Auditory Findings in Brain Stem Disorders

Abstract

Audiometric tests were administered to 16 patients with intra-axial brain stem lesions. Eight patients showed some audiometric loss in one or both ears. Maximum speech intelligibility (PB) scores were at least 80% in 10 patients. In the remaining, depressed PB maximum performance was found either on both ears or on the ear contralateral to the site of lesion. Performance-intensity (PI) functions for PB words yielded a consistent difference between ears across all intensity levels in nine patients. Performance on synthetic sentence identification (SSI) materials was disporportionately poor for sentences in the presence of ipsilateral competing speech messages (ICM). In the presence of contralateral competing speech messages (CCM), SSI performance generally remained within the normal range. A relatively greater performance deficit for the ICM task than for the CCM task was an important characteristic of brain stem disorder.