What is a T-3 pattern?
A T-3 pattern, otherwise known as the three pulse or temporal three pattern, is a sound pattern with three half-second repetitions of the same sound separated by half-second pauses, followed by a 1.5 second pause after the third repetition. The alarm sounds like this: beep beep beep pause, beep beep beep pause, beep beep beep pause. (Note that if your current smoke alarm does not use this pattern, it will not be compatible with Lifetone products.) The T-3 pattern has been used as a standard acoustic pattern in smoke alarms to indicate an immediate need to evacuate.
