Auditory brainstem responses from human adults and infants: influence of stimulus onset

Auditory brainstem responses were recorded from adults and 3-month-old infants in response to gated noise bursts of variable rise/fall time. Stimuli were presented at 50 dB nHL for rise/fall times of 0, 1, 2.5, and 5 ms. Acoustic spectra of noise-burst stimuli were identical for all rise/fall conditions. Results show that increases in stimulus rise time were accompanied by increased latency and decreased amplitude of ABR wave V recorded from both adult and infant subjects. Constant differences between adult and infant data were observed across rise/fall conditions for both latency and amplitude values. Adult and infant subjects do not differentially process stimulus onset.