ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4aPP2. Effects of repetition rate, phase, and frequency on the auditory brain-stem response in newborn neonates and adults.

T. K. Parthasarathy

Dept. of Speech Pathol. and Audiol., Southern Illinois Univ., Edwardsville, IL 62026

Paul Borgsmiller

Cardinal Glennon Children's Hospital, St. Louis, MO 63104-1095

Barbara Cohlan

St. Mary's Health Ctr., St. Louis, MO 63117

Effects of repetition rate, phase, and frequency on wave V latency of the auditory brain-stem response (ABR) were evaluated and compared in ten normal newborn neonates and adult subjects. Single cycle sinusoids at 0.25 and 2.0 kHz were presented monaurally via an insert earphone at 75 dB nHL, using either a condensation (C) or a rarefaction (R) stimuli at two rates, 11.1 and 55.5/s. The stimulus phase by frequency interaction was significant. In both neonates and adult subjects, the ABR wave V latency for R stimuli was significantly shorter compared to C stimuli at 0.25 kHz. However, the effect of phase on wave V latency was insignificant at 2.0 kHz. Furthermore, the stimulus rate by age interaction was significant. The ABR wave V latency shift with an increase in repetition rate was significantly greater in the newborn neonates than in the adult subjects.