The phrase is Russian for a base station call, with 415 used as the call number and otvetti as an informal spelling of the request to answer. Clips of short radio checks like this circulate on user soundboards because the wording is instantly recognisable even to viewers who do not speak Russian. It has become a shorthand for calling out and getting no reply, which is why creators reuse it in gaming, airsoft and meme edits where a failed communication is the punchline.