Encoding tasks and the processing of perceptual information in young and older adults.

This study examined the degree to which different tasks promote the encoding of the characteristics of a talker's voice in young and older adults, and whether these characteristics encoded in long-term memory facilitate spoken word identification under difficult listening conditions. During the encoding phase, participants were given extensive exposure to the voices of two talkers and performed tasks that focused their attention on either voice characteristics (explicitly or incidentally) or linguistic information. Subsequently, participants identified novel words masked by noise, half of which were spoken by one of the familiar talkers and half by an unfamiliar talker. Young adults identified with greater accuracy words spoken in a familiar voice, whereas older adults benefited from voice familiarity only under instructions that promoted attention to voice characteristics either explicitly or incidentally. Age-related declines in sensory uptake (hearing loss) accounted for most of these task-dependent voice effects.