New wording in 6.8.6 and 22.214.171.124 adds “Mass Notification System” rules to this section of the 2007 edition:
6.8.6 Fire Alarm and Mass Notification System Notification Outputs.
126.96.36.199 Occupant Notification. Fire alarm and mass notification systems provided for evacuation or relocation of occupants shall have one or more notification appliances listed for the purpose on each floor of the building and so located such that they have the characteristics described in Chapter 7 for public mode or private mode, as required.
As you can see, rule 188.8.131.52 mentions using either “public mode” or “private mode” as required by your state or local building codes. If so required, then 184.108.40.206 allows for “private mode” signaling to be used when it states: Audible alarm notification appliances installed in elevator cars shall be permitted to use the audibility criteria for private mode appliances detailed in 220.127.116.11.
When looking up “private mode” audibility requirements, you’ll find this:
18.104.22.168* To ensure that audible private mode signals are clearly heard, they shall have a sound level at least 10 dB above the average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 1.5 m (5 feet) above the floor in the area required to be served by the system using the A-weighted scale.
The change in wording to “in the area required to be served by the system” from “occupiable areas” allows for certain areas like elevators and stairwells to not be notified. Another change to section 22.214.171.124 from the 2002 edition, eliminates the minimum sound level requirement of 45 dBA and now simply states that being 10 dBA over average ambient is enough noise.
This was never an issue until after September 11, 2001, when all kinds of radical ideas were proposed, including mandating CCTV cameras in the tops of elevator hoist ways to watch for flames. Once we realized that there would be no fire alarm system in the world that would protect a building from terrorists crashing a plane loaded with thousands of gallons of fuel into it, things settled down and the committees got to work writing more practical enhancements. And these are some of those practical rules. Removing notification appliances from areas where they (A) do no good and (B) where they might do harm, makes sense. These new rules aren’t enough to balance out other requirements that don’t make sense, but it’s a start.