Context
Prevention of occupational risks related to noise

To define noise—as well as to measure it—it is necessary to consider two aspects: its physical characteristics and its effects on humans. In terms of physiological acoustics and psychoacoustics, noise is defined as “any unpleasant or disturbing auditory sensation.” From a physical standpoint, it is a phenomenon of mechanical origin consisting of a (very slight) variation in pressure, vibration speed, or fluid density, which propagates by gradually altering the state of each element in the medium through which it travels without displacing matter, thereby giving rise to an acoustic wave (the propagation of “ripples in water” following a disturbance of the surface provides a good illustration of this phenomenon). It is the sensation produced by this wave that is received...