Place it immediately after the wild claim in your edit, then follow it with Oh My God Wow, or lead in with Ceeday Huh so this Portuguese line closes the exchange.
このサウンドについて
This two-second voice clip says 'vei, que viagem é essa, vei' in Brazilian Portuguese, a slang-heavy way of asking what kind of trip someone is on. It lands as baffled, amused disbelief, the sound of hearing something so strange that a straight answer feels impossible.