Great. Now the rest of us have to put up with even more noise.
People wearing headphones make a lot more noise themselves. Presumably because they don't hear the noise they make. Suddenly there's heavy breathing, sighs, grunts, moans, inaudible and sometimes disturbingly audible mumbling, humming &c.
The "normal" state is to be able to tune those out.
Normally people are conscious about the sounds they make and restrict them a bit. If you're coughing in a group, you try to do it softly, or you leave the room. Things like that. When people wear head phones this kind of subconscious self control seems to be a lot less effective.
I'm certainly not the only one to have made this observation.
That’s aside from tapping I might not realize is making noise with headphones on, or a particular motion in my chair that’s making it squeak and I don’t know it because headphones, et c.