Spoken word recognition in listeners with mild dementia symptoms

BackgroundDifficulty understanding speech is a common complaint of older adults. In quiet, speech perception is often assumed to be relatively automatic. In background noise, however, higher-level cognitive processes play a more substantial role in successful communication. Cognitive resources are often limited in adults with dementia, which may therefore hamper word recognition. ObjectiveThe goal of this study was to determine the impact of mild dementia on spoken word recognition in quiet and noise.MethodsParticipants were adults aged 53–86 years with (n=16) or without (n=32) dementia symptoms as classified by a clinical dementia rating scale. Participants performed a word identification task with two levels of neighborhood density in quiet and in speech shaped noise at two signal-to-noise ratios (SNRs), +6 dB and +3 dB. Our hypothesis was that listeners with mild dementia would have more difficulty with speech perception in noise under conditions that tax cognitive resources. ResultsListeners with mild dementia had poorer speech perception accuracy in both quiet and noise, which held after accounting for differences in age and hearing level. Notably, even in quiet, adults with dementia symptoms correctly identified words only about 80% of the time. However, phonological neighborhood density was not a factor in the identification task performance for either group.ConclusionThese results affirm the difficulty that listeners with mild dementia have with spoken word recognition, both in quiet and in background noise, consistent with a key role of cognitive resources in spoken word identification. However, the impact of neighborhood density in these listeners is less clear.