Aging significantly impacts auditory perception, particularly temporal resolution, which is the ability to detect rapid changes in sounds. Temporal resolution is often studied using gap detection methods, where a silent gap is inserted into a longer noise duration. Previous research indicates that aging negatively affects gap detection at the behavioral level. To objectively examine this process, electrophysiological correlates can be studied using a multi-deviant oddball paradigm. Existing data show reduced Deviant-Related Negativity (DRN) amplitudes and increased latencies in older adults compared to younger adults, suggesting a pre-attentive decline in processing basic temporal stimulus features. The effects of aging on gap detection have not been extensively investigated, making it uncertain whether changes can be detected in groups with smaller age differences. This study aims to investigate DRN and P2/P3a components in healthy, normal-hearing young (18-25 years) and middle-aged (30-45 years) adults using a multi-deviant paradigm combined with a behavioral gap audibility task with fixed gap durations. While behavioral task results were inconclusive, DRN latency analysis revealed significant differences during adaptation to deviant stimuli between age groups at various gap durations, displaying opposite slopes between both groups. Specifically, middle-aged participants exhibited increasing slopes, while younger participants showed decreasing slopes. Additionally, middle-aged adults exhibited significantly increased P2/P3a latencies compared to younger adults. These findings not only confirm the impact of aging on DRN during temporal resolution tasks but also suggest that examining the P2/P3a component could be valuable for early detection of age-related auditory decline.