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P a g e
Important NRR Information
To the user, the EPA requires the Sonetics Corporation to provide the following information:
Model: NRR User Information (EPA Noise Reduction Rating)
Model (Behind Head) Attenuation Characteristics
Frequency in Hz
Subject
125
250
500
1000
2000
3150
4000
6300
8000
Mean
16.3
15.5
19.8
27.3
31.4
39.2
40.6
41.2
38.7
Std. Dev
2.7
1.9
2.1
2.2
2.7
3.0
3.4
2.8
3.1
Overall device NRR when properly fitted is: = 20dB
Model (Under Helmet) Attenuation Characteristics
Frequency in Hz
Subject
125
250
500
1000
2000
3150
4000
6300
8000
Mean
16.3
16.4
20.4
26.2
32.2
37.0
39.6
40.8
40.0
Std. Dev
3.1
2.1
1.9
2.1
3.5
3.1
3.8
3.0
3.1
Overall device NRR when properly fitted is: = 20dB
Model (Over-the-Head) Attenuation Characteristics
Frequency in Hz
Subject
125
250
500
1000
2000
3150
4000
6300
8000
Mean
13.8
14.3
20.3
28.5
32.4
36.9
40.7
41.3
38.2
Std. Dev
1.7
1.6
2.2
2.7
2.4
3.2
3.4
3.8
3.1
Overall device NRR when properly fitted is: = 20dB
Notice: Improper fit of this device will reduce its effectiveness in attenuating noise (See
fitting instructions).
Important Ear Muff Fitting Instructions
:
•
Inspect hearing protectors for dirt damage and foreign objects each time before you
place the hearing protector / headset on your head.
•
Earmuffs offer excellent protection if the cups are fitted and adjusted properly. Your ears
should be completely enclosed by the ear cups.
•
Adjust the cups up or down to fit the headband securely at the crown of your head. The
best performance is obtained when the cushions form a tight seal against your head.
(See Fitment Section for your specific headset type located in this User Manual)
•
Never attempt to physically modify/bend/overstress the headband which may
compromise NRR rating, proper fit and void product warranty.
•
Test the fit as follows:
1)
In a noisy environment, place the palms of your hands on both cups and push
the cushions towards your head and release.
2)
You should not notice a significant difference in the noise level.
3)
If the noise seems to lessen when you press the cups, your earmuff is probably
not fitted properly (If necessary reposition headset and ensure hat, hair or
jewelry are not interfering with proper fit/seal of the muff pad to head.
•
Regularly check cushions for wear and clean them occasionally as necessary with a damp
cloth or disinfect ear seal surface with non-alcohol PPE wipes. (Do not use harsh
detergents or any solvents which may damage the ear seal over time). Check ear seal
cushions for wear. If the cushions become hard, damaged or otherwise deteriorate, they
should be replaced promptly (Contact Sonetics or your authorized dealer for exact
replacement parts.
•
Warning
: Hats, balaclavas, glasses or other items worn on the head may potentially
prevent proper sealing and reduce the level of hearing protection significantly which can
possibly cause hearing damage.
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 of the protection attainable against
impulsive
noise such as gunfire.
Cautionary Note
: The level of noise entering a person’s ear, when hearing protector is worn
as directed, is closely approximated by the difference between the A-weighted
environmental noise level and the NRR.
NRR Example:
1. The environmental noise level as measured at the ear is 92 dBA.
2. The NRR is (value on label) decibels (dB).
3. The level of noise entering the ear is approximately equal to [92 dB(A) -NRR] dB(A)].
CAUTION
: For noise environments dominated by frequencies below 500 Hz “the C weighted
environmental noise level should be used.’’
Warning
: This communication headset has been sealed by the factory to assure noise
protection rating and lock out dust and moisture and has no internal user serviceable parts
other than the batteries. Do not attempt to open or service the unit as this will potentially
reduce NRR and the ability for the device to protect your hearing. Un-authorized
disassembly, modification or servicing or nullifies warranty and my cause hearing loss or
reduction in NRR rating if the factory seals or calibration is compromised.
