In reply to tony:
> Likewise - I listen to music on the treadmill, but once I'm outside, I far prefer to hear what's going on around me, especially at this time of year - skylarks, curlews, oystercatchers, lapwings, buzzards, the occasional grouse - all part of that good-to-be-alive feeling.
Once I'm outside, I far prefer to hear what's going on around me - fords, toyotas, audis, volkswagons, hondas, the occasional man shouting out of the window "run forrest run!" - all part of that yes-I'm-running-haven't-you-seen-that-before feeling.
Just kidding (though that does happen). I never used to wear headphones, then did for a while, then my mp3 player broke, then tried using my phone but it wasn't comfortable/bit of a hassle to use whilst running, and I haven't since replaced the mp3 player, so now I'm back to listening to the above traffic noise and hilarious commentary. I don't mind it to be honest.
Off-road, it's quite nice to be able to hear whether a young and ethusiastic german shepherd is chasing you or not and, critically, if any golfers are shouting at you. Oh, and the birdlife you mentioned of course!