Saving Your Hearing at Cabela's

Saving Your Hearing

Author: William F. Kendy

Safety is all the buzz in the shooting industry today, whether it’s in the field or on the range. And safety goes beyond trigger and cable locks; it also encompasses the need for hearing protection.

Hearing protection has come a long way and is becoming more popular with shooters and hunters. I’ve talked to veterans who told me that their hearing protection was either a rolled up piece of cotton or an empty .45 caliber A.C.P casing squeezed into their ears to muffle the sound. Those days are long gone.

The ear is a very sensitive organ. Thousands of cilia (tiny hair-like cells) inside the ear receive vibrations from the eardrum. These impulses are passed along to auditory nerve, then to the brain. When the ear is exposed to loud noises (anything over 100 decibels), fragile cilia are damaged. Unfortunately, we don’t replace cilia. Once they are damaged, they are always damaged. Even noise levels above 85 decibels can be permanently damaging if the listener is continuously exposed and doesn’t wear some type of ear protection.

How loud are different types of firearms? Here’s a basic list of peak sound pressure levels (decibels).

.44 Magnum Revolver - 164
.357 Magnum Revolver - 164
.30-06 Rifle - 159
.45 Automatic - 157
.38 Revolver - 158
12 Gauge Shotgun - 156
.223 Rifle - 155
.22 Rimfire Revolver - 152
.22 Rimfire Rifle - 134

(Source: Dr. William Kramer, Ph.D.)

Compare those levels with that of a standard power lawnmower (85 dB) or a jet taking off from 100 feet away (130 dB) and you can see how consistent exposure to shooting without ear protection can cause hearing loss.

According to Dr. William Kramer, a Ball State University Professor, the biggest culprit when it comes to hearing loss is the little .22 rimfire.

"Rimfire rifles are the single worst ear killers I know of," says Kramer. "People don’t realize that the .22 generates enough noise to eventually damage hearing and that damage is permanent."

The insidious thing about hearing loss is that it happens just a little bit at a time and has a cumulative effect. Before you know it, you’re leaning over the table to hear someone talk. It just sneaks up on you.
Walker’s Game Ear is effective and compact
"Hearing protectors are rated according to the protection provided and have a Noise Reduction Rating (NRR). The NRR is a calculation of how much noise a hearing device limits from your ear, and the act of limiting that nose from reaching your ear is attenuation. The higher the NRR, the more the ear protection you receive.

To determine how much damaging noise reaches your eardrums, when wearing hearing protection, subtract 3 dB from the difference between the unprotected and the protected levels at the ear. For example, If you wear hearing protectors rated at 30 dB while shooting a .22 rimfire handgun that produces 152 dB of noise, your ear will hear roughly 122 dB. If you want the technical explaination, see the chart at the end of this article.

According to Kramer, one thing to keep in mind is that decibels are measured logarithmically. In other words, a sound measuring 20 dB is nearly 10 times as intense as one at 10 dB.

"In the logarithmic nature of decibels, a jump from 100 to 110 dB is not the same as a jump from 160 to 170 dB," says Kramer. "To put it in perspective, if you have $50.00 and ask a friend to give you ten times that amount, you have $500.00. But if you start with $50,000 and try to get ten times as much, you’re now asking for $500,000."
Walker’s Power Muffs give maximum protection.
Today, manufacturers offer a broad range of different kinds and levels of ear protection devices, including standard plugs, electronic plugs, passive earmuffs, combination eye and ear protection and high tech electronic muffs.

One form of ear protection is the simple foam earplug. These come in a multitude of styles with NRR ratings ranging from 25 up to 33. The nice things about plugs are they are inexpensive, lightweight, handy and easy to use. Some plugs are meant for one time use while others can be washed and reused. The use of foam plugs, along with a set of passive earmuffs, further reduces harmful noise, especially when you’re shooting in an indoor range.

Standard passive earmuffs have come a long way. Today’s muffs are lightweight, less bulky and have NRR ratings up to 31. Some muffs incorporate both hearing and sight protection by having a pair of shooting glasses attached. The only drawback of passive ear muffs is, like ear plugs, they block out not only harmful sound, but muffle normal conversation, which is a consideration when listening for instructions on a shooting range.

Enter the age of electronic earmuffs
Electronic earmuffs are becoming more popular with today’s shooters and hunters. The concept behind electronic muffs is to reduce harmful sound, with still allowing a shooter or hunter to hear normal conversation. Through sound compression, harmful noises are reduced to between 70 and 84 dB, while normal sounds can be amplified up to 8 times, depending upon the model. The amplification feature is valuable for hunters, who may have some hearing loss, to hear that trophy deer, elk or turkey trying to sneak away.
E.A.R. and Silencio noise reducting ear muffs
Electronic earmuffs are available from Remington, Howard Leight, Aearo, Ridgeline, Silencio, Browning, Walker’s Game Ear and a number of other manufacturers. And the technology is going to greater heights. For example, the Pro Ears Dimension 2 series of electronic muffs offers the capability of plugging in radios, TV’s, Phones and CD players. The Dimension 3 series allows input and output for complete communications. By plugging into two-way radio communications, you can talk to other hunters in your party from a distance.

The discussion on hearing devices wouldn’t be complete with mention of electronic earplugs. One model is Walker’s Game Ear. The Game Ear resembles a behind the ear hearing aid that combines sound amplification with protection from loud gunshot noises. The unit itself weighs less than 1/4 ounce and powered by a 1.4-volt hearing aid battery. Walker’s also offers the Game Ear III, which also allows for wireless communication when used with a portable radio.

With all the new and neat hearing protection devices available, there’s no excuse for a hunter or shooter to ever have to ask, "What did you say?"

For More Information On Hearing Protection Click Here.
The NRR (Noise Reduction Rating) Formula The NRR is a single number rating which is required by law to be shown on the label of each hearing protector sold in the United States. The NRR is specified by 40 CFR code of Federal Regulations, Part 211, Product Noise Labeling, Subpart B - Hearing Protection Devises. It (the NRR) is independent of the noise spectrum in which it is applied.

The values of sound attenuation used for calculation of the NRR are determined in accordance with ANSI S3.19-2974, "American National Standard for the Measurement of Real-Ear Hearing Protector Attenuation and Physical Attenuation of Earmuffs." The NRR calculation assumes a pink noise with octave-band levels of 100dB. Thereafter various correction factors for C-weighting scale and A-weighting scale are introduced. The octave-band noise levels are logarithmically summed to obtain the overall sound level in dB(C) and dB(A). The NRR is computed by subtracting 3 dB from the difference between the unprotected C-weighted and the protected A-weighted levels at the ear.
Computation of the Noise Reduction Rating
Octave band center Frequency, Hz 125 250 500 1000 2000 3000 4000 6000 8000 Log Sum
1. Assumed pink noise (dB) 100 100 100 100 100   100   100  
2. C weighting corrections (dB) -0.2 0 0 0 -0.2   -0.8   -3  
3. Unprotected ear C-weighted level 99.8 100 100 100 99.8   99.2   97 107.9
4. A weighting corrections (dB) -26.1 -8.6 -3.2  0 1.2   1.0   -2.1  
5. Unprotected ear A-weighted level 83.9 91.4 96.8 100 101.2   101   98.9  
6. Average attenuation at each frequency (example) 21 22 23 29 41 43 47 41 36  
  21 22 23 29 41   45*   38.5*  
7. Std. deviation in dB at each frequency (example) 3.7 3.3 3.8 4.7 3.3 3.3 3.4 6.1 6.5  
  x2 x2 x2 x2 x2          
8. Two standard deviations 7.4 6.6 7.6 9.4 6.6   6.7**   12.6**  
9. Complete APV-98 in dB at each frequency.
(Line 6 - line 8) (APV = Average Protection Value)
13.6 15.4 15.4 19.6 34.4   38.3   25.9  
10. Protected ear A-weighted level,
(average attenuation minus two std. deviations
develops the A-weighted levels (line 5 - line 8))
70.3 76.0 81.4 80.4 66.8   62.7   73.0 85.1
11. NRR is unprotected ear "C" level (line 3)
minus protected ear "A" level (line 9) minus 3 dB
* Average attenuation at 3000 and 4000 Hz and at 6000 and 8000 Hz.
** Summed standard deviation for 3000 and 4000 Hz and 6000 and 8000 Hz.
Source: NIOSH Hearing Protector Compendium
When C-weighted sound level measurement is available, the following formula should be used to calculate the required NRR
Noise Level in dB(C) - Protector NRR = 90 dB(A) or less.
When A-weighted sound level measurement is available, the following formula should be used to calculate the required NRR.
Noise Level in dB(A) - (Protector NRR - 7 dB) = 90 dB(A) or less

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