It's a relatively simple system, but it's very flexible. Some versions link to a soldier's existing communications, and it'll play nicely with hearing aids.

TCAPS is far from ubiquitous. Only 20,000 of the earplugs are in the field, and it's doubtful that every single person in the infantry will get one when they cost around $2,000 a pop. However, it stands a relatively good shot of catching on. More than anything, the technology provides confidence -- you know you'll get crucial audio cues without going deaf.