This nearly seven-second MP3 needs little trimming when you want the full sustained alarm, though shorter edits can use its opening hit. Download it once for offline playback or import it into your preferred video editor. Phones that support custom audio can assign the file as a ringtone or notification tone. Lower the gain before layering it over speech because the sharp signal can dominate a mix. For a staggered warning sequence, follow it with a smoke detector beep rather than stacking both sounds together.