Proper Hearing Protection At The Range

Our human senses are some of the most valuable things that
we have. Our hearing accounts for 13% of
all the information we take in. This
sense needs to be protected when engaged in shooting activities. We’re going to
explore hearing protection in this article.

Firearms are loud.
How loud are they? To answer that
question, we need to be able to look at things in the proper context. Sound is measured in units called decibels
(dB). A decibel can describe other forms
of energy, and the name derives from “deci”, meaning one-tenth, and “bel”, an
homage to Alexander Graham Bell. The
scale is not a linear one but rather a logarithmic one. For example, everyday conversational speech
is rated around 60 dB. A sound that is
70 dB is not ten units more, with each unit being equal, but instead, 70 dB is
ten times louder than 60 dB.

This difference can get confusing quickly, but these details
are essential for protecting your hearing.
A noise over 120 dB can cause hearing damage. Where does that put the sound of a
gunshot? Gunshots can be upwards of 140
dB, and from what we learned is 100 times louder than 120 dB, the level at
which instant damage can be caused to your hearing. The 140 dB number is 100,000,000 x’s louder
than everyday speech. That being said,
protecting our hearing is a must!

Hearing protection comes in two forms: plugs, which can be
disposable and are inserted in the ear, and muffs that cover the ears. Looking at the different forms of protection
on the market, disposable plugs, depending on the type, will generally offer
more protection than muffs. There is
also electronically enhanced hearing protection on the market that will amplify
surrounding sound and then cut off the speaker when a gunshot is detected.

Hearing protection is rated by something called the noise
reduction rating (NRR). The NRR of most over-the-ear
muffs are rated to be in the low 20’s and in the earplugs can top out around
33. I’m always on the lookout for hearing protection that can beat these
numbers – but that do so honestly to the standards set forth by The National Institute for
Occupational Safety and Health
.

How NRR actually “lowers” the received sound waves are not
straightforward. There are several
different formulas out there to figure out what effect particular hearing
protection will have. The different
formulas take into account how a set of protection will fit an individual. Your hearing protection may perform better
(or worse) than what this equation gives you, but these calculations were based
on being conservative. The Occupational
Safety & Health Administration (OSHA) recommends using this formula:

Estimated Exposure in dB = Noise in dB – [(NRR – 7) x 50%]

Pulling from what we know, let’s plug some numbers in for 33
NRR plugs and a 140 dB gunshot.

Estimated Exposure in dB = 140 dB – [(33 -7) x 50%]
Estimated Exposure in dB = 140 dB – [26 x 50%]
Estimated Exposure in dB = 140 dB – [13]
Estimated Exposure in dB = 127 dB

This 127 dB level is still above the damage threshold,
seemingly not by much, but nearly ten times louder. These are things that you need to consider
when purchasing hearing protection.

What else can you do to protect your hearing further? Well, you can always double up. What if you decide to use the 33 NRR plugs
along with a set of muffs that are rated at 22 NRR? To figure out the net effect requires yet
another equation. OSHA recommends using
this formula:

Estimated Exposure in dB = Noise in dB – {[(NRR – 7) x 50%] + 5}

Where the NRR is going to be that of the higher of the two
types of protections. In our scenario,
that would be 33. The + 5 accounts for a
secondary form of protection which is the lesser value. Let’s crunch the
numbers:

Estimated Exposure in dB = 140 dB – {[(33 – 7) x 50%] + 5}
Estimated Exposure in dB = 140 dB – {[26 x 50%] + 5}
Estimated Exposure in dB = 140 dB – {13 + 5}
Estimated Exposure in dB = 140 dB – {18}
Estimated Exposure in dB = 122 dB

Doubling up on hearing protection will give you a bit of a
boost in your level of protection.

The intricacies of hearing protection and noise levels go
much deeper than this. This information is
just a tiny fillet of what goes into using and selecting what type of device
you should or may want to use. Other
things such as time-weighted average (TWA), the decibel of noise over a certain
amount of time exposure, and how it affects your hearing also need to be
understood. According to OSHA, being
exposed to a 90 dB noise over 8 hours can also damage your hearing.

The
TWA chart can be found here: 1910.95 – Occupational noise exposure.

From the chart, we have these values:

Time dB
8 hours 90
6 hours 92
4 hours 90
3 hours 97
2 hours 100
1 hour 105
30 minutes 110
15 minutes (or less) 115

Our 127 dB noise exposure does not even come in on the
chart. If we follow the trend, can we
tolerate 120 dB for seven and a half minutes?
Further 125 dB for 3 minutes and 45 seconds? And finally, 130 dB for 1.875 minutes? Can we trust that? Consider a gunshot would last maybe 150
milliseconds
.

Your hearing is precious and valuable. Once damaged, it cannot be repaired. In many instances, hearing damage may take
years to manifest itself. The point
being, this is how important it is that you do wear some form of
protection. What you decide to wear or use
is going to be up to you. Comfort is essential,
as is the level of protection offered.
Read the information on the packaging for any commercially available
hearing protection to make sure they are appropriately rated. You hunters out there, pay heed to this as
well. With different types of enhanced
and amplified protective devices out there on the market, there is no excuse to
go out into the field unprotected!

I recently had the opportunity to discuss hearing protection
with Amanda Suffecool and Rob Campbell on an episode of Eye
On The Target Radio
. Take a listen
to us chit-chatting about all of the above and more HERE.

Stay safe out there and think before you do!

John Petrolino is a US Merchant Marine Officer, writer,
author of “Decoding
Firearms: An Easy to Read Guide on General Gun Safety & Use”
and USCCA
certified instructor, NRA certified pistol, rifle, and shotgun instructor
living under and working to change New Jersey’s draconian and unconstitutional
gun laws. You can find him on the web at www.johnpetrolino.com
on Twitter at @johnpetrolino and
on Instagram @jpetrolinoiii

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