美国杜克大学福夸商学院和加州大学圣地亚哥分校的研究人员发现，声音低沉的首席执行官通常都比高嗓门的同僚挣得多，而且为公司服务的年限也更长。

We will never know to what degree Margaret Thatcher's efforts to lower the pitch of her voice influenced her electoral success, but it appears she was on to something.

What worked for the late female former prime minister in politics works for men in business, scientists have found, as those with the deepest voices earn more on average than their higher-pitched colleagues.

The findings come from a study by academics at Duke University's Fuqua School of Business and the University of California at San Diego in the US, who identified speech samples for 792 CEOs from the Standard and Poor's 500 stock index and analyzed the voices to determine vocal pitch.

The pitch levels were then cross-referenced with data on the assets managed by the chief executive, the amount he was paid and how long he had worked for the company.

Factors such as age, education and other facial and vocal characteristics that suggest masculinity were also taken into account.

The scientists found a clear correlation between voice pitch and success, with those with lower voices managing larger companies and earning more.

A decrease in voice pitch of 22.1Hz correlated with an increase in company size of $440 million which was accompanied by higher pay of $187,000 a year.

The researchers also found that male chief executives with lower voices were retained longer by the companies that employed them.

Professor Mohan Venkatachalam, one of the Fuqua researchers, said: "These findings suggest that the effects of a deep voice are salient even for the upper echelons（梯次编队） of management in corporate America."

But his colleague Professor Bill Mayew added: "While a deep voice appears to correlate with various measures of labor market success, we still have little understanding of the precise mechanism by which a deep voice adds value."

Previous research by Duke University has found that voters of both sexes prefer candidates with deeper voices.