Smoke detector sound effect

One piercing beep with nothing after it, on its own. This is the take most edits want, because the chirp is the sound everybody recognises before anyone explains what it is.

Three hard blasts then silence, the pattern a unit makes when somebody presses it deliberately. It reads as a check rather than an emergency, which is a different scene entirely.

Groups of three repeating with a pause between them, running long enough to lay under a whole shot. The pause is what makes it read as an alarm and not a continuous tone.

The same pattern with the top gone off it and a small echo trailing behind. That colour change is what tells an audience the alarm is somewhere other than where the camera is.

Two clipped beeps close together instead of one. The doubling is the detail that separates a unit asking for a battery from a unit asking to be replaced.

A blast stopped dead partway through by a soft acknowledgement beep. Useful when the point of the moment is somebody silencing the thing rather than the alarm itself.