Effect of hearing impairment on the click-rate induced facilitation of the acoustic reflex thresholds in older individuals. The Journal of the Acoustical Society of America 99, 4.2, 2561.

This investigation was designed to evaluate the effect of age-related hearing loss on the click-rate-induced improvement in the acoustic reflex thresholds.
Design: Case-control study.
Study sample: Data from five different adults ear-groups (15 ears each) were included in the study: 1. Younger with normal hearing. 2. Older with normal hearing. 3. Older with mild high-frequency loss. 4. Older with moderate high-frequency loss. 5. Older with low- and high-frequency loss. Ipsilateral acoustic reflex thresholds were obtained from the left and/or right ear/s by presenting clicks at the repetition rates of 50, 100, 150, 200 and 300 clicks/s. The rate-induced facilitation (RIF) was calculated by subtracting the lowest acoustic reflex threshold from the highest reflex threshold obtained across the various click-rates.
Results: The click-RIF is significantly reduced in older individuals compared to younger adults. There is no significant difference in RIF across the four older adult groups suggesting that an age-related, mild to moderate hearing loss has no significant effect on the click RIF of the acoustic reflex thresholds.
Conclusions: Click-RIF may allow us to document the effect of ageing on temporal processing within the auditory brainstem area, in a time-efficient and objective manner using commercially available equipment.
Keywords: Ageing; electrophysiology; middle ear; psychoacoustics/hearing science.