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).