[Central hearing loss in patients with fronto-basal fractures of the skull (author's transl)].

23 persons were examined with regard to post-traumatic hearing damage after having had a frontobasal injury of the skull. The occurrence of central hearing damages was especially looked for. On the basis of preceding experiences with central hearing test methods gathered on persons with noise-induced hearing damage 21 victims of accidents had to undergo the following three special tests apart from the usual audiometrical procedures: Dichotic discrimination test, acoustic trigger action of the impedance jump and direction audiometry. The investigations had the following results: 1. Damages of the inner ear in the high frequency range originate for the most part also in frontobasal fractures of the skull--basocochlear type. 2. Damages of the inner ear are small and indicate a continuous increase towards higher frequencies. 3. The dichotic discrimination test is positive only in a few cases (4 out of 21). 4. Direction audiometry clearly indicates the existence of central damages (increase of the lateral position angles). 5. With transanimated cases the deviations of central hearing damages equal the average. As a consequence of the studies under consideration a search for central hearing damages after frontobasal fractions of the skull is recommended. In these cases investigation methods of direction audiometry seem to be particularly convincing.