[Experiences with high-frequency hearing tests in the selection of personnel for noise occupations]

A total of 181 persons aged between 16 and 18 were checked fully audiometrically (conventional and high-frequency audiogram). Dates of history about hereditary hearing damage, own ear diseases, noise exposure during frequent visits to discothecs or usage of Walkman etc. were ascertained by questionnaires. The evaluation of the results was carried out with the help of discrimination analysis allowing a multi-dimensional classification. As a result there could be made a sure discrimination analytic separation in persons with ear diseases during their childhood, when the high frequencies from 10 to 15 kHz were taken in. Thus the damage of the inner ear was to be found mainly on the base of the cochlea. Also in cases of hereditary influence there was to be seen a clear deminution in the high frequency area. The group of persons, who regularly went to discos (more than three times a month) as well as the group often using Walkman revealed a sure separation, when the high frequencies above 8 kHz were considered in the calculation. Altogether there could be seen an early damage more clearly in the high frequency area after ear diseases in childhood as well as a result of sound overloading than in conventional hearing area.