Effects of utterance length and vocal loudness on speech breathing in older adults.

Age-related reductions in pulmonary elastic recoil and respiratory muscle strength can affect how older adults generate subglottal pressure required for speech production. The present study examined age-related changes in speech breathing by manipulating utterance length and loudness during a connected speech task (monologue). Twenty-three older adults and twenty-eight young adults produced a monologue at comfortable loudness and pitch and with multi-talker babble noise playing in the room to elicit louder speech. Dependent variables included sound pressure level, speech rate, and lung volume initiation, termination, and excursion. Older adults produced shorter utterances than young adults overall. Age-related effects were larger for longer utterances. Older adults demonstrated very different lung volume adjustments for loud speech than young adults. These results suggest that older adults have a more difficult time when the speech system is being taxed by both utterance length and loudness. The data were consistent with the hypothesis that both young and older adults use utterance length in premotor speech planning processes.