Place it right after the on-screen captcha fail, before any commentary, so the denial answers the prompt directly. Follow it with a wrong answer gameshow sting for a second failed attempt, then return straight back to your normal audio.
关于此声音
This is a short voice clip of someone saying the Hungarian phrase Nem vagyok robot, which means I am not a robot, delivered as a plain declaration. It feels funny and slightly exasperated, like a human protesting a captcha challenge that will not believe them, and that deadpan denial is what makes the line instantly relatable.