We aimed to study the influence of age, in normal hearing individuals, on: the masking level difference test, the speech recognition in noise test, the transient evoked otoacoustic emissions test, and the contralateral transient evoked otoacoustic emission suppression test. We also aimed to research the effect of age when using these tests to evaluate the central auditory nervous system. Transient evoked otoacoustic emissions and contralateral transient evoked otoacoustic emission suppression were measured in all subjects. Subjects also underwent masking level difference and speech recognition in noise tests. We found a decrease in transient evoked otoacoustic emission amplitudes, speech recognition in noise scores and hearing thresholds with age. We also found that higher masking level difference values were associated with lower speech recognition in noise scores and contralateral transient evoked otoacoustic emission suppression values. We conclude that decreasing speech recognition in noise scores are associated with decreasing contralateral transient evoked otoacoustic emission supression values. This effect may be related to medial efferent system dysfunction.
