Effects of adult aging and hearing loss on comprehension of rapid speech varying in syntactic complexity.

Comprehension of spoken language by older adults depends not only on effects of hearing acuity and age-related cognitive change but also on characteristics of the message, such as syntactic complexity and presentation rate. When younger and older adults with clinically normal hearing and with mild-to-moderate hearing loss were tested on comprehension of short spoken sentences that varied in syntactic complexity, minimal effects of age and hearing were seen in comprehension of syntactically simpler sentences, even at rapid speech rates. By contrast, both age and hearing loss were associated with poorer comprehension for more syntactically complex sentences, and these differences were further exacerbated by increases in speech rate. These findings illustrate a dynamic interaction between age, hearing acuity, and characteristics of the spoken message on speech comprehension.