Can resting electroencephalography index the development of listening-related fatigue?

Sustained exertion of listening effort by people with hearing loss in order to recognize speech is thought to lead to mental fatigue. Listening-related fatigue has been measured primarily with self-reports. The current study tests the hypothesis that an objective neural measure of increased post-task power of alpha (8-12 Hz) and theta (4-8 Hz) neural rhythms from the resting electroencephalogram (EEG) can index the development of listening-related fatigue. Before and after a challenging listening task, 2 min of eyes-closed and eyes-open resting EEG and self-reports of fatigue on a visual-analogue scale were collected from older adults (n = 28) with age-appropriate hearing (pure-tone average hearing loss from 1, 2, and 4 kHz M = 31.94, SD = 16.74). A numerical trend for the expected post-task increase in power was observed for all EEG measures. However, the difference was significant only for the alpha-band measures. Self-reported fatigue also increased significantly post-task, confirming that the listening task induced the subjective experience of fatigue. These findings indicate that oscillatory power collected from resting EEG before and after a listening task has potential to serve as an objective, brain-based indicator of listening-related fatigue in older adults, with alpha as the most promising frequency band.