Listening effort and fatigue: insights from pupillometry

Individuals with hearing loss commonly report feelings of fatigue and stress as a result of the mental demands of listening in everyday situations. Previous attempts have been made to characterise this phenomena by measuring listening effort objectively. One such objective measure of listening effort is pupillometry. Pupil size is sensitive to changes in attention and memory load, and has been shown to reflect the mental effort required to understand speech in challenging listening environments (Zekveld et al, 2010). Pupil size has also been shown to reflect subjective fatigue (e.g. from sleep deprivation) (Morad et al, 2000). However, it remains unclear whether or not pupil size can characterise listening effort and/or listening-related fatigue in more naturalistic listening tasks.We developed a novel speech-picture verification (SPV) task which involves speech passages being presented with multi-talker babble noise in two different listening conditions (Easy/Hard). Pupil size was recorded using an eyetracker, and the pupil response was analysed over the course of speech processing. Normal-hearing young adults (aged 18-40 years) participated in this study. Findings will be presented along with a discussion of how this data can inform our understanding of listening effort and listening-related fatigue using pupillometric methods.