AGE EFFECTS ON MEASURES OF AUDITORY DURATION DISCRIMINATION

This study examined auditory temporal sensitivity in young adult and e lderly listeners using psychophysical tasks that measured duration dis crimination. Listeners in the experiments were divided into groups of young and elderly subjects with normal hearing sensitivity and with mi ld-to-moderate sloping sensorineural hearing loss. Temporal thresholds in all tasks were measured with an adaptive forced-choice procedure u sing tonal stimuli centered at 500 Hz and 4000 Hz. Difference limens f or duration were measured for tone bursts (250 msec reference duration ) and for silent intervals between tone bursts (250 msec and 6.4 msec reference durations). Results showed that the elderly listeners exhibi ted diminished duration discrimination for both tones and silent inter vals when the reference duration was 250 msec. Hearing loss did not af fect these results. Discrimination of the brief temporal gap (6.4 msec ) was influenced by age and hearing loss, but these effects were not c onsistent across all listeners. Effects of stimulus frequency were not evident for most of the duration discrimination conditions.