Cerebellopontine angle lesions: an audiological test protocol.

Audiological test protocols were devised for use in patients suspected of having a cerebellopontine angle tumor. Data supporting the logic for inclusion of each test are presented. Protocol design was based on test results obtained in 45 tumor and 554 non-tumor patients. In summary, we found: 1) speech-in-noise results were of some value in those patients with normal hearing and of no value in those patients with hearing loss, 2) the acoustic reflex test gave misleading information in 25% of patients, and 3) the ABR test proved to be the most effective test in separating tumor and non-tumor patients. All individuals having cerebellopontine angle tumors and 11% of those without such lesions had abnormal ABR results in this series.