Researchers have found that women’s voices rise and fall in tune with their fertility -- in fact, the female voice rises a day or two before ovulation when women are most likely to become pregnant.

According to them, the findings are the first to point a link between voice and fertility and built on recent studies that support the idea that humans are similar to other animals in displaying outward signs of fertility.

Lead researcher Dr Greg Bryant said: “Our study shows women change their voice in relation to fertility. The closer they get to ovulation the greater the increase in their pitch.

What we’re saying is by raising pitch women enhance fertility.

They’re turning up everything that makes them attractive.” Dr Bryant and colleagues at California University have based their findings on an analysis of voice recordings of 69 women -- they found that the subjects spoke in a higher pitch when nearer to the time when an egg is released.

But the difference was apparent only when women spoke a simple introductory sentence such as ‘Hi, I’m a student at UCLA’ -- and not for simple vowel sounds. The difference in pitch was the greatest on the two highest fertility days just before ovulation, the British media reported.

“It’s feasible these changes in vocal femininity occur primarily or exclusively during social communicative tasks -- raising the intriguing possibility cues of ovulation appear more during social interactions,” Dr Bryant said.