Poster C70, Wednesday, August 21, 2019, 10:45 am – 12:30 pm, Restaurant Hall
Speech perception under effortful listening conditions in older adults
Laura Jagoda1, Pia Neuschwander1, Ira Kurthen1, Nathalie Giroud2, Martin Meyer1,3;1University of Zurich, 2Concordia University, 3Charitè - Universitätsmedizin Berlin
Understanding speech under adverse listening conditions (environmental noise, multiple talker situations) becomes more and more demanding with increasing age. Even with intact peripheral hearing, understanding speech in noise is often impaired in older adults. As speech in noise perception constitutes a difficult task in general, requiring not only sufficient hearing acuity but also a well-functioning central auditory system and a high amount of cognitive resources, deficient speech perception can have multiple causes. On neurophysiological level, cerebro-acoustic coherence, the entrainment of neural oscillations to rhythmic characteristics of the speech input, represents a key mechanism in the most formative models on speech decoding and has been shown to be a correlate of successful comprehension. To disentangle the possible sources of speech-understanding problems in older adults and its neurophysiological underpinnings, we investigated a sample of subjects aged between 65 and 80 years with normal hearing (n = 31) and with mild to moderate hearing loss (n = 44). Participants underwent a comprehensive cognitive assessment (attention, inhibition, working memory) and audiometric testing, including pure-tone audiometry and suprathreshold measurements of frequency selectivity and temporal compression. During EEG recording, participants listened to ~10sec long sentences presented distinctly over hearing thresholds in quiet, in pink noise and in babble noise. We analysed cerebro-acoustic coherence by estimating the phase-locking value between extracted speech envelopes and filtered EEG (2-8Hz). In both groups, the quiet condition induced significantly higher phase-locking than babble and pink conditions respectively. There was no group effect on phase-locking, indicating no significant influence of peripheral hearing loss on the auditory system’s capacity to entrain to the speech input. Cognitive functioning, especially attention and inhibition were found to play a more essential role and exhibited an impact on phase-locking in both groups, highlighting the importance of considering and investigating multiple factors affected by aging, when trying to understand speech perception difficulties in older adults.
Themes: Speech Perception, Control, Selection, and Executive Processes
Method: Electrophysiology (MEG/EEG/ECOG)