Speech perception across the adult lifespan with clinically normal hearings by Christian FULLGRABE (MRC Institute of Hearing Research, Nottingham, UK)
Subjective reports suggest that older listeners experience increased listening difficulties in noisy environments, and experimental investigations seem to confirm this age-dependent deficit. However, older persons are generally unaware of their peripheral hearing status (i.e., the presence of a hearing loss) and most published studies used lax audiometric inclusion criteria. Hence, lower speech intelligibility could, at least partially, be explained by a reduction in audibility with age. Also, most aging studies limited their age comparison to groups of ""young"" (e.g. ≤ 30 years) and ""older"" listeners (e.g. ≥ 60 years), making it impossible to pinpoint the onset of the putative age effect. This talk will present two cross-sectional investigations of central age effects on speech perception, using participants with clinically normal hearing. Performance on supra-threshold temporal-processing and a battery of cognitive tasks (including tests of processing speed, working memory and attention) was assessed, and compared with speech identification in quiet and in different (steady and fluctuating) background noises. To determine when during adulthood a decline with age in these abilities first becomes apparent, participants were sampled continuously from the entire adult age range (18-91 years). Despite a large individual variability, the results show an age-dependent decline in speech identification, especially above 70 years. Sensitivity to temporal information and cognitive performance deteriorated as early as middle age, and both correlated with speech-in-noise perception.
