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Pupil size varies with word listening and response selection difficulty in older adults with hearing loss


  • We thank the study participants. Work was supported in part by a Hearing Health Foundation Centurion Clinical Research Award, the National Institute on Deafness and other Communication Disorders (P50 DC00422), and was conducted in a facility constructed with support from Research Facilities Improvement Program (C06 RR14516) from the National Center for Research Resources, NIH. This project was also supported by the South Carolina Clinical and Translational (SCTR) Institute, with an academic home at the Medical University of South Carolina, NIH/NCRR (UL1 RR029882).

Address correspondence to: Stefanie E. Kuchinsky or Mark A. Eckert, Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, 135 Rutledge Ave., MSC 550, Charleston, SC 29425, USA. E-mail: or


Listening to speech in noise can be exhausting, especially for older adults with impaired hearing. Pupil dilation is thought to track the difficulty associated with listening to speech at various intelligibility levels for young and middle-aged adults. This study examined changes in the pupil response with acoustic and lexical manipulations of difficulty in older adults with hearing loss. Participants identified words at two signal-to-noise ratios (SNRs) among options that could include a similar-sounding lexical competitor. Growth Curve Analyses revealed that the pupil response was affected by an SNR × Lexical competition interaction, such that it was larger and more delayed and sustained in the harder SNR condition, particularly in the presence of lexical competition. Pupillometry detected these effects for correct trials and across reaction times, suggesting it provides additional evidence of task difficulty than behavioral measures alone.