Hi,
On safety a listener might always be dammed.
Perception is a powerful thing, it can focus you attention on what might be missed by others.
As someone who likes music and listens to it most of the day whilst I am working I am biased.
Some cannot work whilst listening to music, I can and just blank it when I am focusing on measurement or fine assembly.
If I am doing a for instance a 3D modelling test / competition the concentration is chronic (well for an uneduacated soul like me) so as I remember there was no radio but might of been, some years back.
But concentration on dodgeing trees on a narrow forrest trail is not hampered.
It might be the way peoples minds are wired.
But I find when I am doing mundane tasks then music passes the time.
If you are working hard and with others say on a cycle ride there is so much to ocupy you mind that time does fly.
But in the dark on your own for me it makes time a more bearable thing, especially on my turbo trainer, now thats boring unless you can transport your brain to another place of fantasy.................
Off road cycling is easier as there is lots to see hear and explore, hard long road work with not even a car is mind knumbing for me.
Although I trained for moor walking in teams I spent most of my time doing it alone as with 99 % of my marathon training at night in the dark, and wholly for the last 15 years cycling alone, I have spent most of my working life on my own, something others find impossible.
So If I listen to music I can focus in my task which is only training over the last say 5,000 miles with only one or two leisure rides where I cycle with no goal in mind and I might even sit down and take in the view
My phones dont block out all the noise and when I am in lanes where traffic can come on you with no warning, I turn the volume down, even though I can hear cars round a blind bend they dont slow till after they see you by which time there face is one of alarm, and If I was a car also driven by them then a collision is imminent.............................
On my training rides where there is a few miles of lanes I am constantly looking behind as the hedges can muffle cars and at your speed they barely make a noise at all.
I am not making excuses just saying what I do, car driving sends most of us to sleep on a motorway in few hours, motorcycling lands end to john a groats is easy in a day as the elements keep you awake, your muscles are active all the time in just hanging on.
Cycling is like that and its been said before we are just more alert and tuned in.
If you hate it you hate it, I like it and thats me.