Temporal integration of the contralateral acoustic reflex threshold for a 1000 hz tonal activator and its age-related changes.

BACKGROUND Previous research has noted an age effect on the temporal integration of the acoustic reflex for a noise activator. PURPOSE To determine whether the age effect earlier noted for a noise activator will be noted for a tonal activator. RESEARCH DESIGN Comparison of ARTs of younger and older groups at activating stimulus durations of 12, 25, 50, 100, 200, 300, 500, and 1000 msec. STUDY SAMPLE Two groups of adults with normal-hearing sensitivity: one group of 20 young adults (ten males and ten females, ages 18-29 years, with a mean age of 24 years) and one group of 20 older adults (ten males and ten females, ages 59-75 years, with a mean age of 67.5 years). RESULTS A significant main effect for duration was obtained. That is, as the duration increased, the acoustic reflex threshold for the 1000 Hz tonal activator decreased. The interactions of duration x age group and duration x hearing level were not significant. There was a nonsignificant main effect (p = .889) for the between-subjects factor of age. CONCLUSION Results contradict the findings for broadband noise.