title: Effects of stimulus phase on the normal auditory brainstem response.
abstract: The purpose of this investigation was to determine the effects of stimulus phase on the latencies and morphology of the auditory brainstem response (ABR) of normal-hearing subjects. Although click stimuli produced equivalent ABR latencies for the rarefaction and condensation phases, the subtraction of the waveforms from the two phases yielded a difference potential. Tone pip stimuli produced polarity differences that were inversely related to stimulus frequency: the higher the frequency, the smaller the ABR latency differences between responses to rarefaction and condensation stimuli, and the smaller the difference potentials. Thus, whereas the latency of click-evoked ABR is dominated by high-frequency responses with equivalent latencies regardless of stimulus phase, low-frequency responses contribute to the overall morphology of the ABR that yields the phasic difference potential. The implications of these findings are discussed with reference to subjects with high-frequency hearing losses.
authors.affiliation: VA Medical Center, Long Beach, California.
authors.forename: C G
authors.initials: CG
authors.lastname: Fowler
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001300:Audiometry, Evoked Response; D001307:Auditory Perception / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D008297:Male