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The music habits of 569 pre-teens and teenagers, between 10 and 17 years of age, were examined and exposure to music from portable music players was compared to that in discotheques. Using a questionnaire we determined the length of time spent listening to portable music players and the frequency of disco visits. The individual level of the music heard through portable music players was measured as a free-field corrected short term mean level. The total music exposure (related to 40 hours per week) was calculated from the data and different assumed disco sound levels. We estimated the risk of ear damage according to ISO 1999 standards on the basis of the total music exposure, whereby the mean disco level was varied as a parameter in the range of 95 to 110 dB(A). Taking only the portable music players into account, one can expect that even after 5 years of music, approximately 5% of the total group would have a hearing loss of 20 dB. This percentage clearly rises when additional exposure is given in discotheques having music levels above 100 dB(A). We suggest therefore that for safety reasons the following sound levels should be observed: 90 dB(A) for portable music players and 95 dB(A) for discos. Through adherence to these levels we would expect that 1% of the young people in our study would have a hearing loss > 10 dB, whereas momentary exposure would result in a hearing loss > 10 dB of 10-20%. Therefore we believe that sound level limitations should be enacted immediately for portable music players and in discotheques.

An analysis by means of electronic data-processing is necessary at audiometric surveys because of the great number of audiometric values. To clear off the dates of the audiometric curves is long-winded and therefore expensive. That's the reason why we developed an operating system which allows to store on recording tape the dates of the Hearing Threshold Level and some extra informations about the test person immediately at the survey. The Hearing Threshold has to be appointed in a manner which is usually practiced in the clinic. We have described the setup of the unit and the graphic representation of the audiometric curves by means of a XY-recorder. The system has proved to be a success at the survey of 1,300 employees working in noisy areas. The analysis of the Hearing Threshold Levels could take place immediately after the investigation.

Studies regarding to the continuous registration of the heart frequency by a transportable instrument, which can store the data of the heart frequency per minute up to 24h, are presented. It is a tape recorder the speed of which is geared down. Thus a normal tape cassette C 60 is sufficient for a registration of the heart frequency during 2 X 24h. The R-wave of the ECG is registered on the first channel of the tape as a biological signal. Moreover every minute an impulse of a clock is recorded on the second channel of the tape. With help of a second instrument the play back procedure for the 24-h-recording can be performed in about 15 min. The signals of both channels of the tape are transformed in digital rectangle impulses by an installed impulse-converter. The serial impulses are counted per minute with help of the time-mark by an interface in a counter. These data are at disposal in BCD-code. They can be passed on the following peripherals: digital printer, computer, pen-recorder and so on. A parallel standardized recording of the physical activity observed by the subject or by an experimenter allows a statistical evaluation and comparison of the physical activity with the corresponding heart frequency data. Some examples of the aread of occupational health, epidemiology and exercise physiology are discussed.

Descriptions of each test-panel were read individually to 50 visually handicapped children and their results compared with those of 20 normally sighted. This new method is open for improvement but has already proved to be a useful addition to general clinical examination. In addition to an exemplary description of test-panels number 5 and 15, the projective effect of the visual handicap is shown in the individual topics.

It is demonstrated that physical disabilities involving motor deficits automatically result in communicative limitations which become particularly evident in calsses. As a rule, the consequences of a slow writing performance due to physical disability are a decrease in performance. The supply of intellectually normal but severely physically handicapped pupils with adequate technical aids designed to compensate for their disabilities is, therefore, a necessity which improves their educational opportunities. With the help of an adjusted and technically supplemented tape recorder it is demonstrated in how far a technical apparatus can become the "tool" of a special education teacher.