The new study, led by professors at Duke University’s Fuqua School of Business and the University of California at San Diego, looked at the voice pitches of nearly 800 male CEOs speaking in public in the U.S.

Past research already showed that in a laboratory, where researchers played voices that had been artificially manipulated to various pitches, people preferred the lower ones as leaders. So this latest report took the study to the next step, seeing if the experiments translated to the success level of real CEOs.

“It appears that the labor market is matching deeper-voiced individuals with larger firms, which means this is influencing boards of directors’ judgments, perhaps,” said William Mayew, associate professor at Fuqua, who headed the study.