We were given those crappy "combat earplugs" with they yellow and brown side. One side had a small hole with a diaphram that would let you hear until a loud noise closed the diaphram. I never wore them because:
1. They didn't fit, way to big form my ears.
2. That small hole still made it very difficult to hear.
3. I couldn't keep the handmic up to my ear without knocking the earplug out.
So I went without them. I did sustain some hearing loss, but nothing critical. I think it was far more benificial to be able to maintain situational awareness. With auditory exclusion I never noticed how loud our weapons were, but I'm sure it still did plenty of damage. It would be nice if they could come up with something that worked. Surefire now has a combat earplug, but it doesn't have a very high noise cancelation rating. Has anyone tried them?
http://www.surefire.com/maxexp/main/.../376/sesent/00
The sonic defenders claim a 9dB reduction, but the PDF file says it will reduce an average of 35dB for sound levels up to 120dB.