I and some of my colleagues wear earphones at work for several reasons, partly for me it helps with the constant tinnitus noise I suffer from, also for me and others because the general buzz of an open plan office is okay but if you have 3-4 people who have naturally louder voices which are impossible to tune out and are regularly complaining talking to people on the phone or face to face it is impossible to concentrate.
Then add in the whistlers, the tappers, the loud always older males yawners/stretchers, it can be a bit much and a pair of earphones at a low levels helps smooth it all out.
My colleague I sit next to can tune out all that without earphones, she doesn't hear it, but if someone puts a radio on it distracts her and she cant concentrate.
Everyone is different and can work best under different conditions, and of course every office environment is different, there are ones where it is not appropriate to listen to music (call centres for example) but in the ones where there is no issue, other than personal preference, micro managing and insisting everyone works your way is not going to get the best out of your team.
Shouting information across an office is not only outdated it is the most inefficient way of communicating to a team critical information, what if one member is out getting a coffee/loo break, on a call, focussed on something and mishears, doesn't need to hear that particular piece of information and it wastes their time and focus having to listen to it, or you forget to shout it out at all? Point proven by a manager who gets "sick to death" with repeating themselves if someone didn't hear something, terrible for team morale. I would listen to my team if they felt a bit a music helped with their roles and find a way my team felt they could work and communicate best not "impose" rules on them.
Sitting on your ass disturbing every team member shouting out you want an email forwarding from one person is efficient for you but inefficient for the rest of your team. There is no I in team.