[The threshold of 1.5 khz as a graduator for the noise induced hearing defect (author's transl)].

Austria's new legislation on the protection of employees and workers provides that the determination and assessment of noise-induced hearing defects caused at the working places may now also be carried out by physicians who are not otologists. Since language-audiometric data are not available to such physicians, the assessments are based only on sound-audiometric hearing results. Therefore, it is understandable that such physicians would like to be able to draw conclusions as to the extent of the noise-induced hearing defect from the sound-audiogram alone. The difficulties encountered in the attempt to determine language-hearing on the basis of sound-hearing are well-known. Among all defects the noise-induced hearing defect is still best suited for such attempts because of its stereo-typical curve in the sound-audiogram. 500 cases with a pure noise-induced hearing defect are subjected to a multiple regression analysis. The result of the investigation confirms the practical observations made. The sound-audiometric hearing loss at 1.5 kHz is closely related to the discrimination capacity for our language and thus gives some indication as to the degree of the noise-induced hearing defect.