CBS Local– With the quiet crowds during play at tennis matches, fans can hear just about any noise coming from the players. Typically they’re not words but grunts. Listen closely: those grunts can actually be an indicator as who is going to win, according to a study by the University of Essex in England.

As Wimbledon rolls on, pay attention to the grunts. The player whose grunt has a lower pitch is more likely to win.

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Researchers analyzed 50 matches played between top 30 players in the world and measured the “fundamental frequency” or “F0”. F0 measured the pitch of the players’ grunts.

They found that these frequencies didn’t just reveal themselves when matches seemed foregone conclusions towards the end, but when the matches were close as well. The number of grunts increased as the matches went on, but the pitch level didn’t vary and was an indicator of who would win.

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“This suggests that this shift in pitch is not due to short-term changes in scoreboard dominance, but instead, may reflect longer term physiological or psychological factors that may manifest even before the match,” said Jordan Raine, lead author via a press release. “These factors could include previous encounters, form, world ranking, fatigue, and injuries.”

Researchers even found that players themselves could figure out who would win based on the grunts.

“Playbacks revealed that listeners use grunt F0 to infer sex and contest outcome,” the study read. “These findings indicate that tennis grunts communicate information about both the vocalizer and contest.”

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As Wimbledon rolls on, be sure to listen for a lower pitch of grunt for an indication to the winner.