Changes in Listening Effort Through Pupil Response After Atresioplasty in Children With Congenital Aural Atresia

Abstract

Objectives: This study aimed to determine whether the improvement of hearing by surgical treatment alleviates cognitive demands through pupil response in patients with unilateral congenital aural atresia (CAA). Design: A prospective study was performed on patients with unilateral CAA who were scheduled to undergo primary atresioplasty between November 2017 and May 2020. Pure-tone audiometry, auditory digit span test, Korean Speech Perception in Noise test, pupil measurement during speech tests, and questionnaires (Sound-Spatial-Qualities of Hearing Scale; subjective listening effort rating) were performed before and 6 months after surgery. Results: Of 30 consecutive patients who initially enrolled, only 18 patients (12 males and 6 females) were included in the analysis. When the improvement of the air-bone gap and interaural difference of air conduction within 30 dB was defined as a successful hearing outcome, successful hearing improvement was achieved in 50% of the 18 patients. In pupil measurement, the success group had a significantly smaller mean pupil dilation response than the nonsuccess group at 0 and −3 dB signal to noise ratio (SNR) (all p < 0.01). In addition, significant differences were identified between the two groups for peak dilation and peak latency at all noise levels (all p < 0.01). When analyzing the change in pupil response before and after surgery, the difference in relative mean pupil dilation in the success group was significantly greater than that in the nonsuccess group at −3 dB SNR (p = 0.02). In addition, the success group showed a significantly greater change in peak latency than the nonsuccess group at the −3 dB SNR (p < 0.01). The difference in peak dilation tended to be greater in the success group than in the nonsuccess group, but the difference was not statistically significant. Conclusions: Patients with unilateral CAA who achieved surgically improved hearing had a smaller pupil dilation response than those who did not. These results suggest that successful hearing outcomes after surgery in patients with unilateral CAA may reduce the cognitive effort required to understand speech under difficult listening conditions.