Greg, there is,
NFPA 72
11.5.1.2 Notification
(A) Fire-warning equipment for dwelling units shall provide a sound that is audible in all occupiable dwelling areas.
(B) Where more than one smoke or heat alarm is installed for new construction, they shall be arranged so that the operation of any smoke or heat alarm causes the alarm in all smoke and heat alarms within the dwelling unit to sound.
However, note that it doesn't specificaly say wired together, could be the use of a relay(s) and multiple circuits.
Roger
