The bigger point which most have affirmed and I will further reinforce is moderation and mutual respect. We've had issues with it on nearly all of the same fronts as others and run a casual, friendly business where we play tunes, ball games, news, etc. all at any employee's whim to change with a "no shorts in a bunch" policy about it. Over the course of a day, week, month or year, I or anyone else here gets to pick their listening choice multiple times. We actually turn it into a contest to see who can come up with music nobody has ever heard of. We're not running a slave trade here and want folks to enjoy their day as much as possible until it becomes a distraction from the business at hand.
Our flatbed printer's vacuums make some noise, but not so much that one finds it intolerable or requiring headphones in order to tune it out like our most recently departed employee tried to justify. Everybody here helps cover phone calls, walk ins, etc. and we expect people to be attentive enough to do their fair share of those tasks.
Being a husband/wife company I'm not concerned about emergency calls for ourselves except about a relative or friend living back home. Having received multiple "Tim, its your dad, your step mom has just died suddenly" type calls since moving away from home 30 years ago and as recently as last February, I'd never be dismissive or too regimented about an employee's ability to receive such calls regardless of the device. Open communication and empathy for others are hallmarks of decent, considerate, mutually respectful people and we maintain and value those character traits. Others may not value them or are so misanthropic that it doesn't matter how others feel, but when my mother in law suddenly died while living in Portland, OR, we were on a flight and in Chicago within six hours. Yes, we couldn't have saved her or changed anything, but to be there to help my father in law and wife's siblings cope so quickly was greatly appreciated.
We leave the shop often and I'd hate to be out on an installation with an employee whose parent just died and they didn't find out about it until we returned to the shop hours later because I locked their phone in a box somehow.
I am concerned about distractions, safety issues and outside interests occupying too much of an employee's already compromised attention span.
Talk to your people, spell things out, make sure they understand, reward those who cooperate, get rid of those who don't.