[The validity of various audiometric testing methods in tumor-induced hearing disorders]

In order to study the diagnostic possibilities for detecting acoustic neuromas respectively tumors of the cerebello pontine angle 60 patients with secured tumor (op. confirmed) were preoperatively examined audiologically . The test results were worked out statistically and checked of their validity in respect of the diagnosis. It could be found, that the results of the conventional audiometry, if taken in its entirety, approved a secure diagnosis in most of the cases; though very discretely marked constellations of test results had to be considered. Routine-audiometric failures were essentially restricted to patients which were deaf or had a high-grade hearing loss ( Lehnhardt 1983). The recordings of auditory brain stem responses of them selves showed in all cases a result in the sense of retrocochlear hearing disorder, not only with regard to prolonged absolute latency times of JV/P6 but also of prolonged interpeak latency times between JI and JV. In cases of monaurale deafness, the ERA supplied a secure criterion for a brain stem disorder because of delayed latency times on the not affected side.