RESUMO
In the last thirty years, several studies have demonstrated a correlation between exposure to noise and the development of alterations and/or pathologies in organs and apparatus, apart from the auditory one. Exposure to noise can induce biochemical, physiological, or psychosocial modifications that can remain either inside the range of biological normality or alter and compromise the psychophysical well-being of the individual depending on the extent of the functional alterations of organic systems and psychosocial functions; both the reversibility and duration of the alterations and the adaptation could be related to the recovery capabilitiy of the human organism and to the environmental condition. Among the factors that can influence the effects of noise we can find: intrinsic characteristics of the physical insult (pressure, sound intensity, emission frequency), extrinsic characteristics (duration of the exposure, way of emission, presence of impulsive components, masking effects), spectral characteristics (infrasounds, ultrasounds, time of recovery) genetic factors (susceptibility) and acquired factors of the human organism (acoustic isolation of the living houses and the social necessity for the industrial activities that generate noise). Other factors that influence the damage are the surprise effect, the semantic content and the identification of the noise source. It can be hypothesized that the extra-auditory effects of noise show themselves through a series of nervous circuits that use the autonomic nervous system and interfere on neuro-immune-endocrine parameters. The organs which are more studied are: cardiovascular, gastro-enteric and endocrine systems, nervous system and psychological effects, respiratory system, fetus and effects on reproductive system, immune system and genetic material.
