When I ride, I'm very aware of the sounds coming from behind me and I do not like being surprised. I thinkt it s avalid issue, a least for the first few years of more silent cars.
The first few times I rode the Jail Trail, I had a helluva time. I listen for cars and the sound of cars coming up behind me at 70+ mph was disconcerting. Now, before I get on the trail, I take a deep breath and shut off some of my aural awareness.
There was a girl killed by a train east of here recently - she had earbuds on and probably did not hear the train. I'm always astonished that people deliberately cut off their primary danger alert system so they can use music as though it were wallpaper.