I listen to music while training inside, but never outside.
First, for safety. I want to listen for autos, other riders, dogs, and heaven forbid, perverts.
Second, for habit. Music is forbidden in USAT triathlons and I want to train as I will race.
Third, to hear the sounds around me. I want to hear the wind in the trees and the river roaring as I ride up the trail.
My 2 cents
Life is like riding a bicycle. To stay balanced, one must keep moving. - Albert Einstein
In all of living, have much fun and laughter. Life is to be enjoyed, not just endured. -Gordon B. Hinckley