triangles
Über Member
Some admit ambient noise through open backs. Others seal the ear canal and use electronics to suppress external sound. And there are stages between those extremes.
I no longer use headphones myself - having been in several accidents (all unrelated to headphone use) I want to minimise any factors that could detract from my focus / safety.
However I remember thinking these looked interesting - http://www.guardian.co.uk/environme.../26/bike-headphones-music-cycling?INTCMP=SRCH