Aging and otitis media as sources of variance in the rat auditory brainstem response

Auditory brainstem response (ABR) latencies were examined in normal female Sprague-Dawley rats at 6 months of age and in 10-12 month old animals which tested positive for Mycoplasma pulmonis, a frequently implicated pathogen in otitis media. Significant differences in the peak latencies of Waves I, II and IIIn were found between the two age groups. A significant age by intensity interaction effect was also identified for Waves II and IIIn. Since the age-related effects observed in Wave I were similarly reflected in Waves II and IIIn, it was concluded that the group differences were due to alterations of the auditory periphery and not to changes in the central auditory system.