, which can easily be done by a shipping service provider, for example.

[0014] This eliminates travel time for the calibration service provider's technician. They only need to calibrate the audiometer remotely.

[0015] This increases efficiency by eliminating long travel times. The device can be transported early enough, eliminating waiting times and other inconveniences. Eliminating travel also reduces costs for customers, as they only have to pay for the device's transport, not the technician's travel.

[0016] Especially when only a defective transducer needs to be replaced, the ratio between travel time and on-site service is even more unbalanced, since changing the headphones and calibration usually takes no more than 30 to 45 minutes. This problem is also solved by a method according to the invention, which allows the transducer to be simply shipped.

[0017] Costs are also reduced for the calibration service provider, as there are no longer any costs for a car or overnight accommodation for the technician.

[0018] Furthermore, flexible scheduling is possible, as appointments no longer need to be planned according to routes. For example, calibration can be performed at an appointment for which a customer's patient has not shown up. Furthermore, checks and calibrations can also be performed at short notice, as route planning is no longer necessary.

[0019] Furthermore, the environmental impact can be reduced, since the CO2 emissions and particulate matter pollution from transporting the device by a shipping service provider are significantly lower than if the technician had to travel there.

[0020] Ultimately, there are also positive effects for the technicians of a calibration service provider. For example, the physical and psychological stress associated with driving is eliminated or can be reduced. This also eliminates the need for long journeys.

[0021] Hotel stays lasting weeks

[0022] Inspection trips are no longer necessary.

[0023] A device according to the invention and a

[0024] Procedures can also be used in conjunction with a tympanometer.

[0025] With regard to an arrangement according to the invention, it is provided that the device is connected to the audiometer via the first interface and / or to the at least one sound transducer via the second interface, wherein the device is in data connection with the operating device via the remote communication device, preferably wherein the data connection is realized via an internet connection.

[0026] A free-field reference microtone can also be used via the second

[0027] Interface., or a separate interface with the

[0028] Audiometer connected.

[0029] The data connection allows both operation and reception of measured values ​​from the device using the

[0030] Operating device possible.

[0031] With regard to a method according to the invention, the following steps are provided:

[0032] Transporting the device for remote calibration of the audiometer and the at least one sound transducer to the location of the audiometer,

[0033] Connecting the device to the audiometer via the first interface and / or to at least one sound transducer via the second interface, operating the device remotely and / or

[0034] Transfer of data determined by the device

[0035] measured values, and

[0036] Calibrating the audiometer based on the determined

[0037] Measured values.

[0038] In the event that the measured values ​​are not transmitted, they can be provided for to be automatically fed into the calibration process.

[0039] Further advantageous embodiments of the invention are defined in the dependent claims.

[0040] According to one embodiment, it can be provided that the device has a free-field calibration device for free-field calibration of the audiometer, wherein the free-field calibration device comprises at least one free-field reference microphone, a support device and a device for positioning the free-field calibration device.

[0041] Free-field calibration refers to the calibration of an audiometer's loudspeaker. This can be done using the free-field reference microphone of the free-field calibration device. The free-field reference microphone must be correctly positioned relative to the loudspeaker, which can be achieved using the support device and the positioning device of the free-field calibration device.

[0042] It can further be provided that the device for positioning the free-field calibration device comprises means for, preferably optically, detecting a position indicator, preferably a ground marking. Thus, the required distance of the

[0043] Free field calibration device for the audiometer can be easily and repeatably found by placing the free field calibration device on the position indicator.

[0044] It is also conceivable that the device for positioning the free-field calibration device can be used to check the correct position of a patient or a chair for the patient who is being audiometrically tested.

[0045] It can also be provided that an optical and / or acoustic signal is emitted when the position indicator is detected, i.e. when the free-field calibration device is correctly positioned.

[0046] Advantageously, it can be provided that the

[0047] Free-field calibration device has a camera, preferably a 360° camera, for capturing an environment of the free-field calibration device.

[0048] It is also conceivable that the camera is designed separately from the free-field calibration device.

[0049] The camera allows the technician to view the area surrounding the free-field calibration device and thus detect interfering objects, such as flowerpots or other decorations. This allows the technician to check whether the free field can penetrate unhindered to the patient or, during calibration, to the free-field reference microphone. The position and orientation of the free-field calibration device's loudspeakers can also be

[0050] Audiometers can be checked.

[0051] With regard to an arrangement, it can be provided that the arrangement has a control device, in particular a computer, for controlling the audiometer, wherein the control device comprises a further remote communication device for remote communication with the operating device.

[0052] In particular, it may be further provided that the

[0053] Control device via the remote communication device in

[0054] Data connection with the operating device, preferably wherein the data connection is realized via an Internet connection.

[0055] It is particularly advantageous if the operating device is designed to operate the audiometer and / or the control device.

[0056] These features, individually or in combination, allow the technician to remotely operate the control device and thus also the audiometer. The technician can thus have the audiometer output the signals they wish to calibrate and then verify them via the device.

[0057] Preferably, it can be provided that the at least one sound transducer is designed as a loudspeaker and / or as an air conduction receiver and / or as an insert receiver and / or as a bone conduction receiver, and / or wherein the audiometer comprises at least one loudspeaker. In particular, if several different sound transducers are provided, a precise diagnosis of the patient's hearing ability can be carried out. With regard to the method, it can be provided that at least one parameter of the at least one sound transducer is determined at a location different from a location of the audiometer before transporting the at least one sound transducer, wherein the determined parameter of the at least one sound transducer is used to calibrate the audiometer.

[0058] To determine at least one parameter of the at least one sound transducer, the at least one sound transducer is coupled to an artificial ear, 6cc coupler of an artificial mastoid, depending on the type of sound transducer, since the at least one sound transducer behaves in a similar way to when it is in contact with human ears or the human skull bone.

[0059] Coupling at least one of the transducers to the artificial ear or mastoid is very challenging and requires considerable practice. Incorrectly coupled transducers can lead to systematic deviations in the calibration process.

[0060] By determining the at least one parameter of the at least one sound transducer before transporting the at least one sound transducer at a location different from the location of the audiometer, for example the location of the calibration service provider, it can be ensured that the coupling and determination of the parameter is carried out by a qualified person, for example the technician of the calibration service provider.

[0061] After transporting the at least one sound transducer, a sound transducer interface of the audiometer, to which the sound transducer can be connected, can be calibrated based on the at least one parameter of the at least one sound transducer. Thus, an entire transducer chain can be calibrated in a traceable manner.

[0062] Advantageously, it can be provided that at least one parameter is a transfer function of the at least one sound transducer.

[0063] However, it is also conceivable that the at least one parameter is a sensitivity, a frequency response, and / or a distortion factor of the sound transducer. In particular, all or various combinations of the aforementioned values ​​can be determined.

[0064] It can further be provided that after the device has been connected to the audiometer and / or the at least one sound transducer, an at least partially, preferably completely, automatic control of the device takes place.

[0065] After the device is connected to the audiometer and / or the at least one sound transducer by a customer, i.e. a layperson, at the location of the audiometer, it can be ensured that the device is correctly connected to the audiometer and / or the at least one sound transducer.

[0066] It is advantageous if this control is completely automated. However, it is also conceivable that it can be partially automated, requiring at least some, if possible minimal, action from the customer.

[0067] Particularly preferably, it can be provided that the measured values ​​determined, preferably electrical and / or acoustic, are output signals of the audiometer.

[0068] The technician can then compare the measured values ​​with reference values, such as the output signals set on the audiometer, and thus monitor the audiometer. Subsequently, the audiometer can be calibrated based on the measured values.

[0069] Further details and benefits of preferred

[0070] Embodiments of the invention are explained in more detail below with reference to the description of the figures and the drawings, in which:

[0071] Fig. 1 is a schematic representation of an arrangement according to the invention,

[0072] Fig. 2 is a flowchart of an on-site method according to the prior art, and

[0073] Fig. 3 is a flow chart of a method according to the invention.

[0074] Figure 1 shows a schematic representation of an arrangement 8 according to the invention. The arrangement comprises an audiometer 2, which has a loudspeaker 2a. Defined tones for diagnosing a patient's hearing can be output via the loudspeaker 2a.

[0075] The Audiometer 2 also includes a

[0076] Transducer interface 2b, to which at least one

[0077] Transducer 3 can be connected. In the present embodiment, two transducers 3 can be connected via the

[0078] Transducer interface 2b is connected to the audiometer 2.

[0079] To calibrate the audiometer 2, a remote calibration device 1 can be connected to the audiometer 2 via a first interface 1a. In particular, the device 1 is connected to the sound transducer interface 2b.

[0080] The device 1 also has a second interface 1b, via which at least one sound transducer 3, in this embodiment two sound transducers 3, can be connected to the device 1. This allows the same conditions to be created for the calibration of the audiometer 2 as those that exist during operation of the audiometer 2 when the sound transducers 3 are connected to the audiometer 2.

[0081] The device 1 further comprises a remote communication device 4, via which a data connection 9 can be established between the device 1 and an operating device 5. A technician can operate the device 1 via the operating device 5. Measured values ​​from the device 1, i.e., measured values ​​measured by the device 1, can also be received by the operating device 5.

[0082] The device 1 further comprises various electronic components, for example, measurement electronics, for controlling and / or calibrating the audiometer 2. These electronic components are already known and will not be explained in detail here. The control device 5 is located at a location different from the location of the audiometer 2. In particular, the control device 5 can be located at a location of a calibration service provider, while the audiometer is located at a location of a customer of the calibration service provider.

[0083] The operating device 5 can be, for example, a computer.

[0084] The audiometer 2 is connected to a control device 10, by means of which the audiometer 2 can be controlled. The control device 10 has a further remote communication device 10a, via which the control device 10 is in data connection 9 with the operating device 5.

[0085] The control device 10 and thus the audiometer 2 can also be operated via the operating device 5.

[0086] In particular, the control device 10 can be designed as a computer.

[0087] It is also conceivable that the control device 10 in the

[0088] Audiometer 2 is integrated.

[0089] The data connections 9 can preferably be made via a

[0090] Internet connection must be realized.

[0091] In this embodiment, a sound transducer 3 is

[0092] Air conduction earpiece and another transducer as

[0093] The transducers 3 can also be designed as insertable earphones and / or loudspeakers. Combinations of different types of transducers 3 are also conceivable.

[0094] In Fig. 1, a free-field calibration device 6 of the device 1 can also be seen.

[0095] Free-field calibration device 6 comprises a free-field reference microphone 6a, which is arranged on a support device 6b. In this embodiment, the support device 6b is designed as a tripod. Of course, other embodiments are also conceivable.

[0096] The free-field reference microphone 6a can be positioned at the correct height using the support device 6b.

[0097] For example, end stops can also be provided to ensure that a permissible height is not exceeded or undercut.

[0098] The free-field calibration device 6 further comprises a

[0099] Device 6c for positioning the free-field calibration device 6. The device 6c for positioning the free-field calibration device 6 has means for, preferably optically, detecting a position indicator 7, preferably a floor marking. Said means can be, for example, a camera, a laser scanner, or the like, which can detect the position indicator 7. In the present exemplary embodiment, the position indicator 7 is designed as a floor marking. This allows the spatial distance between the free-field calibration device 6 and the audiometer 2 to be set correctly and, above all, repeatably. The position of the free-field reference microphone 6a in space is thus clearly determined and reproducible, except for rotation about a vertical axis.

[0100] It can also be provided that the correct positioning of the free-field calibration device 6 above the floor marking 7 is confirmed by visual and / or acoustic signals.

[0101] In addition, confirmation of the correct position can be transmitted via the remote communication device 4 and the data connection 9 to the operating device 5, and thus to the technician.

[0102] In principle, with regard to the free-field calibration device 6, it would also be desirable to align the free-field reference microphone 6a perpendicular to the plane of the loudspeaker membrane. However, this is only possible with considerable effort. It has been shown, however, that the direction of incidence has little influence on the displayed measured value.

[0103] Therefore, a free field incident radially on the free-field reference microphone 6a can be desired. This can be achieved with a free-field calibration device 6 as described above.

[0104] However, a sound incidence angle is of great importance for the displayed measured value and must therefore be corrected. The corresponding correction values ​​for sound incidence angles for the typical frequencies used in audiometry, for example, 125 Hz to 16 kHz, can thus be determined for the corresponding free-field reference microphones 9 before using a free-field calibration device 6.

[0105] Fig. 2 shows a flowchart of an "on-site" procedure according to the state of the art. The "on-site" procedure is named after the fact that the audiometer is checked or calibrated on-site, i.e., at the location of the audiometer. Before the actual calibration of the audiometer can begin, several preparatory steps must be performed.

[0106] In a first step, technical questions are clarified, such as the type and number of audiometers to be calibrated.

[0107] The next step involves planning the route and scheduling a suggested appointment. The first step involves considerable effort, as numerous factors must be considered, such as other customers, available staff, available equipment, etc.

[0108] The proposed appointment can then be presented to the customer, who can then either accept or decline. If the request is rejected, the route planning and the proposed appointment must be redrafted, which involves considerable additional work.

[0109] Once all suggested appointments on a route have been accepted by the relevant customers, the vehicle and equipment can be reserved accordingly and the appointment can be fixed.

[0110] For the appointment, the technician will travel to the customer, i.e. to the location of the audiometer.

[0111] There, the technician documents the condition of the audiometer in advance and then begins calibrating it.

[0112] The calibration includes a free-field calibration, i.e. the calibration of a loudspeaker of the audiometer, as well as a calibration of sound transducers, for example air conduction earphones, insert earphones and / or bone conduction earphones.

[0113] The technician will then also

[0114] Checks and / or a subjective test are carried out, in which external interference, for example noise from electromagnetic fields in the vicinity, is to be checked.

[0115] Finally, the technician documents the condition of the audiometer after calibration before either moving on to the next customer or to a hotel or starting the return journey.

[0116] It is therefore clear that an "on-site" procedure according to the state of the art is quite complex due to the travel times and the associated expenses and, as already described, entails some disadvantages.

[0117] Fig. 3, however, shows a flow diagram of a method according to the invention. In a method according to the invention, analogous to the prior art, in a first

[0118] Step technical questions clarified.

[0119] However, in the next step, an appointment can be scheduled directly and the required resources can be reserved for that date. At the same time, a check of the required measuring devices can be carried out.

[0120] The next five steps, highlighted in grey as shown in Fig. 3, are carried out by the calibration service provider's technician at the calibration service provider's location.

[0121] A parameter, in this case the

[0122] The transfer function of at least one sound transducer 3, or as shown here, several sound transducers 3, is determined. These sound transducers 3 and a device 1 for remote calibration of an audiometer 2 can then be prepared for transport to the location of the audiometer.

[0123] Finally, the device 1 and the transducers

[0124] 3 are packed in special transport containers which, for example, keep the temperature and humidity inside them relatively constant in order to avoid damage to the device 1 and / or the sound transducers 3.

[0125] The device 1 and the sound transducer 3 are then transported on time to the location of the audiometer 2, i.e., to the customer. The following gray-shaded process steps then take place at the location of the audiometer 2, whereby the technician can remotely operate the audiometer 2 and / or the device 1 via the control device 5 at the calibration service provider's location. In the next step, the customer connects the device

[0126] 1 with the audiometer 2 and builds the

[0127] Free field calibration device 6 accordingly.

[0128] This is followed by an essentially automatic control of the

[0129] Device 1, wherein only one hand movement of a customer, for

[0130] Starting the control is necessary It is also conceivable that the control runs completely automatically.

[0131] The free field calibration then takes place, with the technician remotely operating both audiometer 2 and device 1 via the control device 5 in order to perform the free field calibration.

[0132] In a further step, the sound transducers 3 are connected to the device 1. The technician can then remotely transmit offset data or other data to the audiometer 2 and / or the device 1 based on the previously determined parameter of the sound transducers 3, in this case the transfer function.

[0133] The sound transducer interface 1b can then be checked via the device 1. The connected sound transducers 3 serve to ensure the same conditions as during operation of the audiometer 2, when the sound transducers 3 are connected to the audiometer 2.

[0134] Subsequently, the output signals of audiometer 2 are measured and monitored. Noise and electromagnetic interference, which are subjectively monitored by the technician in the on-site procedure, are remotely monitored in the method according to the invention using limit curves in the frequency spectrum. Two-way communication can be monitored by comparing the signal curves of the left and right transducers.

[0135] Finally, the condition of the audiometer 2 is documented after calibration before the device 1 and the old transducers 3 are returned by the customer. A shipping service provider can also be used here.

[0136] Key to the reference numbers:

[0137] 1 Device la first interface.

[0138] 1b second interface

[0139] 2 audiometers

[0140] 2a speakers

[0141] 3 sound transducers

[0142] 4 Remote communication device b Control device

[0143] 6 Free-field calibration device

[0144] 6a Free-field reference microphone

[0145] 6b Support device

[0146] 6c Positioning device

[0147] 6d camera

[0148] 7 Position indicator

[0149] 8 Arrangement

[0150] 9 Data connection

[0151] 10 Control device

[0152] 10a additional remote communication device

Claims

Patent claims 1. Device (1) for remote calibration of an audiometer (2), wherein the device (1) has a first interface (1a) for connecting the device (1) to the audiometer (2) and / or a second interface (1b) for connecting the device (1) to at least one sound transducer (3), characterized in that the device comprises a remote communication device (4) for remote communication with an operating device (5) spatially spaced from the device (1) for operating and / or receiving measured values of the device (1).

2. Device (1) according to claim 1, wherein the device (1) has a free-field calibration device (6) for free-field calibration of the audiometer (1), wherein the free-field calibration device (6) comprises at least one free-field reference microphone (6a), a support device (6b) and a device (6c) for positioning the free-field calibration device (6).

3. Device (1) according to claim 2, wherein the device (6c) for positioning the free-field calibration device (6) comprises means for, preferably optically, detecting a position indicator (7), preferably a ground marking.

4. Device (1) according to one of claims 2 or 3, wherein the free-field calibration device (6) has a camera (6d), preferably a 360° camera, for capturing an environment of the free-field calibration device (6).

5. Arrangement (8) comprising an audiometer (2), at least one sound transducer (3), an operating device (5), in particular a computer, and a device (1) according to one of claims 1 to 4, wherein the device (1) is connected to the audiometer (2) via the first interface (1a) and / or to the at least one sound transducer (3) via the second interface (1b), wherein the device (1) is in data connection (9) with the operating device (5) via the remote communication device (4), preferably wherein the data connection (9) is realized via an Internet connection, 6. Arrangement (8) according to claim 5, wherein the arrangement (8) comprises a control device (10), in particular a computer, for controlling the audiometer (2), wherein the control device (10) comprises a further remote communication device (10a) for remote communication with the operating device (5). Arrangement (8) according to claim 6, wherein the control device (10) is in data connection (9) with the operating device (5) via the remote communication device (10a), preferably wherein the data connection (9) is realized via an Internet connection.

8. Arrangement (8) according to one of claims 5 to 7, wherein the operating device (5) is designed to operate the audiometer (2) and / or the control device (10), 9. Arrangement (8) according to one of claims 5 to 8, wherein the' at least one sound transducer (3) is designed as a loudspeaker and / or* as an air conduction earpiece and / or as an insert earpiece and / or as a bone conduction earpiece, and / or wherein the audiometer (2) comprises at least one loudspeaker (2a), 10. A method for remote calibration of an audiometer (2) by means of a device (1) according to one of claims 1 to 4, characterized by the following steps: Transporting the device (1) for remote calibration of the audiometer (2) and the at least one sound transducer (3) to the location of the audiometer (2), connecting the device (1) to the audiometer (2) via the first interface (1a) and / or to at least one sound transducer (3) via the second interface (1b), operating the device (1) remotely and / or transmitting measured values determined by means of the device (1), and calibrating the audiometer (2) on the basis of the measured values determined.

11. The method according to claim 10, wherein at least one parameter of the at least one sound transducer (3) is measured prior to transporting the at least one sound transducer (3) at a location of the audiometer (2) different location, wherein the determined parameter of the at least one sound transducer (3) is used to calibrate the audiometer (2).

12. The method according to claim 11, wherein the at least one parameter is a transfer function of the at least one switching converter (3).

13. The method according to one of claims 10 to 12, wherein after connecting the device (1) to the audiometer (2) and / or the at least one sound transducer (3), an at least partially, preferably completely, automatic control of the device (1) takes place.

14. The method according to one of claims 10 to 12, wherein the determined measured values, preferably electrical and / or acoustic, are output signals of the audiometer (2).

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