I have to agree with Terry on this one. I've tried a heap of different "solutions" for rider pillion/bike-bike/music/phone and the autocomm, in conjunction with the Garmin Zumo 550 GPS is the best, by far!.
As a side note, all the units I've tried, really have CRAP speakers for the helmet... and as much as I didn't want to, I decided to try earplugs with built in sounds. Now I'm not talking about the earbud style headphones that are so popular now, but proper in-ear plugs. I decided to try Earmould plugs with the optional add-in speakers. After trying earbuds, which ended up being uncomfortable and downright painfull if worn inside my helmet for any length of time, I was a bit dubious about paying $200 for earplugs... but let me tell you, Earmould plugs are THE BEST option for saving your hearing from wind noise while keeping you in contact with the world. After you've had them in your ears for 2 or 3 minutes and they warm up to body temp, you never notice that they're there. They dramatically cut down the wind noise without removing your ability to hear car horns etc
They actually mould the plugs IN your ears, which is quite an odd experience, but only lasts about 5 minutes while the material sets. Then there's a couple of processes before you leave with your new earplugs. They can be made plain or with speakers and can also be used for ear protection at work if needed. I can't recommend them enough, especially if you use a flip-face helmet as they tend to be noisier than solid helmets... The high-pitched wind noise will, over time, damage your hearing and most likely leave you with Tinitus... just sayin :)