Suprathreshold abnormalities of the stapedius reflex in acoustic tumor: a series of case reports.

Suprathreshold morphologic characteristics of the acoustic stapedius reflex are reported for five subjects with acoustic tumor. Results support the hypothesis that changes in suprathreshold morphology may be more sensitive to acoustic tumor than conventional reflex threshold and decay measures. Both the afferent relative amplitude index (AI) and measures of sequential variability of individual waveforms appear to be especially promising.