When I changed from car commuting to bike commuting, I missed listening to the radio. I tried the ear bud once but the background traffic noise was so loud I had to crank up the radio volume. Then I realized how high the volume was turned to. It'd be ruining my hearing. I also realized how pedestrians on the MUPs were oblivious to anyone else when they had their earbuds and headphones on.
Now I carry a pocket radio (a real one) in my jacket pocket close enough to my head to listen.