Stapedius Reflex Amplitude and Decay in Normal Hearing Ears

Stapedius reflex data were obtained from 68 patients with normal hearing thresholds and without history of ear disease. The patients were divided into age groups by decade, and the data were studied with respect to reflex threshold, amplitude, and decay.Reflex thresholds were higher in the younger age groups than those observed in the older patients. Amplitude was greatest in the middle age groups and was found to be frequency-dependent (greatest at 2,000 Hz and smallest at 4,000 Hz). Decay of the reflex was measured by determining half-life and the slope of the amplitude decrement during a ten-second stimulation. Decay was found to be greatest at 4,000 Hz and was rarely present at 500 Hz.