The sound comes from Telefonemas do Nilton, a prank-call segment on RFM, one of Portugal's best-known radio stations, where Nilton phones ordinary people and creates comic confusion with an invented story or request. Short recordings from the segment have circulated online for years among Portuguese listeners, who recognise the format instantly and share favourite calls in chats and on social media. Its lasting appeal comes from its simple radio humour, familiar Portuguese voices and the relatable embarrassment of being caught off guard, which keeps it useful for nostalgic edits and Portuguese-language comedy.