Measuring Sound Detection and Reaction Time in Infant and Toddler Cochlear Implant Recipients Using an Observer-Based Procedure: A First Report
Year: 2009
Type: article
Abstract: In Brief Objectives: First, to establish the feasibility of the observer-based psychophysical procedure (OPP) in measuring sound detection in infant and toddler cochlear implant (CI) recipients. Second, to measure the psychometric function for detection (PFD) from individual subjects. Third, to determine whether reaction time (RT) provides information about the auditory sensitivity of young CI users. Design: Twelve CI recipients, 11 to 32 mo old, participated in our study. Initially, tones were presented in sound field, and children learned to respond when they heard tones but not at other times. Once an 80% correct criterion was met in sound field, a novel stimulation paradigm was used to present stimuli to a single electrode while the child listened to acoustic input on most other electrodes using their usual map. The PFD and RT were measured using this single-electrode stimulation paradigm. Results: Eleven subjects met criterion, 6 within the minimum possible number of trials. For eight subjects, the asymptotic level of detecting single-electrode stimuli averaged 86% correct, similar to levels achieved by normal-hearing infants and toddlers detecting pure tones. The PFD slope of infant and toddler CI recipients was less than or equal to the slope for adult CI users reported in previous studies. RT decreased significantly with stimulus level in four children. Conclusions: These preliminary results suggest that psychophysical detection data can be obtained from infant and toddler CI recipients using OPP. The PFD of young CI users may be shallower than that of adult CI users. Relatively good asymptotic detection performance implies that young CI users are more attentive to sound than has been suggested in previous studies. RT tended to be a less reliable measure of detection, but methodological changes could improve its utility. Psychoacoustic studies of infant and toddler cochlear implant (CI) recipients could contribute to a better understanding of auditory development in this population. In this study, young CI-users' sound-detection ability was assessed using the observer-based psychophysical procedure. Detection accuracy and reaction time were examined. A stimulation method was developed to present single-electrode stimulation with concurrent ambient sound processing on other electrodes. Detection accuracy generally increased, and in some children, reaction time decreased, with increasing stimulus level. Asymptotic detection accuracy was comparable with that reported for normal-hearing children. Psychometric function slopes were comparable or shallower than those reported for adult CI users.
Source: Ear and Hearing
Institutions: University of Washington, Seattle Children's Hospital
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1994669503