When fire exit drills are conducted between 9 p.m. and 6 a.m., what may be used instead of audible alarms?

Using coded announcements instead of audible alarms during fire exit drills conducted between 9 p.m. and 6 a.m. is appropriate because it ensures that the drills can be carried out without disturbing the overnight residents, particularly in settings like nursing homes or assisted living facilities where alarms could cause confusion or distress. Coded announcements provide a way to alert staff and residents in a specific and calm manner, allowing for an orderly evacuation while minimizing potential panic or disruption.

In these circumstances, a coded announcement can effectively communicate the need for action without the harshness of a loud alarm, which might be disruptive during nighttime hours. It's a balance between safety and the comfort of residents who may be sleeping or in vulnerable states during the late evening.

Visual signals are also a valid alternative under certain circumstances for those who may not respond to audible alarms; however, they do not serve the same informative function as coded announcements. Silent alarms, while useful in some scenarios, may lack the necessary reach or immediacy for a drill context. Manual alarms do provide a means to initiate the drill, but they would typically be audible, and thus not suitable for the specific conditions of the question.