[Non-auditory responses to noise. Objective estimation. Experimental and individual analyses]

The physiological reactions to a strong noise are immediate and transitory: start, arousal reactions, postural oculo-cephalo-motor response, cardiovascular reactions with tachycardia and peripheral vasoconstriction, mydriasis. The chronic reactions to an occupational permanent noise are mostly a state of fatigue, lowering of the psychotechnic ability, aggressivity, transitory tachycardia and elevation of blood pressure, mainly diastolic. The best argument in favour of a correlation between these reactions and the noise is their reversibility with the cessation of the nuisance. The non-auditive responses to noise--including blood pressure variation--described for stimuli of moderate intensity considered as environmental nuisances are less evident. Among inhabitants of a town the neurophysiological examination of the modifications due to different demonstrate the evident perturbation of the sleep organisation: difficulties to fall asleep, need of a complementary rest. The epidemiological inquiries in noisy zones indicate however that, within a common population, 10% of the subjects feel very uncomfortable, but that 30% of them declare to be normal. The revendications and the trials against the factors of noise let us recommend to associate the efforts of physicians and of physiologists to those of acousticians experts. The different sonometric assays, the methods used in order to decide if a noise is a nuisance are described and should be widely used to demarcate very quiet territories (climatic areas) and sectors to be improved.