in my experience working in hospitals in my area on wards and in treatment rooms phones are supposed to be switched off as they can interfere with some equipment and also be a nuisance if it sounds when drs/nurses/AHP are doing their rounds or even just inconsiderate for patients beside them- some wards don’t enforce this rule but a lot of them do. Some trusts may also do things differently but that’s based on my experienceYou've been allowed phone in hospitals for years!