The illustration of the hearing system alongside shows that there are external organs to pick up the
sounds, and internal organs to process them into intelligible signals for the human brain.
While the external organs (including the drum) are only partially damageable and can anyway be rebuilt,
the internal ones, i.e. the auditory cilia and nerves, once damaged, are lost forever.
Unfortunately, prolonged exposure to very high noise levels damages the auditory cilia and gradually leads
to complete and irreversible hearing loss. That’s why also noise emissions must be seriously considered
when judging a machine! To do this, just refer to the Use and Maintenance booklet of the machine, checking
the "sound pressure level at the operator's work position" (LpA) in the technical data. Obviously, the lower
this level, the least damage to hearing.
According to current regulations, any level below 85dB does not require personal protection devices nor
check-ups by the factory doctor; beyond this threshold, the employer must apply special precautions for
his workers.































