Mackie MP-220 Owner's Manual page 9

16. Exposure to extremely high noise
levels may cause permanent hearing
loss. Individuals vary considerably
in susceptibility to noise-induced
hearing loss, but nearly everyone
will lose some hearing if exposed
to sufficiently intense noise
for a period of time. The U.S.
Government's Occupational Safety
and Health Administration (OSHA)
has specified the permissible noise
level exposures shown in the chart.
According to OSHA, any exposure
in excess of these permissible limits
could result in some hearing loss:
Duration,
per day in hours
8
6
4
3
2
1.5
1
0.5
0.25 or less
Sound
Level
90 dB
92 dB
95 dB
97 dB
100 dB
102 dB
105 dB
110 dB
115 dB