The auditory brainstem response (ABR) is an evoked potential that has achieved widespread acceptance as a technique for evaluating the status and function of the auditory nervous system. For many diagnostic applications, the latency of an obtained ABR peak is compared to clinical norms. One who uses this approach makes some basic assumptions regarding between-subject and within-subject variability of latency. Although a great deal is known about between-subject variability of ABR latency, virtually nothing is known about such variability within a single subject. The purpose of this investigation was to describe the nature of within-subject variability of ABR latency. Nine male subjects participated in the study. Each met the following criteria: 10-12 years of age; normal speech and language development; normal academic progress; normal hearing; and, normal middle ear pressure. A repeated measures design was employed. Four sessions were scheduled for each subject and five ABRs were obtained at each session for each of three stimulus conditions: monaural left, monaural right, and binaural. Stimuli were 100 μs condensation clicks presented at 80 dB nHL. For each ABR peak, the within-subject distribution of latencies was analyzed with regard to symmetry, kurtosis, range, and standard deviation using the SPSSx "Descriptives" procedure. For every subject, variability of latency was observed. Most often, the latencies were normally distributed and the magnitude of variability was small. The variability of latency, as indexed by the standard deviation, was less within any single subject than is commonly reported for groups of subjects. It was concluded that: (a) standard parametric techniques would be appropriate for subsequent analysis of such data; and, (b) by establishing a baseline, the sensitivity of the ABR might be increased for certain within-subject monitoring applications.

Thesis--M. Phil., University of Hong Kong, 1985.

Thesis (M.S.)--University of Wisconsin--Madison, 1985. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 27-29).

Thesis (M.S.)--Brigham Young University. Dept. of Physiology and Developmental Biology, 2007. / Includes bibliographical references (p. 42-47).

Thesis (Ph.D.)--McMaster University, 2003. / Advisor: Larry E. Roberts. Includes bibliographical references. Also available via World Wide Web.

Thesis (Ph. D.)--University of California, San Diego, 2001. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.

Not available / text

published_or_final_version / Physiology / Master / Master of Philosophy

When a formant transition (isolated transition) and the remainder (base) of a synthesized syllable are presented to opposite ears most subjects perceive two simultaneous sounds, a syllable and a nonspeech chirp. The isolated transition determines the identity of the syllable at one ear and, at the same time, is perceived as a chirp at the opposite ear. This phenomenon, called duplex perception, has been interpreted as the result of the independent operation of two perceptual modes, the phonetic and the auditory mode. In order to test this hypothesis, the isolated transition was preceded and followed by a series of identical transitions sent to the same ear. This streaming procedure weakened the contribution of the transition to the perceived phonetic identity of the syllable. This weakening effect could have been explained in terms of the habituation of an hypothetical phonetic feature detector sensitive to the repetition of identical transitions. For this reason, the same effect was replicated by capturing the isolated transition with others which were aligned on the same frequency-by-time trajectory as the isolated one. These findings are consistent with the idea that the integration of the transition with the base was affected by the operation of general-purpose auditory processes. This contrasts with the hypothesis that the phonetic mode integrated the dichotic stimuli independently of the auditory mode.