If you're old enough, you will recognize this sounds and appreciate the spectrogram of a dial up modem handshake. The full video's caption reports a verbal translation/breakdown of the process

\[Full video, Scotty H: buff.ly/3zVFdom (https://buff.ly/3zVFdom)\]

https://nitter.moomoo.me/Rainmaker1973/status/1649423803234111488#m