Temporal Resolution in Children with Hearing Loss
Marc Brennan, PhD
Hearing loss may reduce access to temporal information. Such a finding would impact service provision for children with hearing loss. However, the impact of childhood hearing loss on temporal resolution and its implications for modifications to service provision are not well understood. The goals of this research were to (1) quantify the effect of auditory experience on the development of temporal resolution in children with hearing loss, (2) and evaluate the extent to which amplification can restore measures of temporal resolution, and (3) explore the impact of temporal resolution and amplification on speech recognition. We obtained forward-masked thresholds, gap-detection thresholds and estimates of speech recognition performance in conditions with and without amplification. Participants included children and adults with hearing loss, and controls groups with normal hearing. We also assessed the relationship between temporal resolution and both hearing-aid use and speech intelligibility. Two hypotheses were tested. The first hypothesis was that children with greater auditory experience show less delay in the development of temporal resolution than children with less experience. The second hypothesis was that audibility and compression speed can be manipulated to improve temporal resolution for CHL.
The findings showed that temporal resolution improved throughout childhood. In general, improvements in temporal resolution with age were similar for the children with and without hearing loss. However, children with hearing loss exhibited deficits in some of the measures. We found that while amplification improved access to temporal cues, this improvement was typically greater in adults than in children with hearing loss. Lastly, speech recognition data were obtained using amplification settings that varied in the extent to which they provided access to temporal cues in speech. Superior speech recognition occurred when using settings that better restored access to temporal cues. This work has provided new knowledge about the impact of childhood hearing loss on temporal resolution and has implications for improving speech recognition with amplification for individuals with hearing loss.
As part of this project, Marc Brennan developed software in collaboration with the Technology Core that generated the stimuli, controlled stimuli playback and recorded participant responses. This computer program has been shared with researchers at the University of Toronto and the National Center for Rehabilitative Researchers. Once data from the studies using these programs have been published, we plan to make this program available for others on the BTNRH website.