Our hospital only usually uses the overhead paging system for emergencies or when the digital pagers aren't working. A loud tone sounds, followed by "MEDIC" and either the room number or the unit. Whoever happens to place the 911 call to switchboard either gives them the room number or just the area. Like most anywhere, there's enough people on the area to direct traffic if just the area is given overhead. No other notification is given to ancillary depts or staff, the ICU or CCU nurse responds based on which part of the hospital it's in, also the nursing supervisor, EKG, pastoral care...