RT Journal Article
SR Electronic
T1 Evidence for enhanced neural tracking of the speech envelope underlying age-related speech-in-noise difficulties
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 489237
DO 10.1101/489237
A1 Lien Decruy
A1 Jonas Vanthornhout
A1 Tom Francart
YR 2018
UL http://biorxiv.org/content/early/2018/12/07/489237.abstract
AB When we grow older, understanding speech in noise becomes more challenging. Research has demonstrated the role of auditory temporal and cognitive deficits in these age-related speech-in-noise difficulties, beyond peripheral hearing loss. To better understand the neural mechanisms underlying these difficulties, we recruited young, middle-aged and older normal-hearing (NH) adults, and investigated the interplay between speech understanding, cognitive skills and neural tracking of the speech envelope using electroencephalography (EEG). The stimuli consisted of natural speech masked by speech-weighted noise or a competing talker, presented at several subject-specific speech understanding levels. The results show that healthy aging resulted in a quadratic increase in the speech reception threshold, i.e., worse speech understanding, most pronounced for the competing talker. Similarly, advancing age was associated with a quadratic increase in envelope tracking with a pronounced enhancement for older adults. Additionally, envelope tracking was found to increase with speech understanding, and this was most apparent for older adults. Since the cognitive tests partly explained the variability in envelope tracking, our results support the hypothesis that enhanced envelope tracking in older adults are the result of the activation of a larger number of brain regions for processing speech, compared to younger adults. From a cognitive perspective, this could reflect the inefficient use of cognitive resources, often observed in behavioral studies. Interestingly, the opposite effect of age was found for auditory steady state responses at low modulation frequencies, suggesting a complex interplay of different neural mechanisms with advancing age.New & Noteworthy We measured neural tracking of the speech envelope across the adult lifespan and found a quadratic increase in envelope tracking with age. Using a more ecologically valid approach than auditory steady state responses, we found that young, older as well as middle-aged normal-hearing adults showed an increase in envelope tracking with speech understanding. Moreover, this association appeared to be stronger for older adults.