Place it at the very end of a failed-call or rejected-plan scene, after the setup has played out. Follow it with the SpongeBob Fail sound for a second rejection beat, or put the Dramatic Dun Dun Dun sound just before it as the opening cue, then let the Classic Error sound close the bit.
Об этом звуке
The clip is a repeating telephone busy tone that switches on and off in a steady mechanical pulse for about five and a half seconds. It feels blunt and awkward, like a conversation cut short before it even starts. The tone comes from standard telephony, where it told landline callers that the line they tried was already engaged and the call could not connect.