Place it at the start of a failed-connection gag, then follow it with a classic error sound to confirm the attempt has failed. For a bigger reaction, close the sequence with a SpongeBob fail sting after the error, keeping the modem moment first so the failure lands in stages.
About this sound
This nearly 12-second clip recreates a dial-up modem handshake over a phone line, with warbling tones, buzzing and bursts of static as the connection stutters. It feels nostalgic and comically frustrating, like waiting forever for a page to load. The sound comes from 1990s home internet, when modems negotiated every connection through the household phone line before broadband replaced them.