Pupillometry Studies of Listening Effort: Implications for Clinical Audiology

Listening can require substantial mental effort, even for those whose hearing thresholds are within normal limits. For individuals with hearing loss, listening-related effort and fatigue can be especially detrimental to their communication and, more broadly, to their quality of life. Without a standard metric of effort, hearing healthcare providers are limited in their ability to quantify these common patient complaints and to track changes in them over time and with intervention. This chapter provides an overview of the factors that impact listening effort, the importance of its quantification from a clinical audiology perspective, and the evidence that an objective physiological response - pupillometry - may be particularly well suited to measure it. Changes in pupil dilation are sensitive to the acoustic, linguistic, and cognitive challenges that occur in real-world listening situations and can reveal individual and group differences that may otherwise go missed using intelligibility scores alone. Pupillometry can furthermore provide insight into how effort unfolds across different timescales, indexing not only engagement in a listening task but also baseline levels of arousal and fatigue. Thus, research suggests a role for pupillometry in enhancing audiology assessments, counseling, and treatments. Ongoing advances in technology have created the possibility for pupil dilation to be recorded inexpensively and unobtrusively during a clinical session. Coupled with an improved understanding of its reliability and sensitivity within patient populations, there is increasing potential for pupillometry to be integrated into audiological batteries, device fittings and configurations, and intervention outcome assessments.