Auditory brain stem response and central auditory test findings for patients with brain stem lesions: A preliminary report

Basic audiologic data, as well as five selected measures of the auditory brain stem response, and results from seven central auditory tests were obtained from ten adult subjects with a variety of brain stem lesions. The ABSR measures included latency, waveform morphology, amplitude ratio, presentation rate and intensity function. The central tests administered were competing sentences, rapidly alternating speech, binaural fusion, staggered spondaic words, dichotic digits, frequency patterns and low pass filtered speech. Both procedures (ABSR and C.A.T. battery) were highly sensitive to brain stem lesions in the study group as a whole, but showed some limitations for individual subjects. The data also indicated the value of employing a test battery and multiple electrophysiologic measures as opposed to single indices of auditory performance. Findings on individual central tests and ABSR measures are reported, as well as data on laterality effects.