Is this the time limit to answer each question or the end of a round?
It's the three tone "do-do-do" indicating that nobody else may ring in for that question.
Nathan W. Pyle, creator of the
Strange Planet webcomics, coined the term
Ignorance Tone in one of his comics. I propose we use that term for the "time's up" signal going forward.
ObThread: there is no standard time limit, it's an informal count in the host's mind. I think now it is tied in to the lockout mechanism, though I don't believe it always was. You'd have the tone sound as a contestant's lectern lit up and Alex would say "sorry,
(contestant), not quickly enough". I also read somewhere recently that Mayim was getting the "ignorance tone" button confused with the "emergency stop" button on the lectern, which the host can press if there's an issue with pronunciation, a ruling, etc. Apparently, now she only has the "e-stop" button and the "ignorance tone" is controlled offstage by TPTB.
/Alien!Johnny: "Behold...
PERIL!"