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If you read the TTAG About Us page – and you know you should – then you know that I’m currently wrapping up my Master’s Degree in Environmental Management. After working for the past 6 years as a chemist in the semiconductor research and development world, my career will be making a drastic switch this spring when I change career paths. Using my chemistry and HVM (high-volume manufacturing) experience, I will focus on hazardous waste and hazardous material management. I also intend to become heavily involved (i.e. CIH certified) in industrial hygiene and worker safety. With that in mind, you can take my word that I get excited about things like ear plugs. Seriously, I do…

Nothing gets me more hot and bothered like NRR ratings, N/P/R classifications, and HEPA filters. OK, so maybe not really hot and bothered, but I certainly appreciate a great fitting, reusable, hypoallergenic ear plug with noise blocking technology. Enter the SUREFIRE Earpro EP4 Sonic Defenders.

Since I’ve been shooting my ARs and rifles more, I’ve been looking for a set of ear plugs to use in place of my Howard Leight Impact Sport ear muffs. Don’t get me wrong – I love my Impact Sports. I even recommended them in my 2011 Holiday Gift Guide. They have served me well in pistol competitions for the last two years.  The issue I am having with the Impact Sports is they won’t stay on my ears when shouldering a long arm, particularly ones with Monte Carlo style stocks.

Boring background info…

Regardless of what some may say, ear plugs are not idiot proof. In the IH (industrial hygiene) world, this type of misconception doesn’t just apply to ear plugs, but rather all types of PPE (personal protective equipment). Many workers and hobbyists are prone to the mistaken belief that all types of PPE are inherently easy to use and are always 100% correctly donned. Well, six semesters of a Master’s program and six years experience says otherwise.

Needless to say, when the Big Brown Truck dropped off the EP4s I was eager to see how they fit and functioned. Having never liked those cylindrical disposable foam plugs (the make my ears itchy after just a few minutes), I always favored the newer “tripled-flanged” style made of silicon-rubber or similar polymer.

One of the major attractions of the Sonic Defenders is that they offer the same triple-flange design that I prefer and are also made from a soft, comfortable, hypoallergenic medical-grade polymer. The added benefit of the Sonic Defenders is that they incorporate something known as a “Hocks Noise Braker”.

The Noise Braker is based on the physics axiom that energy as we know it cannot be created nor destroyed; it is simply just converted to another state. The Noise Braker inside the Sonic Defenders protects your hearing by converting sonic energy into thermal energy by means of compression and acceleration. Of course, you’ll never notice the rise in temperature, but you will constantly be protected from dangerously high noise levels.

At the range…

I had to adjust the earpieces after wearing them for a few minutes. Apparently, my ears are “short” (albeit large) and the cones were extending too deeply into my ear canal. Adjusting the earpiece and stem is done by simply pushing in or pulling out the stem to a comfortable length. After a quick push, the fit was perfect.

I tested the EP4s on the same day that I tested my Remington 700 XCL TLR. I found the EP4s comfortable, easy to put on (in?), and very effective. During the trip, temperatures reached 70 degrees (don’t you just love Phoenix in January!) and my ears didn’t get itchy or irritated – even after four hours of testing. During some of the cease-fires, I did take the EP4s out to let my ears air out and found they were easy to remove and reinsert even while walking back and forth from range bench to target stand.

The Noise Brakers proved to work flawlessly. There were a few silhouette shooters practicing at the same time I was and let me just say, those big pistols can be quite loud. We also had multiple long gun shooters come and go, including a gentlemen shooting his new Christmas gift – a .338 RUM.


The Sonic Defenders come in two styles: the standard EP3 model (16dB NRR) and EP4 Plus with enhanced noise reduction (19dB NRR). Both models can be used with radio communicators, although I don’t have the required equipment to test how well that works. For those who want more “permanent” ear protection, you can insert the stopper into the opening of the Noise Brake and receive a constant 24NRR.

While I’m at it, I have one more side note about NRR ratings. NRR ratings are determined by monitoring noise attenuation across a broad spectrum of sound frequencies and then taking into account a “safety factor.” If you’re bored or afflicted with insomnia, feel free to give the CDC website a once-over.  What this means is that the NRR is a single number (e.g. 16NRR, 19NRR, 24NRR, etc) designed to give users a reliable assessment of how much hearing protection they can expect from a product.

The problem with this rating system and testing method is that they rely on continuous noise sources for calculations. Unfortunately, it may not be an accurate indicator of protection attainable against loud impulse noises. Like gun fire. SureFire has conducted independent testing and found the EP4 Sonic Defenders to be effective in helping to protect against impulse and continuous noise sources.

The size of the Sonic Defenders required is related to the size of your conchal bowl. Yes, you have one, too.  It’s the smaller “c” of your ear and the one directly connected to the ear canal opening. I had to use the “large” size because my ears rival those of a basset hound. SureFire says that the majority of users will be able to use the standard size plugs. The triple-flange canal piece will adjust to fit all sizes of ear canal openings so those remain the same regardless of what size you use.

SureFire states that the life expentancy of the Sonic Defender’s is 3 to 6 months. After using mine, I wiped them down with a bit of rubbing alcohol (as I do with all my PPE) to disinfect. Once dry, I put them back in the included plastic case (don’t throw it away) and put them back in my range bag for next time.

It’s generally understood that noise-induced hearing loss starts at pressure levels of 85 db when exposed to for long periods of time (such as an 8-hr work day), and that noises greater than 140 dB (120 dB for children) will cause some sort of hearing loss. These minute losses add up over time and lead to hearing impairment. The last I checked, a shot fired from a .30-06 registers somewhere above 160 dB. So be smart, use ear protection all the time and not just at the gun range, OK?

Ratings (Out of Five Stars)

Ergonomics: * * * *
While not as simple to use as ear muffs, the Sonic Defenders are easy to insert and fit comfortably, even after hours of use.

Ease of Use: * * * *
Unpack, insert, verify fit, and you’re good to go. Wipe down with a mild soap and water or some alcohol wipes and you’re set for next time.

Overall Rating: * * * *
Get em’ and use em’… while you’re at it, stop using sun glasses and make sure you get real safety glasses for your next trip to the range.

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  1. How does one calculate the effects of doubling up? I’ve heard that you can’t just add up the NRR numbers. I use 33 NRR earplugs with 25 NRR muffs over them. If that were combined into a single number, what would that be?

    • @CarlosT – you are correct. A NRR of 33 and 25 does not equal a 58 NRR. NRR is related to sound pressure levels, a scale that is logrithmic. Doubling up on ears equals about a +5-10NRR, so in your case I would anticipate a solid 30NRR on C-weighted bands.

      • Okay, so that has me confused. So combining 33 NRR with 25 NRR gets me 30 NRR? That seems to imply that I’d be better off with just the ear plugs alone.

        • Sorry Carlos! I meant a solid rating of 40NRR (or at least darn close!)… thanks for catching that!

  2. first tried these out about 5 months ago. they sounded (no pun intended) like a great tool to replace my ear muffs, especially when shooting any long arm, rifle or shotgun. Mounting the stock would bump & effect my shot, also in warm weather my ears would sweat………..i never knew ears sweat…….well anyway, i thought these would be the ticket. In short, they weren’t. i tried them consistently for about a month on about anything that went boom & i could tell WAY TO much boom was getting through. In fact the foam plugs, worked better. If you don’t have $1k for the super duper inside the ear plugs, i use & recommend the poured in molded plugs. Cost me about $40 and they work great. Spend a bit more & really protect your hearing. from someone who has to ask folks to repeat what they said, way to often……….

  3. i totally agree with marty! i was very excited when i got my hands on these, and took them out to the range. after about 3 rounds of .45acp, i tossed them in my range bag and grabbed some $3 foam ear plugs. a ton of loud bang was getting through, and that little plastic flap did absolutely nothing.

    get some cheap foamy plugs or high dollar custom molds, but skip the surefire over priced hype.

    • @foxtrot and Marty – I used these for 4 hours straight at an outdoor range, shooting .30 cal rifles and was next to others shooting other large caliber rifles. Not once did I notice penetration and I never “plugged” the Noise Brake.

      I have since used them to shoot clays and was again more than impressed. I’ve used all types of ear plugs, including the popular “canal caps”, “skullies” (aka Skull Screws), and dozens of foam inserts. Unless these were improperly inserted (i.e. not pushed in far enough), I do not see how they would not peform.

      A quick question for the both of you: were you using the EP3’s or EP4’s? Also, did both of you use yours outdoors, or was it at an indoor range?

  4. I used disposable Howard Leight Ear plugs. 200 pair for $22.50. 33db reduction. They have to be inserted correctly. I see people who just stuff the tip in their ear. You have to roll them and insert them. I can still hear range commands just fine and they are comfortable for hours. I always keep a few extra pairs in my bag and a couple in my car.

    Here is a great video on youtube showing proper fit.

  5. Forgive me if I don’t buy the whole “independent testing” part when conducted for the company selling the product. Sounds like the bottom line is that these provide substantially less protection from acoustic trauma (19-24dB NRR) than slow-expanding foam plugs (typ. 29-33 dB NRR). So these EP3 and EP4s are more expensive and less protective.

    I also had to chuckle at the whole physics explanation of the Noise Breaker (lifted from their website, I see). The majority of the sound with these or with foam plugs is simply not allowed into the ear canal…either by simple reflection (most of the energy) or absorption…which is of course lost as heat.

    • @2A – 3 things to clarify: 1) saying that these are “less protective” is inaccurate. Comparing NRR to NRR isn’t really apples-to-apples. NRR calculations require a reference level, not all of which are equal (depends on testing equipment used). NRR ratings are also based on a C-weighted frequency ranges and testing involves continuous noise. Don’t forget, NRR ratings also assume perfect fit (although a safety factor is taken into account). SureFire is required by law to state what their NRR is according to the ANSI testing method. 2) Obviously most of the noise doesn’t make it through the small opening or through the outer ear. The process I was describing was how the noise that made it into the Noise Brake was handled. I thought that was obvious, but perhaps not. 3) I’m sure the “independent testing” was performed and performed using BKM procedures. In the modern age, no company – particularly not a large company such as SureFire, would “make up” testing results.

  6. I’ve been using a set of these for about a year or so, they work great. I just try to clean and dry them occasionally.

  7. I’ve got a Master’s degree in acoustics, 20+ years experience as a firearms instructor, and 30+ years experience as a regularly gigging musician. In other words, I’m around loud noises all the time, and I know people whose hearing has suffered as a result of similar exposure combined with misuse (or disuse) of hearing protection.

    I couldn’t disagree more with your review. The SureFire earplugs are the hearing protection equivalent of the SERPA holster: a well marketed “tacti-cool” product that doesn’t perform as well as less glamorous alternatives, that actually poses more risk to the user than traditional options. The SureFire earplugs don’t work that well, and that shows in their low NRR rating.

    One of my assistant instructors used to wear them all the time over my objections. He started having hearing problems, went in for a hearing test, and was told that he’s suffered hearing loss, likely from doing too much AR practice with low-performance hearing pro. I bought a set, tried them on the range once, and pitched them because they didn’t work as well as the NRR 19 muffs I show in classes as an example of “junk you shouldn’t buy”.

    People miss because guns are loud, and it’s normal to blink and flinch in response to loud noises. Wearing crappy hearing protection doesn’t help people shoot better, and it can contribute to long term hearing damage. Noise gets into the ear through the eardrum and also through bone conduction. Over the ear hearing protectors provide better protection against this than earplugs, as noted in this scientific journal article If you are going to use your education to back up your opinions in your reviews, you need to do more reading on noise control.

    The bottom line is that most people would be FAR better off using foam earplugs, inserted properly, and wearing an over the ear muff with a cup shape friendly to long gun shooting. ProEars and Peltor, for example, make great electronic muffs that work with long gun stocks, and electronic muffs worn on top of plugs provide good hearing protection *and* the ability to hear when not shooting. Hearing loss doesn’t grow back.

    • @KR – obviously there is some confusion about what I was trying to say in my write-up. I did not mean to imply that the SureFire’s are the be-all, end-all answer to hearing protection. Even those without a college degree can understand that ITE plugs worn under muffs offer greater protection than any ITE plug alone – regardless of salesman claims or marketing lingo.

      Those of us who shoot (or are otherwise exposed to loud noises) and shoot often should be aware of what is required for hearing protection. Indoor ranges, shooting with compensators or muzzle breaks, and other situations demand greater hearing protection. Although SureFire makes the claim that these will attenuate all sound levels down to 85dB, I am the first to disagree. This is the reason I didn’t mention it in the write-up. While the Noise Brakes may indeed attenuate to those levels, that does not take into account the anatomy of the human ear. As you pointed out, bone conduction plays a huge part in human hearing.

      When possible, the greatest amount of hearing protection should be used. For me – I’ve tried a half-dozen traditional and electronic muffs, including 2 types of Peltors. As I said, my Howard Leight’s are the best over-the-ear muff I have found (which is amazing considering their price… I could have bought 5 pairs of them with what I’ve spent trying to find “the one”). However, there are times I simply cannot use them – shooting skeet for example is my biggest problem. Due to my face shape and size, no comb pad, riser, or add-on will let me shoot without “bumping” them off my ears. For the record, the most ineffective type of hearing protection is the one that doesn’t cover your ear when the guy next to you pops off a 12-ga HV round.

      I was using Skull Screws for a long time because they were the most comfortable, although still itchy at times. I also have a hard time hearing range commands, as well as fellow shooters with them in my ears. The SureFire’s offer the necessary protection and as I said, they are all-day comfortable (a first for me). Would I wear these to an indoor range? Of course not. Would I wear them shooting next to a guy with a side-ported muzzle break on a .300 Win Mag? Nope. However, the majority of shooters can safely and effectively use the Sonic Defenders as long as they are used within their limits.

  8. Thanks for the review and because of yours and some others I tried them. I was searching for a flashlight and came across these on the surefire website and I looked up reviews before going in search for a pair expecting them to be expensive but they are not. Long story short I like these surefire plugs. yes I think they work with pistol, shotgun and such but I don’t go to indoor ranges. gun blast is not the reason I bought these anyway. I bought these so my teenage son would wear and keep them in his ears because the foam plugs like one praised so much with video included hurt my ears so much when they expand that I quit wearing plugs for years until Tinnitus got so bad that I had to go back to plugs. I have tried all type of soft ones but they all work out after 10minutes or so and I have to stop and put back in with dirty fingers all day long.
    I like these for use on a bobcat, gator, mower and other machines with it working with a weedeater as well. They have adjustable stem length so take 45 seconds and adjust them. If my 16 year old will wear these for hours at a time and forget they are in his ears then that is better than dirty yellow foam plugs in the floorboard of the truck. The over the ear is not hat and headwear friendly may be ballcap for a gunrange but not hat with a brim in the sun.
    I have been using these for a couple weeks now and I think I have saved some hearing for me, my son and money as well from opening mulitple packs a day of the foam type. Also, like that I can hear the phone ring, conversations and even a dog bark while knocking out loud motor noise.
    These may not work as the only protection with a jackhammer, 50 cal machinegun fire and such but get real guys until you invent something that does stop being so critical like KR and be glad that guys are wearing any type of hearing protection even if not NRR 500’s

  9. These plugs seem like they would be good for quail hunting, when you want to hear rattlesnakes, but also want protection from muzzle blast. But I think surefire should be more complete with their specifications. They report only the NRR when the caps are covering the opening; i.e., when you probably wouldn’t hear the rattlesnake. What about when the caps are off? The caps-out use is what they tout as giving protection while also letting ambient sound in. But they don’t quantify the protection provided. What is the NRR with the caps out?

  10. I purchased two pairs of these (EP4) a year or so ago. These are by far the most difficult earplug to properly insert I’ve ever used. You twist, turn, push, yank, re-insert…and can never get them inserted properly on a consistent basis. Don’t waste your money!

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