Etymotic DI-15® High-Definition Electronic Earplugs for Dentists - Manual (Page 2)

2
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Caution
Failure to follow these recommendations may severely
reduce the amount of hearing protection provided by
the earplugs.
• Earplugs comply with EN-352 standard of measurement.
• At very high SPLs (above 125 dB SPL, where the limit to
attenuation is the eartip itself), the foam eartips provide
the most protection.
• Eartips fit ear canal diameters of 6-13 mm. See Eartip
section for details.
• The following applies when the device is turned off
or the battery is drained:
The level of noise entering a person’s ear, when
a hearing protector is worn as directed, is closely
approximated by the difference between the
A-weighted environmental noise level and the NRR.
Example
1. The environmental noise level as measured at the ear
is 92 dBA.
2. The NRR is 25 decibels (dB).
3. The level of noise entering the ear is approximately
equal to 67 dBA.
Caution: For noise environments dominated by
frequencies below 500 Hz the C-weighted environ-
mental noise level should be used. Although hearing
protectors can be recommended for protection against
the harmful effects of impulsive noise, the Noise
Reduction Rating (NRR) is based on the attenuation of
continuous noise and may not be an accurate indicator