WO1995011730A1

WO1995011730A1 - Process and device for sensory motion control

Info

Publication number: WO1995011730A1
Application number: PCT/AT1994/000157
Authority: WO
Inventors: Gerhard Roth
Original assignee: Gerhard Roth
Priority date: 1993-10-27
Filing date: 1994-10-27
Publication date: 1995-05-04
Also published as: AU7933294A

Abstract

A process and device for sensory motion control by means of acoustic transmission of information to the controlled person are disclosed. The device is characterised in that a motion sensor (2) that may be secured to the part of the body to be controlled outputs at least one continuous signal to a signal transmission unit during part of the controlled motion. At least one signal flow-dependent signal processing and converting device (3) provided with an acoustic output unit (34) is connected to the sensor (2) and transmission unit by a signal transmission line (230).

Description

Method and device for sensory movement control

The practice of many sports, especially tennis and golf, depends on the movement sequences being carried out as precisely as possible. Practical training shows that movement patterns once learned can only be changed with great difficulty. Video analyzes that are used for these purposes often show movement errors very clearly, but usually do not lead to any real improvement. The reason is likely to be that completely different areas of the brain are responsible for the optical / cognitive processing of image information on the one hand and motor control on the other.

It should be emphasized at this point that an exact and with regard to repeatability and imitability effective checking of movement processes and courses is by no means limited to sport alone. For example, the increase in effectiveness and reduction of fatigue in physically and mentally tiring, repetitive, cyclical work processes, i.e. in the area of ergonomics, recovery of the highest possible mobility after accidents and illnesses, rehabilitation and the like in restoration and accident medicine, should be mentioned as examples. It is of great importance to integrate the test subjects, patients and the like and their senses as much as possible into the training process and its further development over the course of the training period and, if possible, deeper layers of consciousness, perception and control and their feedback to activate with the sensors and receptors on a part of the body to be tested and / or to be watered and to involve it in an interactively progressing training process. This applies not only to self-monitoring by the test person himself, but also to interactive processes between the test person and the trainer.

Ultimately, it is not only the question of training that is essential, it goes without saying that the diagnosis, e.g. in the case of malpositions of joints, limbs, malformations, lesions and movement impairments, possibly also with a psychological background, can benefit from particularly effective but simple methods of recognizing and in particular recognizing a movement sequence by the doctor and patient.

The invention has set itself the task, for the first time, on-genetically secured (feedback) couplings or coupling mechanisms, such as those of hand / arm movement - speaking - listening, for a very substantial improvement in the control of movement sequences in At this point it should not go unmentioned that a number of acoustically operating devices and methods for supporting training processes have become known. With them, however, there is no real accompanying influence on the test subject continuously during a movement sequence to be controlled and corrected, but rather an acoustic alarm is only triggered if a deviation from an "ideal, optimal or standard movement sequence" occurs.

With this type of control, there is on the one hand a psychologically unfavorable, demotivating "punishment effect" when leaving the "correct" movement path and course, on the other hand there are no possibilities for test persons and trainers, even very shortly before an alarm sounds to recognize an incipient, slight, still correctable deviation early and so the above to escape "acoustic punishment".

To avoid these disadvantages of previously known and in use training systems with acoustic warning or the like and a psychologically much more positive and, above all, highly motivational, accompanying guidance of a body part moved by the test person, e.g. To achieve arm, hand, leg or the like, over the duration of a movement cycle and the like with the subconsciously automatically resulting, likewise sliding correction measures, is the primary object of the present invention.

The invention thus relates to a new method for sensor-based control or self-control of movement sequences, preferably for training and / or diagnostic purposes, in particular in the fields of sport, ergonomics, medicine and rehabilitation, with information from the subject, trainer and / or Diagnostic and the like takes place acoustically, the essential features of which are that for accompanying and / or comparative control of at least one, preferably only one, part of the body to be controlled with respect to its movement, preferably extremity, in particular at least one to a high degree or Optimal at the position of the signal level and / or density that is relevant for a movement sequence to be tested, practiced, repeated and / or correcting - position-fixed, but releasably bound, movement sequence sensor that carries out the movement in detail, preferably acceleration, speed Activity and / or location or location change sensor, over at least a partial section, preferably over the total area or the total duration, of a movement sequence or cycle, signals and signal sequences continuously conforming to the movement sequence are generated, and via a, preferably immaterial, transmission path to at least one signal Receive, convert, process, store, and / or output device within which the signals or signal sequences arriving from the sensor are practical, preferably in real time, with the current movement sequence or cycle Synchronous, practically distortion-free imaging, via at least one acoustic reproduction unit, in particular headphones, loudspeakers or the like, in each case continuously emitted and brought to the test subject, trainer, diagnostician or the like, lying in the frequency range, preferably pitch-modulated, acoustic signals or signal frequencies converted become.

The invention therefore provides for the first time a method for sensory movement control, with a sensor - primarily an accelerometer - which is connected to that part of the body which performs the movement to be controlled in such a way that it follows this movement exactly, e.g. in the manner of a wristwatch for golf or tennis, the signals being fed to a signal processing and processing unit, which can be formed by an analog or digital computer, and an acoustic output unit, which generates a tone in real time, the pitch of which corresponds exactly to the respective movement parameter. Each movement pattern thus corresponds to a very characteristic melody that is noticeable at least after repeated repetition, possibly even comprehensible and, which is essential, with a standard melody of an optimal movement sequence, e.g. from memory, is comparable. In-depth observations have shown that even "unmusical" test subjects and trainers can easily distinguish the "correct" movement melody from a "melody of their own movement" that needs to be improved after a short listening-in and practice period, since here the pitch itself, but the tone sequences play the essential role.

Because of the possibility, given for the first time, of the entire movement sequence to be practiced, to be imitated as a "melody continuum", in which delays as pitch and possibly volume reductions and acceleration processes in the movement sequence as acceleration dependent increases in pitch or volume occur, being able to hear, leads to approx. even slight deviations in calibration and can be corrected directly under cortex taxation, to faster training successes than the previously known methods in this sector.

The comparison of the acoustic reproduction of the own movement to be tested and optimized that is produced in the training and the norm (standard) pitch sequence pattern of an optimal movement sequence to be imitated can be carried out in various ways for the method. The simplest is e.g. to have the trainer perform the ideal movement several times and to make the test person hear the melodies of this movement generated at the same time. A further variant consists in "copying" several identical movement sequences and to make the subject hear an "average melody" obtained by averaging or the like, according to which he can correctively correct his current movement.

It has been shown that pitch-coded acoustic reproduction is capable of delivering better training results than volume modulation. A combination of these two modulations is preferred.

With regard to the technique of mostly iterative "playing" the "right" movement sequence melody and its imitation with increasing perfection, there are no limits per se.

Thus, in the case of simple equipment, it is preferred to carry out the training method according to claim 2, which involves a sequential comparison of "optimal melody" and the hearing pattern of a current movement sequence, e.g. Of tennis, gold or the like.

A signal memory is used which can store characteristic movement melodies that can be "played" for comparison when the self-movement melody is called up.

Another variant according to claim 3 provides for a simultaneous reproduction of the optimal melody and the current melody of the test subject, a deviation from the optimal movement sequence also being perceived immediately as a kind of detuning or the like and immediately leading to a first correction of one's own movement.

A further, somewhat more complex, but subjectivity of the hearing impression with current movement with movement pattern reproduction and synchronous optimal pattern reproduction, which rather eliminates An advantageous embodiment of the method according to the invention is covered by claim 4. Instead of the actual movement pattern, the deviation from a movement pattern that has already been stored and is recognized as optimal is output.

Making higher demands on hearing and getting used to it, but also providing multivariate information regarding the movement and its control, is a method variant according to claim 5, wherein depending on the training goal, different arrangements of the intended plurality of sensors, as indicated therein, are possible. So e.g. a second motion-relevant sensor is attached, the output signal, e.g. in a kind of stereophonic listening to the test subject. The playback technique of synchronous playback of two current movement patterns is in principle similar to that used according to claim 3.

In an analogous application of the technology according to claim 4, the multi-sensor method works in the variant according to claim 6.

In order to complete the observation of the movement sequence even further or to analyze errors in the movement to be trained, incorrect postures and the like in combination with the movement sequence melody, it is advantageous to design and supplement the new training method according to claim 7.

If a method based on capacitive sensor technology is used, as provided in accordance with claim 8, there is the advantage that the capacitance of the sensor, which changes as a function of the acceleration, can itself be an integral part of a frequency generator in a signal processing unit which accelerates the signal supplied to it dependent signals converted into speed signals and eg outputs to a transmitter unit to the signal processing device.

A particularly small hindrance to the freedom of movement of the subject during controlled training can be achieved with an embodiment of the new method according to claim 9.

Adjusting the pitches of the motion-mapping melody within the frequency range mentioned in claim 10 also contributes in particular to less tiring training conditions.

Another essential object of the invention is a device or a device for a sensory control or self-control of movement sequences, preferably for training and / or diagnostic purposes, in particular in the fields of sports, ergonomics, medicine and rehabilitation, the test subject, trainer and / or diagnostician and the like are informed acoustically, the use of which has proven particularly effective in the new training method described above. This feature is essentially characterized by at least one - in one with the body part to be checked with regard to its movement, in particular at a high degree or optimum level of movement which is relevant for a movement sequence to be checked, practiced, repeated and / or corrected Signal height and / or density ensuring point of the same - fixed in position, but detachable, connectableπ, preferably arranged in the manner of a wristwatch, attachable housing or the like - movement sequence sensor, in particular acceleration, speed and / or spatial position sensor, with at least one Part of the movement sequence, in particular over an entire movement sequence or cycle, continuous-time signal delivery to a signal transmission unit, preferably also arranged in the housing, and at least one connected to the sensor and transmission unit via a, preferably immaterial, signal transmission path, preferably at least one signal processing and conversion device having a memory unit with an acoustic output unit.

A training device according to claim 12 advantageously enables a direct - comparative comparison of the optimal movement sequence and the current movement of the subject.

In a simple, robust embodiment, such a device advantageously has a loudspeaker as the acoustic output unit.

The acoustic load on the training environment is particularly effectively reduced in a device according to claim 14.

From a sporting point of view, real, practical configurations of the configuration, infrastructure and data transmission used are favorable, as are covered by claims 15 and 16.

Different types and basic principles of technical realizations of sensor-signal transmitter combinations and signal processing devices as well as the above-mentioned, different types of training processes with sequential, time-synchronous and real difference comparison, depending on the task and comfort, the devices according to claims 17 to 21 are particularly suitable .

A direct movement-related sensor system can be effected by using the Doppler effect, with an advantageous embodiment. form of the device, which essentially provides a combination of a current or standard movement of a detailed ultrasound transmitter and a stationary ultrasound receiver as a sensor, all of the aforementioned methods being able to be used in their real use.

It advantageously has the essential components covered by claims 22 to 24.

The invention is explained in more detail with reference to the drawing:

1 shows a diagram of the real arrangement of the components of the new training-supporting devices, FIG. 2 shows a basic diagram or circuit diagram to illustrate the basic function of the new training system in general, FIGS. 3 to 7 Schemes of claims 17 to 21 corresponding different configurations of the new devices and the Fig. 8 to 10 schemes of the double effect in the ultrasound range using device embodiments according to the invention.

Fig.l shows a tennis player as a subject 1, who is performing a backhand stroke with the racket 11 with his right arm 10. At a point 1 which is particularly relevant for the striking movement because of the large differences in acceleration and deceleration, namely on the arm joint 101 or a point just above it, a movement sensor 2 is releasably attached to a joint band 202, similar to a wristwatch. e.g. an accelerometer, arranged in a protective housing 201. The sensor 2, e.g. Signals emitted over an entire impact cycle or a particularly characteristic part thereof pass through an - here intangible signal transmission path 230, e.g. via radio, infrared or the like, into the signal processing device 3, which is located in a housing 301, is also detachably connected to the subject 1 by means of a waist belt 302. Within the device 3, the signals supplied by the sensor 2 are converted into an acoustic signal sequence in the frequency range of the human ear, which is transmitted by an acoustic reproduction unit, e.g. a small loudspeaker 34, which is also located here in or on the housing 301 of the signal processing device 3.

Arranged with arrows in FIG. 1, as in an information loop that ultimately closes, is a continuous sequence of acoustic signals, which, for example, represents a very characteristic “movement melody” corresponding to the beat movement currently being executed, via the ear 102 in Brain or cortex and from there - perceived deviations from the melody of a Standard movement accordingly - correcting the muscle and movement receptors.

The principle diagram of the figure shows schematically the essential components of the new training method.

In a motion sensor 2, signals are generated and converted into a signal capable of transmission. By means of signal transmission 230 ', the transmitted signal after it has been received reaches the signal processing unit 3 and first in its signal processing unit 31 J, where it is converted into an internally processable signal sequence, further reaches the signal evaluation 32', where e.g. averaging of the signal sequences, smoothing, wobbling or the like. he follows. The signal evaluation 32 'is connected to a signal storage 35', in which e.g. Signal sequences of an ideal movement can be stored as "sample templates" and retrieved from them if required.

The evaluation 32 'equipped in this way transmits its internal signals or signal sequences to an acoustic output unit 33' and these are converted into pitch and / or volume pattern in acoustic form in the range of the hearing frequency, e.g. output via a loudspeaker 34 '.

Advantageously, the device, which suitably corresponds to the usual telecommunications conditions, works with voltage sources of 3 V, which contributes significantly to the high flexibility of use and also minimizes any uncomfortable weight loads on the test subject.

3 shows how, from the motion-induced accelerometer 2, an acceleration-proportional, analog output voltage signal sequence via a radio link 230 or the like reaches an integrator 311 within a signal processing device 3, where the voltage is converted into a speed-proportional voltage sequence and in the voltage-frequency converter 331 is converted into an audio frequency signal sequence output to the loudspeaker 34.

FIG. 4 shows a device which is quite similar in its basic concept to FIG. 3, the accelerometer 2 outputting an output frequency proportional to acceleration.

5 operates analog-digital using an accelerometer 2, the output frequency of which is proportional to the acceleration values within a movement sequence to be controlled. The frequency signals pass via the transmission link 230 to a discriminator 312 of a signal processing device 3, from there to Digitization in an up / down counter unit 313 or a down counter 314, and are output as a hearing frequency signal sequence via the loudspeaker 34.

The device according to FIG. 6 is configured in a manner similar to that according to FIG. 3, but has an analog / digital converter 315 processing the signal sequence of the sensor 2 and a memory unit 35 for recording and storing characteristic movement melodies. The central evaluation and processing unit 3 here is a software-controlled microprocessor 316 that can be adapted extremely flexibly to the respective training requirements.

Furthermore, the device according to FIG. 7, configured similarly to the device according to FIG. 6, has a sensor 2 which emits frequency signals proportional to acceleration to a counter 317 for digitization, to which a microprocessor 316 with memory 35 and the loudspeaker unit 34 are again excluded.

For FIG. 8, which specifically shows a golfer 1 and the device training him, the following is explained:

When a discount is carried out, there is a relative movement of the sensor (2) with an ultrasonic transmitter 20 over the distance 2300, which is, for example, 5 m, to the microphone 30. This movement, which is carried out at the speed v (t), generates accordingly Double effect on the microphone 30 a frequency shift .DELTA.f = fc- • ^v (t) / c, where f- the rest frequency and c mean the speed of sound. After passing through a bandpass amplifier 329 with an FM demodulator 330, this frequency shift is converted into an analog voltage, which in turn is converted via a VF converter 331 into a movement-compliant melody output via the acoustic reproduction unit 34.

FIG. 9 shows an arrangement configured similarly to FIG. 8, but using a mixer 335 of an oscillator 337, e.g. with fr, = 1kHz, and a low-pass filter 336, with which the Dopplerv εrschiebuπg is transformed directly into the audible range of 1kHz = Λf. The non-explained reference symbols have the same meaning as in the previous figures.

10 shows an arrangement configured similarly to FIG. 9, but using a counter 313 downstream of the bandpass amplifier 329 as a frequency discriminator with a microcomputer (CPU) 316 and a data memory 35. The signals coming from the bandpass amplifier 329 pass through the counter 313 into the CPU 316, from where they are output again to the playback unit 34 as a movement-conforming melody after corresponding processing. The reference symbols, which are not explained in greater detail, have the same meanings as in the previous figures.

Claims

P ate nt claims:

1. Method for sensoπscnen control or self-control of motion sequences, preferably for training and / or diagnostic purposes, in particular in the areas of sports, ergonomics, medicine and rehabilitation, with information of the subject, trainer and / or diagnostician and the like takes place acoustically, characterized in that for accompanying and / or comparative control of at least one, preferably only one, part of the body to be controlled with regard to its movement, preferably extremity, in particular at least one, a high degree or optimum of a point to be checked, practiced, repeated and / or correcting the relevant signal level and / or density to ensure that the position is the same - positionally fixed but releasably bound, the movement-sequence sensor, which is true to the details of the movement, preferably acceleration, speed and / or spatial position or . Sensor, generated over at least a partial section, preferably over the entire area or total duration, of a movement sequence or cycle of continuously movement-compliant signals or signal sequences and via a, preferably immaterial, transmission path to at least one signal reception, conversion, Processing, processing, storage and / or output device are emitted, within which the signals or signal sequences arriving from the sensor, preferably in real time, are practically synchronous with the current movement sequence or cycle and represent the same practically without distortion. Via at least one acoustic reproduction unit, in particular headphones, loudspeakers or the like, in each case continuously emitted and brought to the test subject, trainer, diagnostician or the like, which are in the hearing frequency range, preferably pitch-modulated, acoustic signals or signal frequencies are converted.

2. The method according to claim 1, characterized in that in the context of an optimal or optimized, standardized, standardized or similar movement sequence generated or, in particular as a means, derived from a plurality of such movement sequences or cycles signal sequences in a memory unit of signal reception -, -Processing and / or playback device are introduced and read in and retrieved for a comparative control at a desired time, in particular just before and / or after a movement sequence or cycle to be checked, possibly repeating and are output via the acoustic repeating device as an acoustic master of the movement sequence.

3. The method according to claim 1 or 2, characterized in that within the framework of an optimal or optimized, standardized, standardized or similar movement sequence generated or, in particular as a means derived from a plurality of such movement sequences or cycles Signal¬ sequences in a memory unit Signal receiving, processing and / or reproducing device are introduced or read in and the pattern is output from there via the acoustic reproduction unit together with an acoustic pattern currently obtained from a movement sequence or cycle of the test person to be checked .

4. The method according to any one of claims 1-3, characterized in that in the context of an optimal or optimized, normalized, standardized or similar movement sequence generated or, in particular as a means, derived from a plurality of such movement sequences or cycles signal sequences in a storage unit the signal receiving, processing and / or reproducing device are introduced or read in, the patterns of which are subjected to a time difference or the like continuously synchronized with the signals or signal sequences or patterns of a current movement sequence to be checked in the signal processing device, and that the respective difference signal sequence pattern generated in this case, preferably after raising in a frequency range of 500-2,500 s, is output as an acoustic difference movement pattern via the acoustic reproduction unit.

5. The method according to any one of claims 1 to 4, characterized in that of two parts of a body part to be checked or of two different body parts of the subject or of two analog body part locations or body parts bound by the subject and trainer, Preferably, functionally and characteristic-identical, motion sensors generated synchronously. Signals or signal sequences processed and synchronously output as acoustic motion patterns to at least one multi-channel and in particular two-channel playback unit, in particular to at least one stereo headphone or the like.

6. The method according to any one of claims 1 to 5, characterized in that of two parts of a body part to be checked or of two different body parts of the subject or of two analog body part locations or body parts bound by subject and trainer, preferably functionally identical and characteristic, motion sensors synchronously generated signals or signal sequences to form a difference signal sequence pattern

1 processed and, preferably after being raised to a frequency range of 500-2,500 s acoustic difference signal sequence pattern are output via the acoustic playback device.

7. The method according to any one of claims 1 to 6, characterized in that the recording and reproduction of the sequence of movements as an acoustic Be¬ movement pattern or the like with Viedoaufnähme and reproductions. the movement to be controlled is combined.

8. The method according to any one of claims 1 to 7, characterized in that an accelerometer or the like, in particular based on at least one capacitance sensor, functions as the motion sensor. is used.

9. The method according to any one of claims 1 to 8, characterized in that an acoustic playback unit, in particular headphones or the like. Ein¬ is used, which is locally separated from the signal processing device or its housing, but sigπally connected to the same via an intangible transmission path is.

10. The method according to any one of claims 1 to 9, characterized in that the acoustic movement pattern or - tone sequences in the hearing frequency range, in particular in the range from 500 to 3,500 s, are emitted by the acoustic reproduction unit.

11. Device or device for a sensory control or self-control of movement sequences, preferably for training and / or diagnostic purposes, in particular in the fields of sports, ergonomics, medicine and rehabilitation, with information of the subject, trainer and / or diagnostician and the like takes place acoustically, in particular to carry out the method according to one of claims 1 to 10, characterized by at least one - in one with the body part to be tested with regard to its movement, in particular at a high degree or optimum for each one to be tested , practicing, repeating and / or correcting the movement sequence of the relevant signal level and / or density ensuring the position thereof - fixed in position, but releasable, connectable, preferably in the manner of a wristwatch, attachable housing (201) or the like. arranged - movement sequence sensor (2), in particular acceleration, speed and / or position sensor, with at least over a partial section of the movement sequence, in particular over an entire movement sequence or cycle, time-continuous signal output to one, preferably likewise in the housing (201), signal processing unit, and at least one signal processing and conversion device with sensor (2) and transmission unit via a, preferably immaterial, signal transmission path (230) signal flow-connected, preferably having at least one memory unit (35). device (3) with acoustic output unit (34).

12. The device according to claim 11, characterized in that the signal processing and conversion device (3) at least one Signal¬ receiving unit, a signal conditioning unit (31 ') and at least one with a signal storage unit (35') connected evaluation unit (32 ') , preferably a signal (sequence) comparator, a differential element or the like.

13. Device according to claim ^' : 11 or 12, characterized in that it has at least one loudspeaker as an acoustic output unit (34', 34).

14. Device according to one of claims 1 to 13, characterized gekenn¬ characterized in that it has as an acoustic output unit (34'34) at least one earphone, preferably stereo headphones.

15. The device according to claim 13 or 14, characterized in that the acoustic output unit (34), in particular headphones or speakers, spatially separated from the signal processing and conversion device (3), but with the same via a, preferably intangible, Signal transmission path is arranged connected to the signal flow.

16. Device according to one of claims 1 to 15, characterized gekennzeich¬ net that the signal processing and conversion device (3) in a on a, preferably around the body center of the subject (1), attachable belt (302) od. the like arranged housing (301) or the like., is arranged.

17. Device according to one of claims 1 to 16, characterized gekennzeich¬ net that it has as the motion sequence sensor (2) has an accelerometer, the output signal, in particular output voltage, the acceleration values within a motion sequence or cycle is proportional to which sensor (2) is connected via a transmission link (230) to an integrating unit (311), which in turn - supplying the same signals corresponding to the speed within the movement sequence, in particular voltage signals - with a tension-frequency converter (331) is connected, which in turn, emitting the signals which it converts into the hearing frequency, is connected to the acoustic reproduction unit (34).

18. Device according to claim 17, characterized in that it has an accelerometer with an essentially unchanged configuration of the other components as the motion sequence sensor (2), the output frequency of which is proportional to the acceleration values within a motion sequence to be controlled.

19. Device according to one of claims 1 to 16, characterized gekennzeich¬ net that it has an accelerometer as the motion sequence sensor (2), Its output frequency is proportional to the acceleration values within a movement sequence to be controlled, and which is connected via a signal transmission path (230) to a discriminator unit (312), from which the signals to an up / down counting unit (313) are connected down with it via corresponding lines - Counting unit (314) to which the latter an acoustic playback unit (34) is connected.

20. Device according to one of claims 1 to 16, characterized gekenn¬ characterized in that it has an accelerometer as the movement sequence sensor (2), the output signal, in particular output voltage, the acceleration values within a movement sequence or cycle is proportional, which sensor (2 ) is connected via a transmission link (230) to an analog-digital converter (315), which in turn is connected to a software-controlled microprocessor unit (CPU) (316) for signal integration and output frequency generation with the memory unit ( 35) for movement sequence signal sequences, from which microprocessor unit (316) the acoustic reproduction unit (34) is controlled.

21. Device according to claim 20, characterized in that it has an otherwise unchanged configuration of the microprocessor unit (316), its memory unit (35) and acoustic reproduction unit (34) as movement sequence sensor (2) has an accelerometer whose output frequency is the same as in this claim Acceleration values within a movement sequence to be controlled is proportional to which sensor (2) is signal-transmission-connected to a counting unit (317) connected to the microprocessor (316).

22. Device according to one of claims 11 to 15, characterized gekenn¬, that it as a motion sensor (2) use a Doppler effect de, via an intangible transmission link (2300) connected combination of ultrasonic transmitter unit (20) and ultrasonic receiver unit ( 30), in particular a microphone, the latter being connected to an acoustic reproduction device (34) via a fire pass amplifier (329), FM demodulator (330) and voltage-frequency converter (331).

23. Device according to claim 22, characterized in that the Ultaschalle pfangseinheit (30) via the bandpass amplifier (329), one of an oscillator (337) with a standard frequency supplyable Mischein¬ device (335) is connected, which in turn via a low-pass filter unit direction (336) is connected to the acoustic reproduction unit (34).

24. A device according to claim 22 or 23, characterized in that the ultrasound receiving unit (30) via the bandpass amplifier (329), a counter (313) and a processor coupled to a memory device (35) the microprocessor (316) having output means with the akusti _¬ rule reproducing unit (34) is connected.