Place this clip at the end of a prank call scene, right after the dialling sound, so the joke lands as the call fails. Put a Discord Call before it to set up the attempt, then follow it with Dun Dun Dun to hold the beat before the next scene.
About this sound
This is a short automated phone voice, lasting just under three seconds, calmly announcing that the number called is not available. Its flat, matter-of-fact delivery makes the rejection feel final and a little awkward, which is why it lands as a joke when it cuts off an unwanted caller mid-conversation. It works because it sounds exactly like a real dead line.