It was a hit. Other smart people from across the lab added their two cents, Simon said, and soon he had several partners and the funds to create the prototype.

The ABLE crew has been testing the plugs at a facility on the lab campus, using a device that mimics the effects of an explosion. So far, Simon said, the earplugs have been shown to allow normal hearing pre-blast and to reduce pressure inside the ear by a factor of five or six post-blast. That's still not quite as good as traditional earplugs, but he's working on it.

"That's the bar that we're aiming to hit, to be just as good as traditional hearing protection," Simon said.

The biggest challenge was getting the right material for the poppet, which started out as a polystyrene ball until the engineers realized that the blast shot a pin-prick-thick hole right through the tiny sphere.

The creators debuted the plugs at an event last month sponsored by the lab and the Howard County Economic Development Association. The entities have entered into a technology-transfer partnership meant to help bring lab inventions to the marketplace.

Ben Cruz, who works as a product development, management and marketing mentor with the Maryland Center for Entrepreneurship, checked out the ABLE plugs at the event.

"I though it was really a novel approach to solving a problem," Cruz said. "These earplugs are great because you can leave them in pretty much all the time, and they only protect you from very loud noises when the very loud noises happen."

The next step for Simon and his colleagues is to attract funds from outside investors.

"We're in the proposal-writing stage," Simon said.

He's careful to point out that the ABLE plugs are not like traditional hearing protection, in that they can't prevent damage from other loud, but less intense, sounds, like jet engines. They're meant to protect hearing from the unique blast of an explosion.

"You have hundreds of thousands of guys out there who are susceptible to injury like this, and we owe it to them to prevent as many injuries as we possibly can," Simon said.

tricia.bishop@baltsun.com

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