I'm using these for cycling. Not sure anything is particularly designed for that application, but these do a decent job -- wind noise is reduced, but you can still hear stuff. Certainly everything is quieter, but not crazily so.
I'm not sure how these would go at a concert or something, I don't feel like they'd offer enough protection to really be worth it. They'd certainly reduce the volume somewhat.
I'm using the silicone tips, that might be part of the reason they aren't cutting out a heap of sound. As I said, for my cycling application that suits me just fine.