Gun Science: Active Electronic Ear-pro deep dive

mannequin-passive-bad-earpro

Not sure what’s more disturbing, the badly fitting ear-pro or the “model” wearing it…

My recent Gear Review of the MSA Sordin Supreme ear-pro barely touched upon the significant differences you’ll find across the price spectrum, and provoked a number of follow-up questions.  The majority of those inquiries can be summarized into three questions:

  • What do you get when you spend more?
  • What are the trade-offs between large, mid, and slim ear cup sizes?
  • What features really matter when I’m shopping for electronic ear-pro?

Let’s dive headfirst down the ear-pro rabbit hole and see what we find…

Hearing protection, commonly referred to as ear-pro, must first and foremost protect your ears from exposure to whatever form of excessively loud noise you expect to encounter.  (Thank you, Captain Obvious.)  As noted in my deep-dive into MSA Sordin performance, the frequency distribution of gunshot noise has specific characteristics which should be considered when selecting ear-pro products.

Simply relying on the NRR number may get you close enough, but doing a little research (that’s why you’re reading this, right?) might help you make a better decision. Beyond the basic question of “does it block enough gunshot noise”, there are five factors I consider important when picking ear-pro.  In no particular order, they are:

  1. Earcup Size And Profile
  2. Fit, Sealing Effectiveness And Comfort
  3. Electronics, Amplification And Sound Quality
  4. Controls, Inputs And Power Management
  5. Cost

 

Earcup Size And Profile

Ear-pro design starts with some simple physics: the larger the ear cups in a circumaural (covering-the-ear) ear-pro headset, the more internal volume you have to stuff with sound-absorbing material.  The lower the frequency of the sound waves, the greater the mass and coverage of sound-absorbing material that’s required to attenuate them before they get to the ear. LPRG rifle-pistol stationsEffectively blocking high-intensity gunshot noise, such as what you will experience when firing a rifle from a shooting position with concrete floor and walls, requires very high levels of sound attenuation to prevent hearing damage.  There are two ways to achieve the required level of protection:

Headsets with very large internal volume can, if properly constructed and maintained, provide the >40dB of sound attenuation needed to prevent hearing damage from the intense reflected gunshot noise of indoor-type shooting.  A prime example of this design principle is the Pro Ears Pro Mag Gold Ear Muffs.  The Pro Mag Golds are basically large-volume passive earmuffs with electronics installed, and in fact Pro Ears sells an inexpensive passive version called the Ultra Pro.  Another reportedly popular large-volume ear-pro headset is the 3M Peltor SV Tactical Pro, though your humble correspondent has only spotted these in the wild a few times in recent years.

Lower-profile headsets combined with earplugs are a practical and comfortable alternative to large-earcup ear-pro, and offer the additional advantage of being a more flexible solution overall.  An added benefit of running “doubled-up ear-pro” aka “plugs-and-muffs” is that you still have a layer of hearing damage if you need to lift up the muffs to adjust eye-pro or simply scratch an itch. I personally prefer and recommend this solution as a first choice, and I wear my MSA Sordins in a variety of configurations:

  • “bare” when hunting or shooting with small groups outdoors on private land
  • in combination with inexpensive closed-cell disposable earplugs when shooting at the indoor-type covered concrete wall/floor positions on Livermore-Pleasanton Rod & Gun’s rifle/pistol range
  • over the extraordinarily comfortable and clear-sounding Earasers Musicians Hi-Fi Earplugs – Medium during classes and some of the louder USPSA matches, when the ability to hear clearly is at a premium
  • over the top of Nuforce in-ear headphones* paired with Comply Tx-400 foam tips for earplug-like protection so I can listen to music while training solo at an indoor range

There’s no one correct answer — anything that gets you to at least 40dB of effective protection will work.  Some people simply can’t stand having anything in their ear canals for an extended period of time, making bulky-but-comfortable options like the Pro Ears and 3M/Peltor SV Tacticals attractive.  Others, such as yours truly, prefer the to combine least obtrusive possible earmuff-type ear-pro with in-ear protection appropriate to the situation.

*Why headphones, when the Sordins have a line-in jack?  Because as great as the MSA Sordin Supreme series is at reproducing speech and ambient sound, they suuuuck at playing music.  The cheaply-made headphones which came free with your last smartphone probably sound 3x better than music through the Sordins.

 

Fit, Sealing Effectiveness And Comfort

Good-vs-bad-earpro-fit

First, and most importantly: it doesn’t matter how much you spend on an ear-pro product if it doesn’t fit comfortably and correctly on your ears and your head.  If you buy a new pair of ear-pro on Amazon based on my recommendation or anyone else’s, and it’s not comfortable after minor adjustments the very first time you wear it, return it immediately.  If the seals don’t quite fit over your ears, or the foam liner rubs/presses your outer ear, or they squeeze uncomfortably on your head, well… that’s not going to get any better over time.

The Howard Leight Impact Sport Electronic Earmuffs are the single most common circumaural ear-pro I see on ranges, second only to $0.50 disposable foam plugs in popularity overall.  For many folks, these are a logical first (and sometimes only) step into electronic ear-pro, and that’s OK. However, they have a significant flaw that compels me to recommend wearing earplugs underneath and turn the volume up a bit to compensate: the HL Impact Sports, depending on the user, range from OK to dangerously bad in how well they seal to the head.  Between the rectangular-shaped earcups and the too-thin foam seals, in my experience the HL Impact Sports fail to seal correctly at an unacceptably high rate.MSA-Sordin-gel-seals

As the reader has no doubt already figured out, the seals on your ear-pro can make or break the effectiveness of the product in protecting your hearing.  You could wear Yeti-sized earmuffs and still suffer hearing damage if they don’t seal well to your head.  Picking your ear-pro according to a few simple guidelines will ensure that it’s at 100% efficiency when the guy with the muzzle-braked 300 Win Mag sets up at the next station:

  1. Gel earcup seals
  2. Oval earcups with openings large enough to fit completely over your ears, worn at an angle which keeps pressure off your ears
  3. Gel earcup seals
  4. Headband/neckband adjusted to provide just enough pressure to keep the earcups sealed to your head size/shape, but no more
  5. Gel earcup seals

The observant reader may have noted that gel earcup seals are highly recommended.  There are several reasons for this:

  • Flexibility: gel seals are “squishier” than foam and are much better at closing up the gap around eye-pro temple stems
  • Sealing effectiveness: gel seals conform to the shape of your head, and in the case of the MSA Sordin seals, are molded to provide an inner and outer ring seal against the head (check out the picture above, you’ll see what I mean)
  • Comfort: gel seals, while they will get sweaty, are far less prone to producing “hot spots” where they touch the head or ears

Long story short, regardless of which ear-pro product you pick, get it with gel earcup seals.  It’s the only way I’ve found to get consistent performance out of any brand of circumaural ear-pro, as sooner or later the foam-core seals cause me discomfort and/or fail to seal properly. If the ear-pro you like doesn’t come standard with gel seals or offer them as an option, well… my law-enforcement friends call that a “clue”.

Electronics, Amplification And Sound Quality

Part 1: Clipping vs Compression

The cheapest and easiest way to build an audio-overload protection circuit is to simply switch off (or “clip”) the sound when the input level at the microphone gets to a certain point, then switch it back on after it’s back to normal levels for a few tenths of a second.  This video is by ProEars, but no need to watch the whole thing if you don’t want to.  The following video is worth a watching, but you might jump straight to 1:49 where there’s a great demonstration of how annoying sound-clipping protection can be:

Overload-clipping ear-pro isn’t so bad when you’re shooting outdoors with a few friends, or at a mostly-empty indoor range.  However, this behavior makes such headsets annoying and even dangerous to use on a busy range or class environment, where hearing commands is important for safety and/or learning. I never, ever judge anyone who has taken their first step into good electronic ear-pro with something like the HL Impact Sports — but I’m always relieved and happy to explain why upgrading to the other type of amplified ear-pro will work so much better.

Fortunately, there is a better way of handling loud sounds: dynamic range compression.  In its simplest form, compression reduces the volume of any sounds over a safe-hearing threshold to a fixed maximum.  Typically, if you set your headset so what you hear is exactly as loud as normal, this maximum will be around 85dB. Really good headsets, though, squeeze the whole dynamic range.

Illustration credit: mp3doctor.com

Illustration credit: mp3doctor.com

Sure, loud sounds are kept below an upper limit, but very usefully, quiet sounds are boosted so that they’re easier to hear.  When coupled with good amplification and high-quality external microphones, compression-type ear-pro can be turned up to give you superhuman hearing when hunting, whether your prey is coyote in the hills of the western US or bad guys in an urban environment.

Part 2: Circuit response time

The better the active electronics in your ear-pro, the more quickly they react to control high-energy noise.  (ProEars calls this “attack time”, referring to the initial climb in sound energy seen on a graph of gunshot noise.)  Pistol and shotgun blast noise happens over a longer period of time than rifle blast noise, which is very sharp and intense as the hypersonic shock waves exit the barrel.  As such, most modern electronic ear-pro does just fine reacting quickly enough to suppress pistol/shotgun noise.

In the case of rifle blast noise, however, the sudden sharp noise of the rifle means you want your ear-pro to react as quickly as possible.  Response times over 5 milliseconds (5ms) start to get into the range where enough of a gunshot-noise spike will get through each time will fatigue your hearing organs over the course of a few hours.  While certain manufacturers (*cough*ProEars*cough) make a big deal about a 1.5ms reaction time instead of 5ms, I have yet to meet anyone who noticed perceptibly different results transitioning to ear-pro with a 1.5ms reaction time.

While the MSA Sordins do not carry a rating for how quickly the respond to excessive noise, they appear to be well within the 5ms reaction time window for not allowing any of the noise “spike” from a rifle shot through to the wearer.  In several months of hard use with pistol, rifle, and shotgun, I have not picked up any of the telltale signs from the Sordins that one gets from electronic ear-pro that is slow to limit input noise.

Part 3: Amplification and sound quality

PSB M4u 2 headphones.  A bit heavy but easily the best headphones I've ever owned.

PSB M4u 2 headphones. A bit heavy but easily the best headphones I’ve ever owned.

It would be challenging and expensive to build a product which perfectly combines external microphones, amplification and dynamic-range compression, passive sound suppression, internal acoustics, and properly balanced internal speakers.  I have yet to experience such a product, but I imagine it would cost over $1000/pair, sound like my PSB M4U2 headphones when playing music, work like my MSA Sordins for compressing and amplifying outside sounds, come bagel-sized earcups and weigh at least a full kilo (2.2lb) with batteries.  In other words, it would be a terrible “compromise product” and 99.9% of people would hate it.

Back in the real world, the HL Impact Sport class of ear-pro uses inexpensive components (speakers, amps, microphones, etc) which get the job done reasonably well without going through batteries too quickly.  It’s great to have that option, and I keep a pair of HL Impact Sports in my bag to loan out when folks I’m coaching show up with passive ear-pro.

At the other end of the spectrum, I’ve found the MSA Sordin Supreme series to be pretty much awful at reproducing music via the AUX port, but stellar at processing sounds like human speech, as well as ambient noise while hunting.  The forward-facing microphones are pretty good at mimicking the directionality of human hearing, making me suspicious that ear-pro which advertises “omnidirectional microphones” would actually be a good thing.

One of my favorite torture-tests for ear-pro is to have a conversation with someone while standing with my head a foot or two away from a fan set to blow a fair bit of air.  Good ear-pro will still enable me to hear the other person clearly, while less-good products will cut out, make the other person unintelligible, or both.  (This is one area where the Sordins both do well and struggle; up to the midpoint of the volume control, they’re great.  Get into amplification, and suddenly it’s Windy City time, and you can hardly hear the other person over the wind  noise.)

Controls, inputs and power management

Or, as Sir Mix-A-Lot might say:

I like big buttons, and I cannot lie

Your knob-controlled ear-pro can’t deny

That when my Sordins turn up, with their compact ear cups

Put those button controls in your face…

Recessed waterproof controls are basically impossible to turn on in your gear bag and as a result are full of awesome, with a topping of awesome sauce.

External knobs, for me, seem to get turned on pretty much constantly during transportation and storage.  In the case of protruding knobs, they get damaged or knocked off as I’m moving my head past some obstacle.  (I take care of my gear, but I do make it work for a living.)

If, as noted above, I ever found an ear-pro product which sounded good enough to use for music playback for 2-3 hours straight, I would start to care about AUX/MP3 inputs.  Back in the real world, I find it a far better solution to shove a pair of reasonably priced Nuforce NE-700M in-ear headphones (with Comply Tx-400 foam tips) into my ears as earplug replacements.  As an added bonus, if I need to step off the range to take a phone call, I don’t have to remove any of my PPE to do it.

I am NOT a fan of anything that uses obscure batteries, such as the N-cells in most of the Pro Ears products.  AA/AAA/123 type batteries are readily available pretty much everywhere, and made in formulations to meet any need including extreme temperatures (lithium-based AA/AAA) and high power draw (123s).

Finally, I consider both extremely efficient battery consumption and an auto-off feature to be desirable if not mandatory.  As mentioned in my review of the MSA Sordin Supreme Pro-X ear-pro, I set a reminder to change the AAA batteries every year whether they need it or not.

Cost

Electronic ear-pro is a textbook-perfect example of “you get what you pay for”…

US$50-75: Overload-clipping electronics, mediocre sound reproduction, questionable fit.. but they’re affordable!

US$100-150: Dynamic range compression (albeit of lower quality), compromises in mic quality, sound reproduction, some water/sweat resistance, may or may not have gel seals

US$200+: Good-to-excellent dynamic range compression, higher quality microphones, highly resistant to sweat and water, either come with gel seals or can easily be equipped with same

If you read this far… I hope you, dear reader, found this to be a helpful reference in selecting active electronic ear-pro.  I know there’s never any shortage of stuff to spend your money on in shooting sports, but good ear-pro is durable goods and will pay you back every time you use it.  Buy the best you can, wear earplugs under your muffs indoors, and get yourself to the range on the regular… then use that starter pair of HL Impact Pros to take a newbie shooting!

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One thought on “Gun Science: Active Electronic Ear-pro deep dive

  1. Pingback: Can you hear me now? | Cornered Cat

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