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TETRA Electronic Hearing Protection and Enhancement for Wingshooters

TETRA's high-tech electronic ear devices — the AlphaShield — protects against damaging noises while adding hearing enhancements and comfort for hunters.

TETRA Electronic Hearing Protection and Enhancement for Wingshooters

You’re the only guy in the blind who isn’t laughing at the joke. It’s not that it wasn’t funny. You just didn’t hear the punch line. You won’t hear the whistle of wings as a pair of mallards sneaks into the decoys, either. That’s because your ears have been battered by a lifetime of shotgun volleys. You probably stood too close to the amps at an AC/DC concert back in the day, too, and your off-season weekends include leaf blowers, power tools and chainsaws. It’s no wonder your favorite words are “huh?” and “what?”

Bill Dickinson and David Gnewikow want to change that. They founded TETRA, a hearing technology company aimed at helping hunters and shooters protect their hearing while allowing them to experience the sounds of the marsh even better. The two Nashville-area men aren’t just avid hunters, they are audiologists who work together in a clinic specializing in hearing loss.

“We’ve seen first-hand what duck hunting can do to a person’s hearing,” says Gnewikow. “Many of our patients have suffered mild to severe hearing loss from shooting without (ear) protection. Our goal is to provide a product that hunters will not only use to protect their hearing, but that they actually want to use when they are hunting.”

TETRA’s products aren’t just another hearing device marketed to hunters, agree Dickinson and Gnewikow. There are already lots of hearing protection products available. They saw no point in making a similar device.

“Most of those products are marketed to hunters, but they aren’t made for hunters or by hunters. Ours are high-end products developed for the specific sounds you want to hear when you are hunting,” says David.

The two men aren’t just business partners. They became fast friends when Dickinson interviewed for an assistant professorship at Vanderbilt in 2003. He sat down in Gnewikow’s office and immediately noticed a photo of a hunter posing behind a pile of greenheads. That hunter was Gnewikow.

“There aren’t many audiologists who are duck hunters, so we just started talking about hunting. I don’t think we even talked about the job or audiology,” laughs Dickinson, who grew up hunting in Michigan.

He got the job, not because he hunts, but because he already had an impressive list of credentials. After receiving a Master’s degree from Michigan State, he earned his Doctorate of Audiology from Central Michigan. He worked with the Veteran’s Affairs Administration’s hearing aid program and then at a hospital in Detroit before working for a leading hearing aid manufacturer. When a faculty position at Vanderbilt’s Hearing and Speech Science department opened, he jumped at the chance.


“Taking that job was one of the best decisions I made. The fact that David was an avid hunter and we became close friends was just icing on the cake,” says Dickinson. “We hunt together all the time.”

Gnewikow is equally qualified. He earned a PhD in audiology at Vanderbilt. Research was an important component of his early career, but most of his work focuses on helping patients who have suffered various levels of hearing loss. He’s been running his own practice for 13 years now.

“There probably aren’t two guys on the planet who are more qualified to do this than David and me,” says Dickinson. “David’s research and clinical background and my knowledge of the hearing aid industry allowed us to develop and make such a high-quality product. It also helps that we share a passion for the outdoors. If we aren’t working, there’s a good chance we are in a duck blind.”


That’s exactly where they were when TETRA was born. The birds were flying, but they wanted nothing to do with David’s calls. Bill thought he knew why.

“David was wearing an older set of custom devices and I was wearing a set of prototypes I was developing for the company I was with at the time. He was calling way too loud, but he had no idea. I suggested he try mine and when he started calling, he realized he was unable to hear his call properly with the devices he was wearing,” recalls Dickinson. “That’s when we thought there was a need for a hunting-specific product.”

The concept is similar to the hearing devices worn by musicians on stage. Contrary to popular belief, those ear inserts aren’t meant to suppress sound. Instead, says Dickinson, each set is programmed for the individual musician so they can hear specific sounds while others are blocked. That allows them to play in time and in tune with their fellow band members.


“That’s basically what we’ve done. We isolated certain sounds and programmed our devices to pick up the things we need to hear in the blind,” he adds.

So, are they hearing protectors or sound enhancers? TETRA’s products are both. The Shield line, for example, is designed to enhance and amplify the common sounds of a duck blind while protecting ears from the sudden blast of a shotgun and the ear-splitting high-balls from a duck call. It also picks up the subtle whistle of wings overhead and the distant quacks of passing mallards.

“That’s what I like so much about the Shields,” says Higdon Outdoors marketing manager Kelley Powers. “Aside from protecting my ears when I shoot, I can talk to my friends in the blind without having to raise my voice and I can hear birds. That’s especially important when we are hunting out of layout blinds and we are spaced apart. We can communicate without spooking the birds that are working our decoys.”

You not only hear your friends, you can actually hear the things you’ve missed hearing for years. That’s because Gnewikow and Dickinson spent hundreds of hours analyzing sounds on digital equipment as they passed through their hearing devices. Gnewikow actually spent hour upon hour in his office blowing on a duck call and studying the sound through those high-tech digital processors.

“I think my office staff got pretty tired of me blowing on my duck call all the time, but that was an important part of developing these products. A lot of people tell me they either don’t wear hearing protection or they take it off because they can’t hear how their call sounds. I wanted to know how sounds translated not only outside the ear, but inside the ear through the products we were developing. What you hear without our products is what you hear with them,” adds Gnewikow.

The hard part, both men admit, is simply getting hunters to wear hearing protection and enhancement devices. Surveys have shown that more than 80 percent of waterfowlers don’t wear anything in the field. Why not? Probably because most of us only shoot a few times during a three- or four-hour hunt. What’s a few shots every now and then?

“It’s a cumulative effect. One volley of shots may not seem like a big deal. What many people don’t realize is that each time that happens, your hearing is damaged, even if you don’t notice. You don’t just wake up one morning and realize you can’t hear as well as you used to,” explains Dickinson. “Over time, you find yourself asking people to repeat themselves, or you have a difficult time carrying on a conversation when there is background noise. Eventually, it becomes a significant problem.”

There is a darker side to hearing loss. Research at Johns Hopkins University has shown that those who suffer moderate or severe hearing loss are at a significantly higher risk for Alzheimer’s disease and dementia.

“It’s not just annoying when you have to keep asking people to repeat themselves. It can place stress on personal and working relationships and hearing loss can even be a serious safety issue,” adds David.

Another reason so few hunters protect their ears is a matter of comfort and convenience. Most options—muffs, foam plugs or even electronic devices—are uncomfortable and stifle the sounds we want to hear. We take them off when we talk to our blind mates and we don’t have time to put them back on when a flock of ducks appears. So, we just don’t bother. TETRA fixed that.

“We went through a pretty lengthy testing process to come up with the most comfortable products we could. Bill and I literally traveled the globe searching for the perfect fit that didn’t require making an ear impression. We tested different things in two or three hundred ears of hunters before we were satisfied,” adds Gnewikow.

The AlphaShield is an in-the-ear device. It comes with either silicone or memory foam inserts in three sizes. A custom-molded AlphaShield also is available and is designed for waterfowlers, as well.  

“A lot of people tell me they wear our devices even when they aren’t hunting. That’s how comfortable and effective they are,” says Dickinson.

Who can blame them? Nobody wants to be the only guy at the party who isn’t laughing at the joke.

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