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Line graphs illustrating auditory thresholds at different frequencies in ND and ED rats at 3 (A), 6–8 (B), and 12–14 (C) months of age. In both ND and ED animals, mean threshold values rose as the age of the animals increased (B,C). However, at lower and medium frequencies the mean auditory thresholds in the ED6 (B) and ED12 (C) groups, were lower, closer to normal thresholds, than those observed in the ND group.
