NFPA 72, National Fire Alarm and Signaling Code, explicitly states the mounting height requirements for audible notification appliances to ensure effective sound distribution. The code mandates that the tops of wall-mounted audible appliances be located not less than 90 inches (2.29 m) above the finished floor. This placement helps the sound waves travel over potential obstructions like furniture, cubicle walls, and stored materials, thereby improving audibility throughout the space. The appliance must also be mounted with its top at least 6 inches (152 mm) below the ceiling.

A. 80 in. (2.03 m): This is the minimum mounting height for the entire lens of a wall-mounted visual notification appliance (strobe light), not an audible appliance.

B. 88 in (2.23 m): This value is not a specified minimum or maximum mounting height for notification appliances within NFPA 72.

D. 96 in (2.43 m): This is the maximum mounting height for the entire lens of a wall-mounted visual notification appliance, not a minimum for an audible one.

1. NFPA 72, National Fire Alarm and Signaling Code, 2022 Edition, Chapter 18, "Notification Appliances," Section 18.4.7.1.

2. SFPE, Handbook of Fire Protection Engineering, 6th Edition, Chapter 49, "Detection of Fires and Special Hazards," Section 49.5.2.2, "Location of Notification Appliances." This section discusses the placement rules for audible and visible appliances as derived from NFPA 72.

3. Oklahoma State University, Fire Protection Publications, Fire Alarm Signaling Systems, 4th Edition, Chapter 6, "Notification Appliances," page 138. This text, used in university fire protection programs, states, "Wall-mounted audible appliances must be mounted so their tops are at least 90 in. above the finished floor..."