In a recent Q&A on the FacilityCare website, consultant Brad Keyes answered a question about occupant notification devices. 

Q: Is there a specific distance that fire alarm audible/visible notification appliances are required to be mounted from other similar devices? We have multiple strobe devices in some rooms but not in others.

A: Wall-mounted audible notification appliances are required to be at least 90 inches above the floor as measured at the top of the device but a minimum of six inches below the finished ceiling. If the audible notification appliance is combined with a visible notification appliance, then the mounting location of the device will be determined by the requirements for the visible notification appliance. Wall-mounted visible notification appliances will be mounted so the entire lens is not less than 80 inches and not more than 96 inches above the finished floor. (Some exceptions for performance-based design apply.)

Read the full answer.