User Manual

PREVENTION OF NIHL (NOISE INDUCED HEARING LOSS)
NIHL is a preventable condition caused by both one-time and
extended exposure to excessive decibel (dB) levels. This harm to
sensitive inner ear structures is irreversible and people of all ages
can be affected. Damage can happen in a single event or gradually
over time. One-time exposure to sounds louder than 110 decibels
and extended exposure to sounds over 85 decibels can cause harm.
Indicators of NIHL include hearing loss and tinnitus, a condition of
sensing constant ringing, buzzing or roaring. The NIDCD (National
Institute on Deafness and Other Communication Disorders) offers
this simple rule of thumb: avoid sound exposure that is “too loud,
too close or too long.” Here are some general references to sound
levels that occur in everyday life: refrigerator humming (45 dB);
normal conversation (60 dB); city traffic (85 dB); motorcycles
(95 dB); an MP3 player at full volume (105 dB); sirens (120 dB);
firecrackers (150 dB).