I constantly preach the use of hearing protection.... but you'd be surprised at how many people turn it down or flat out refuse to try it.
The most common complaint that I hear is that "I can't hear what's going on around me or I can't hear traffic" .. well, this couldn't be farther from the truth.
Your biggest source of noise on a bike is WIND NOISE... and ear plugs attenuate most of it to the point that it makes it EASIER to hear other sounds around you other than wind... cars, bikes, your own bikes mechanics, etc... try it and see, you'd be amazed.
If you aren't currently using hearing protection... give it a shot. I'll be honest, the first few times I tried it I hated it... because I simply wasn't used to wearing hearing protection on a bike. Now if I where to try and ride without hearing protection it would drive me nuts... once you get used to it, you LOVE it!

CCS/WERA Nov. #434 || Official DCSB Trackday Whore