Dual-Task Interference in the Assessment of Listening Effort Before and After Cochlear Implantation in Adults: A Longitudinal Study

Purpose: This study aimed to assess the magnitude and direction of dual-task interference in a listening effort dual-task paradigm in individuals with severe-to-profound hearing loss before and in the short- and long-term after cochlear implantation. Design: The study sample consisted of 26 adult candidates for cochlear implantation with severe-to-profound hearing loss. The dual-task paradigm consisted of a primary speech understanding task, conducted in a quiet condition, and a favorable and unfavorable noise condition on the one hand and a secondary visual memory task on the other hand. The dual-task effect for both tasks and the derived patterns of dual-task interference were determined. Participants were evaluated at four test moments: before cochlear implantation and at 3 months, 6 months, and 12 months after implantation. Results: Across all listening conditions, a shift was observed from patterns of dual-task interference with worse and stable scores for the primary speech understanding task in the dual-task condition compared to the baseline condition before implantation, toward patterns in which stable or better scores were obtained, respectively, for the primary task in the dual-task condition after implantation. This indicates that more attention could be allocated to the primary speech understanding task during the dual-task condition after implantation, implying a decreased listening effort. Conclusions: A decreased listening effort was found after cochlear implantation. This study provides additional insights into the evolution of dual-task interference after cochlear implantation. It highlights the importance of interpreting both the primary and secondary tasks using a dual-task paradigm in the assessment of listening effort.