There are a lot of choices out there; many of them so-so (like Sony's earbud line), and some that are very highly regarded. This topic has been covered pretty thoroughly in
www.sport-touring.net so you may want to do a search there (I know because I contributed). About a year ago, I opted for a pair of Shure E3c earbuds and I've been extremely happy with them: the sound quality is excellent, they're built to withstand considerable punishment, and they're very comfortable... what more could you want? The other prime contender seems to be the Etymotic E6i. Frankly anything produced by either of these companies will easily surpass anything Sony has to offer, so save yourself some angst and do a little research on line before you decide. By the way, both the Shure and Etymotic earbuds will fit well under a helmet, but there are several that won't, the 99.95 (list price) Bose offerings for example. Good luck!
Cheers!
