Place it after a WhatsApp message sound sets up the chat, let it answer the incoming audio, then close with the stay-quiet warning to finish the exchange without adding another reply.
Sobre este som
This 15-second Portuguese voice clip repeats the phrase 'cala boca' as a blunt, insistent shut-up, delivered in a direct speaking voice that keeps coming back to the same two words. It feels abrupt and teasingly confrontational, like a friend cutting off a rambling story before it goes any further, with the humour landing in the repetition rather than in any setup.