A fascinating study just published in the Archives of Sexual Behaviour looked at the link between womens vocalisations during sex and the timing of orgasm during heterosexual encounters, finding that there was little connection with female climax but a strong link with male ejaculation.
The researchers draw the ego-denting conclusion that womens moans and sighs are not an involuntary reaction to male sexual prowess, but a way of exerting influence over their partners sexual response.
In the study, many of the women also explicitly reported what the researchers coyly labelled a tactical use of copulatory vocalizations as a specific sexual strategy.
This manoeuvring of male behavior not only ensures the delivery of his ejaculate, but may also serve to end male copulatory effort under circumstances when the female is, for example, suffering discomfort or pain, boredom, fatigue, or simply does not have enough time for the encounter to last longer. Females appear to be fully conscious of the positive effects that their copulatory vocalizations have on male self-esteem and a very high percentage reported using them for this purpose.
Further advantages of the female being able to manipulate the presence/absence/timing of the male orgasm may include the reduction of her risk of incurring physical damage from roughness, abrasion, and ensuing infection. One of the effects of female copulatory vocalizations may be to promote male self-esteem, which may strengthen the pair bond, decreases the risk of emotional infidelity and abandonment, resulting in continued access to resources and protection.
These data were remarkably consistent with findings reported in non-human primates, where, for example, in Barbary macaques (Macaca sylvanus) the likelihood of male ejaculation is related to the intensity and speed of female vocalizations during copulation
These data were consistent with the proposal that male ejaculation is influenced by female copulatory vocalizations rather than vice versa and points towards the evolutionary origin of human female vocalizations in the context in our polygynandrous past rather than our pseudo-monogamous present.
Thankfully the researchers ended the paper with that throwaway evolutionary explanation which gives me a good excuse the ignore the hard data and pretend it never happened.
http://mindhacks.com/2011/02/11/lets-hear-it-for-the-boy/
Just in case you had any self-esteem left ...