This custom molded ear plugs with built in sound looks like an interesting option. Any suggestions where to get these?
Here's one source. You'll often find vendors at bike shows and dealer open house events selling the same thing. Bit of a pain since the good ones require you get custom fitted by taking a mold of your ears (any hearing place should do it for you). Often when they're at shows they can do it on-site and then send them off for you. Also, not cheap.
Earinc/Insta-Mold - Worldwide provider of customized earplugs for hearing protection and communication systems