Audio Sex Perception

I don’t suppose it would surprise anyone that straight men and women respond differently to men’s and women’s voices.  In fact, I think we would be surprised if we didn’t.  After all, straight men are attracted to women and their voices, and straight women are attracted to men and men’s voices.  But that’s only the obvious part.  They also tend to be different in their ability to perceive them, with both sexes responding stronger and faster to opposite sex voices.  They also differ in the amount of cognitive resources used in the task, the amount of effort applied.  Women use fewer resources than men… they are just better at it.

Now, before one says… OH, a sexually dimorphic difference in the brain!  Whoa!  Hold on!  That may not be true at all.  Other research into perception of other signals, ohh… such as emotional expressions have also shown sexually dimorphic difference in ability.  But in that case, we also know that wealth and power differences also show up.  Rich and/or powerful people are significantly and robustly less able to read emotions on other’s faces than poor and/or less socially privileged people.  Further, practice at reading people’s emotional expressions significantly improves this skill.  So, is that a built in, sexually dimorphic brain difference between men and women?  Or does is simply reflect that women, as a class, have less wealth, power, and privilege than men?  I’m betting on the latter.

And so it is with the amount of effort it takes to “read” one’s sex by listening to their voice.  Is this built in?  Or is it that women NEED to read voices better, just as they NEED to read faces better?  I’m betting on the latter.

Now we come to transwomen (MTF transsexuals).  In a study conducted in Germany, transsexuals seemed to be unique in some ways, like men in some, and like women in others.  One thing that they did find is that during fMRI scanning of the brains of transwomen, they showed that they were using very little effort to determine which sex a given speaker was, similar to women.  Interestingly, they analyzed both androphilic and gynephilic transwomen together and separately, though didn’t report them separately, instead they focused on testing pre-HRT and current HRT.  They found little difference between the two populations, androphilic vs. gynephilic and pre-HRT and HRT.  I’m not surprised by this.  In fact, it supports my hypothesis that this is NOT an innate sexually dimorphic trait, nor mediated by hormones, but the result of the social differences in privilege and experience / learning.  The two MTF populations have the same basic experiences regarding their own vocal history and needs, as the authors put it,

“Since we found no differences in accuracy between women and MtFs, decreased activation in MtFs might suggest that they need less effort to achieve levels of performance similar to women. This might be due to the fact that MtFs are more attuned to issues related to voice gender perception in everyday life.  … In line with the behavioral results, MtFs showed differences (compared to men and women) in neuronal response patterns with respect to male vs. female voices. Presumably, a different strategy is used in MtFs’ voice gender identification due to early processing differences. They also might more intensively examine their own and aspired vocal characteristics during gender alignment, resulting in a certain expertise. In this sense, attentional differences due to automatized processing could lead to less brain activation in MtFs.”

Reference:

Junger, J., Habel, U., Bröhr, S., Neulen, J., Neuschaefer-Rube, C., Birkholz, P., … Pauly, K. (2014). More than Just Two Sexes: The Neural Correlates of Voice Gender Perception in Gender Dysphoria.(11), e111672. doi:10.1371/journal.pone.0111672