Why Hearing Protection Matters, with the Dynamic Ear Company

Editor’s Note: Before you gloss over this article and deem it “not important” because it doesn’t really feature any “cool gear” — think again. Hearing protection is central to our enjoying music and life to its fullest. The first third of this two-part article is by Mr.T, while the latter two-third is by Sinocelt.

You’ve probably never heard of the Dynamic Ear Company, and in some ways, the Dynamic Ear Company doesn’t want you to know about them. And yet, they’re one of the world’s foremost innovators of hearing protection and protective acoustics.

Formed as a small cabal of engineers within the Netherlands’ Delft University, the Dynamic Ear Company (or DEC for short) is Europe’s counterpart to the US’ Etymotic Hearing. In a somewhat similar manner to Etymotic’s Mead Killion, DEC’s founder, Engbert Wilmink, was a longtime engineer with Sonion and the Netherlands’ TNO research firm, forming DEC after taking a professorial position at Delft. The company’s primary goal is to further innovation in hearing protection technologies, first and foremost.

So, if DEC’s primary customer base doesn’t include audiophiles, why bother to introduce them at all on CYMBACAVUM?

Well, it’s no secret that hearing protection companies understand acoustics quite well, and end up creating very capable and isolating IEMs. Etymotic and Phonak’s (now defunct) Audeo are two very clear examples.

At the same time, audiophiles sometimes need protection as well — protection from themselves. Humans love to listen loudly. Things just seem to sound better that way, regardless of whether it’s a rock concert or a speech. It is CYMBACAVUM‘s philosophy that music enthusiasts and audiophiles alike need to be acutely aware of what dangers may eventually lead to hearing damage — after all, preserving hearing is the best way to derive the most enjoyment out of music.

I first came into contact with the Dynamic Ear Company through its musicians’ hearing protection arm, Crescendo Music. It turned out that their Inor DS-11 (Crescendo Music DS-11) looked a whole lot like the ACS T15 that the UK-based custom monitor company offered as a universal-fit IEM.

The DS-11 is designed to accept either universal tips (that also fit DEC's ear plugs) or custom-molded tips.
The DS-11 is designed to accept either universal tips (that also fit DEC‘s ear plugs) or custom-molded tips.

Inōr DS-11, aka ACS T15 universal-fit IEMs

Designed to be interchangeable with all of the other products of its ecosystem, the DS-11’s tips can be fitted with noise-attenuating filters for CE-certified noise isolation.

The DS-11 is based around a single 2300 series balanced armature driver from Sonion, and little plastic separates the driver and its surroundings, giving the DS-11 its distinctive, small shape. In fact, the DS- 11 probably ranks amongst the top three small in-ear monitors available on the market. Its shape enables it to be readily hidden underneath helmets or just plain hidden.

Beyond musicians, the DS-11 should definitely be applicable to communication purposes for motorsport, military, private security, and more.

But is it any good as an earphone used purely for music?

The DS-11’s greatest strength lies within its diminutive size. If pocketability is a prime issue for you, then the DS-11 should be near the top of your list. It really is that small. Discounting the yet-to-be fully released Aurisonics Rockets, there’s a good chance the DS-11 competes for the title of world’s smallest in-ear monitor. Its dimensions are truly Lilliputian.

The picture below highlights the size of the DS-11:

Measuring at 11. mm and 33 mm tall, the DS11 is absolutely tiny.
Measuring at 11.5 mm tall and 16.5 mm deep, the DS-11 is absolutely tiny.

The DS-11’s stock tips, designed for versatility rather than absolute sound quality, are interchangeable with DEC’s other hearing protection products. In fact, our review sample didn’t even come with tips (retail units will have tips included, however, so no need to worry), and we had to remove the noise attenuation units from the musicians’ earplugs to use them as tips. The two are one and the same, and I have to wonder whether DEC should actually offer both the Musicians’ earplugs and the DS-11 as a bundle package, as musicians definitely need both monitors and earplugs.

My experience with the DS-11 didn’t start off too well. I wasn’t too impressed with the DS-11’s warm, innocuous sound; certainly, it was suitable enough for rudimentary stage monitoring, but the sound was thin, un-involving, and a bit too warm for the neutral palate.

I noticed that the tips extended quite long beyond the exit aperture of the sound port, but kept the same small 1.5 mm diameter opening, and thought that the small opening possibly could’ve been restricting the treble articulation by creating somewhat of a reverse horn effect, so I decided to change tips.

With the HiFiMAN biflange tips fitted, the DS-11 changed character dramatically. No longer did the sound feel mellow and restricted, and was now open and airy. The warm character of the fundamental midrange remained, but felt more in balance with the rest of the spectrum. The bass response felt freer and less stifled, while midrange details previously kept at bay were brought out much more clearly.

The DS-11 (in white), with stock tips that also fit the Filtor noise attenuator system.
The DS-11 (in white), with stock tips that also fit the Filtor noise attenuator system.

When I approached DEC about the possibility of their ear tips not bringing out the full potential of the DS-11, they conceded that the design of the tips was intended as a compromise to fit both its earphones and its earplugs, but did not offer alternatives. I decided to try out HiFiMAN biflange tips that came with the old RE-252/262/272 series, which seemed to sound good with anything. They were wide-bore, stiff-walled, and quite isolating.

The one drawback of the HiFiMAN biflange tips was that with the horn effect boosted the existing 8 kHz canal resonance that had previously been very mild with stock tips, revealing quite a bit more harshness in the music. A big 8 kHz presence also doesn’t do any favors to a company whose primary goal is to protect users’ hearing. After all, 8 kHz is one of the most common sites for noise-induced hearing loss.

Note: We’d intended to provide our own, independent measurements of the DS-11, but ran into troubles with their acquisition, so we’ve affixed the manufacturer’s stated frequency response, which unfortunately only registers from 50 Hz to 10 kHz, too narrow a bandwidth for full music reproduction over 20 to 20,000 Hz.

With its solid sound performance (given the right tips), the Crescendo‘s true strength lies within its modular design, made to fit into their noise attenuator ecosystem. Musicians will be their main clientele by default (look at the number of musician-centric audio companies that use DEC‘s products or have products ODM’ed by them: ACS, Westone, Minerva, and many more), but it doesn’t mean that audiophiles should ignore them.

DEC now offers noise attenuators for nearly any noisy situation, from blocking out the drone of airplanes, to isolating yourself in the office space. They’re also working on releasing an innovative new active noise attenuation system that has piezoelectric mechanical actuators that open and close in proportion to the quantity of noise in the environment.

So really, when thinking about the Dynamic Ear Company, you really should be thinking about hearing protection, and nothing spells hearing protection better than ear plugs.

Next Page: Music Ear Plugs

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2 thoughts on “Why Hearing Protection Matters, with the Dynamic Ear Company”

  1. If i can suggest a possible improvement of the testing method, it would be not to use sine tones, but to use band-limited white or pink noise. You could get away with somewhat fewer bands, the listening could be easier and the results would be less noisy, less affected by narrow band artifacts which don’t play a major role in hearing, more representative.

    Liked by 1 person

  2. Hello! My name is Paul John Stilp and I am very interested in sharing with you a passive hearing protection USPTO patent I have, #6,981,569 under the title: Ear Clip. This particular form of protection uses the actual Tragus(Auricle flap) to seal over the ear canal thereby blocking the majority of harmful extended lower and upper sound decibles. My goal is to share another method to protect one’s hearing by this natural sealing effect. I’ve included an example of a device to satisfy the protocol for the patent prerequisite but made the language clear any device a company may create is perfectly acceptable and not an infringement by any means as long as their product presses against the Tragus thus sealing off sound through the canal entry. My hope is to help, in some small capacity, an additional means for folks who may find the main primary ear plug method difficult to fit correctly, due to what is available they have at work as to product size. I truly believe there can be so many different designs for any company created devices they could dream up enhancing product choices for interested buyers and continued revenue scaling for many years to come. My direction is to license this patent under standard percentage that would seem very fair and certainly beneficial to interested licensees.
    I thank you very much for your time and appreciate any consideration concerning this new approach to hearing protection. Paul. 724-302-9245. pjstilp@yahoo.com. P.S. To view the patent: http://www.google.com/patents/US6981569.


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