Effect of age-related hearing loss on the click-rate-induced facilitation of acoustic reflex thresholds

Objective: 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.