'It's the Definitive Battle of the Sexes'

Finally, some research you can use.

MEN are more likely to find a woman sexy at her most fertile time of the month, and the sway of her hips isn't the only allure, new research shows.

A study by New York scientists has revealed that a woman's voice is most attractive to a man when she is ovulating.

Australian experts say the find is further proof that women become "different" at this point in their menstrual cycle as they come under the effects of sex hormones.

Research has shown the female lap dancers make more tips during their cycle peak, and another study rated a woman's walk most sexy to men when she is ovulating.

Who said we don't provide useful information?

Professor Rob Brooks, an evolutionary biologist at the University of NSW, said the findings, published in the journal Evolution and Human Behaviour, supported growing evidence that women changed when they were "in heat", otherwise known as oestrus.

"There is a well-established theory known as the battle of the sexes," Prof Brooks said.

"In an evolutionary sense, men with a short-term copulation strategy want to know exactly when a woman is most fertile so they can dip into the action at the last possible moment and get out at the first possible moment."

It is in a female's best interest, however, to conceal her ovulation so they have more control over keeping a man interested long term, he said.

"There's only a handful of days in a women's lifetime when she need a man's sperm but she will potentially need his material resources and parental support for the offspring for many, many years," Prof Brooks said.

"The potential challenge for women is keeping men interested ... so it's understandable that they try to conceal this while men, all the while, try to pick up the signals.

"It's the definitive battle of the sexes."