The effects of competing auditory, visual, and combined stimuli on speech perception in normal-hearing and hearing-impaired children
Abstract
This study investigated the effects of competing stimuli on auditory-visual speech perception in normal-hearing and hearing-impaired children. Three types of competing stimuli were utilized: auditory "classroom" noise; visual distractions in the form of videotaped classroom scenes, which were presented to the subjects' peripheral visual fields; and the two competing stimuli combined. Continuous discourse tracking rate was utilized as the dependent measure. This study utilized a multiple baselines across subjects design followed by an alternating treatments design. The visual analyses of the results revealed that 12 of the 16 subjects showed a trend for tracking rate differences during the experimental conditions relative to baseline rates. Only 9 of those subjects displayed the predicted slower tracking rates during competition. The other 3 showed faster tracking rates during the experimental conditions relative to baseline. The remaining 4 subjects showed variable tracking rates such that no clear pattern could be determined relative to baseline. There were no apparent differences among the competing stimulus effects across subjects or within subject groups. The statistical tests applied showed a significant difference in tracking rates as a function of hearing status: normal-hearing subjects had faster mean tracking rates than hearing-impaired subjects. No significant differences in tracking rates were found as a function of gender, experimental conditions, or conditions relative to baseline. The effects from the competing stimuli were not as consistent or as strong as predicted. The literature would suggest, however, that the potential for the visual environment to confound speech perception both by itself and through adverse interactions with the auditory environment remains. The potential confound may be related to attentional effects or more subtle cognitive processing effects. Further research, utilizing alternative visual competitions and speech stimuli and a classroom field study, is warranted.
Degree
Ph.D.
Advisors
Boggess, Purdue University.
Subject Area
Audiology|Speech therapy
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.