January 26th, 2019

Suppressors — Why You Still Need Hearing Protection

suppressor silencer moderator facts fiction sound levels noise decibles dB
Silencer-equipped AR photo courtesy The Silencer Shop.

OK, you’ve paid the tax stamp and acquired your new suppressor (aka “silencer” or “moderator”). Do you still need to wear earplugs or muffs? Absolutely. Even with that expensive new “can”, your rifle could be generating over 140 decibels (dB) of noise — about the same as as an unmuffled 9mm pistol shot. That’s loud enough to create permanent hearing loss with repeated exposure.

Firearms Are Loud: 140 dB to 175 dB

Audiology group ASHA explains: “Exposure to noise greater than 140 dB can permanently damage hearing. Almost all firearms create noise that is over the 140-dB level. A small .22-caliber rifle can produce noise around 140 dB, while big-bore rifles and pistols can produce sound over 175 dB. Firing guns in a place where sounds can reverberate, or bounce off walls and other structures, can make noises louder and increase the risk of hearing loss. Also, adding muzzle brakes or other modifications can make the firearm louder. People who do not wear hearing protection while shooting can suffer a severe hearing loss with as little as one shot[.] Audiologists see this often, especially during hunting season when hunters and bystanders may be exposed to rapid fire from big-bore rifles, shotguns, or pistols.” Source: ASHA, Recreational Firearm Noise Exposure.

suppressor silencer moderator facts fiction sound levels noise decibles dB

Suppressors, On Average, Reduce Noise Levels about 30 Decibels
In an article for Ammoland, gunwriter Sam Hoober says that you can expect about 30 decibels (dB) of noise reduction from the average suppressor: “Looking at a few different products, SilencerCo attests their suppressors reduce the sound pressure of a 9mm gunshot to anywhere from 125.7 dB to 131.5 dB, depending on the model. Advanced Armament Co, another popular supplier, attests a 23 dB to 33 dB reduction or down to 127 dB. Liberty Suppressors, another manufacturer, attests a reduction of 24 dB to 38 dB, depending on model and other factors. In short, we can presume something on the order of 30 dB of attenuation as an average.”

Using that 30 dB number you can quickly discern that you’ll still need hearing protection — good hearing protection — when shooting any suppressed firearm (even a .22 LR). “Spikes of 130 dB and more can result in permanent hearing damage instantly”. Source: NRA Blog.

The Myth of the “Quiet” .22 LR
The NRA Blog notes that “many rimfire shooters, particularly those using the beloved .22 Long Rifle cartridge, argue that the small .22 LR caliber doesn’t produce enough sound to damage your hearing”. So, is that really true. or is it a myth?

In fact, a .22 LR can be much louder than you think — a .22 LR pistol can produce sound levels of 134 dB. That’s well above the normal human pain threshhold.

Sound Levels for Common Noises:

9mm Luger pistol: 160 dB

Jet aircraft engine (near): 140 dB

.22 LR pistol: 134 dB

Normal human pain threshold: 120 dB

Noisy Nightclub: 110 db

Riding Motorcycle at 65 mph: 103 db

Power Lawnmower: 95 dB

Hearing damage possible: 85 dB (sustained for 8+ hours)

Ringing Telephone: 80 dB

Normal conversation: 60 dB


The Risk of Hearing Loss
Hearing loss can be progressive and irreversible. If you are a shooter, this is serious business. As the NRA Blog cautions: “You may not even realize you’re harming your hearing. Hearing loss occurs gradually, and can go effectively unnoticed until symptoms become severe. By then, the damage is done.”

Nobody wants to go deaf. But we often see shooters without effective hearing protection when they are walking around a few yards behind the firing line. That’s bad — even if you are away from the firing line, gunshot noises can damage your hearing. You MUST use effective hearing protection every time you go to the range. Good foam earplugs costs mere pennies but they can prevent deafness in your later years. Many folks also wear muffs over plugs.

Permalink Hunting/Varminting, Tech Tip 2 Comments »
December 29th, 2011

New ‘Quiet-22′ Rimfire Ammo from CCI — Just 68 dB of Noise

CCI quiet-22 Rimfire ammunitionHow would you like to be able to shoot a rimfire rifle or pistol that only makes 25% as much noise as a standard .22 LR gun? And no, we’re not talking about a suppressor-equipped firearm. CCI claims that its new Quiet-22 rimfire ammo “generates one-quarter the perceived noise level of standard velocity .22 LR rounds.” So this stuff is very quiet indeed, and it’s also affordable — a 50-round box sells for under $4.00 at major online vendors.

CCI’S 710 fps Quiet-22 Ammo only produces 68 Decibels (dB) of sound at the shooter’s ear (compared to 132-139 dB for a standard .22LR). How do we put that in perspective? Consider this: 68-70 dB is the noise level inside a typical family sedan cruising at 70 mph. For additional comparisons, a typical alarm clock ringer produces 80 dB of noise, while a hair dryer can deliver 90 dB. The sound levels at rock concerts can top 115 dB, and a chain saw can hit 125 dB.

To achieve its low sound levels, CCI’s Quiet-22 ammo sacrifices both speed and energy. Rated velocity is just 710 fps, and the 40gr LRN bullet only has about 36 ft-lbs of energy at 100 yards. So this ammo may not be a great choice for varminting, except for very small prey. On the other hand the ammo could be ideal for short-range plinking and fun shooting. For paper punching, CCI notes that Quiet-22 ammo offers better performance than an air rifle with similar noise levels. CCI’s Quiet-22 Ammo may also be perfect for areas where shooting is allowed, but noise pollution is a concern.

CCI quiet-22 Rimfire ammunition

Do You Need To Wear Muffs?
CCI says you can shoot this ammo without hearing protection. The 68 dB report of this ammo is well below the 85 dB(A) noise level at which OSHA requires hearing protection in the workplace. However, remember that, when you’re at a range with other shooters, you must shield your ears from the noise produced by other firearms. So even if you use Quiet-22 ammo, you’ll need muffs/plugs if other shooters nearby are using conventional rimfire and centerfire ammo.

Permalink Bullets, Brass, Ammo, New Product 14 Comments »