Was recently talking to a friend about listening to music while running. He said he usually listens to music at a relatively loud volume while going running, but I expressed my reluctance. I have always been more against than for listening to music while out and about in public as I like to be fully aware of my environment.
However, I may decide to multitask my goals by doing ear training during running. It won’t be a constant barrage of sound as I’ll be listening to single notes and chords for my ear training, and it shouldn’t compromise hearing much of what’s happening in my environment if it’s not too loud.