Objectives: The relationship between auditory and cognitive functioning in the elderly has been the topic of many investigations, but the role of sensory functions in cognition still remains to be clarified. We performed the study of hearing and cognition using an inbred mouse strain, which allows an age- and hearing-matched longitudinal work with few confounding factors. The mouse auditory system was impaired by noise to investigate whether such an intervention produces cognitive decline as measured by radial arm maze (RAM) and novel object recognition (NOR) tasks during a 7-month follow-up period. Methods:We used 16 male C57BL/6 mice aged 1 month. Eight mice in the hearing loss group were exposed to 110 dB SPL white noise for 60 min everyday for 20 days. At post-noise 7 months, hearing levels were rechecked in all mice before the behavioral tests. All mice underwent spatial learning and memory assessment in an unconfined, partially-bated, 8-arm radial maze in daily trial for 5 consecutive days. Recorded were the total trial time, working memory error, reference memory error, and correct entry ratio. NOR test was performed with the outcome measures of a difference score (novel object contact time ? familiar object contact time) and a discrimination index (difference score/total contact time). Total contact time was also used to compare the baseline motor activity between the groups. Result:After noise exposure, all mice showed permanent threshold shifts of 26-30 dBs. Across the 5 trials, four performance indicators of RAM improved gradually within each group due to learning effect, not showing prominent between-group differences. In NOR test, both indices were significantly lower (shorter contact time with the novel object) in the hearing loss group, which suggests a recognition memory decline in mice with hearing loss. Conclusion:Moderate hearing loss induced by noise in younger mice resulted in cognitive changes related with recognition memory impairment.