“I think it’s a high G,” Mueller said.

For sports fans, there may be no noise as familiar yet unconsidered as that of the referee’s whistle. The noise is familiar, in part, because most of the whistles used in major sports organizations, including the N.B.A., the N.F.L. and the N.C.A.A., are the same model: the Fox 40.

Image Referees will use the Fox 40 whistle to stop the game clock through a timing device. Credit... Isaac Brekken/Associated Press

The same whistle has been heard at the Olympics and the World Cup soccer tournament, but it was designed with basketball in mind. Starting this week, Fox 40 whistles are expected to be blown about 85 times a game during the N.C.A.A. men’s basketball tournament — roughly 6,000 times in all.

And for the first time, the whistle — not a scoreboard operator on the sideline — will automatically stop the game clock during the tournament, through a Precision Time System carried by every on-court official.

Ron Foxcroft, a former N.C.A.A. referee who lives in Ontario, knows just about everything there is to know about the whistle. He invented it. He knows how it works (three chambers, no pea) and how many are produced (11,000 a day).

But he does not know what note it produces. “No one has ever asked me that,” he said.

Four conference tournaments took place in Las Vegas last week. One, the Mountain West tournament, was held on U.N.L.V.’s campus. A referee offered a whistle, still in the package, to be tested at the music department. The whistle, after all, is an instrument, at least for the roughly 100 referees working the N.C.A.A. tournament.