Environmental noise exposure degrades normallistening processes

摘要

To date, the functional and physiological impact on the mature brain of moderate-levelenvironmental noises that do not cause noticeable peripheral deficits remains largelyunstudied. Here we show that exposing adult rats to structured noise at a sound pressurelevel of 65dB, which is markedly below the broadly accepted safety level standard, results inbehavioural impairments and substantially impairs the function of the auditory cortex. Thestrong deterioration in cortical processing of acoustic inputs is independent of the modulationrates of structured noises. Almost equally strong effects result from 10-h daily versus 24-h dailyexposure regimens. These results indicate that there can be substantial negative consequencesfor the auditory system documented at the cortical level, attributable to environmental exposureto structured noises delivered under conditions that do not directly impact hearing sensitivity.These noises are deemed to be ‘safe’ and are often present in modern human environments.