Subject: How does testosterone affect voice pitch in adult males?

I have searched your site and found a couple replies that discussed adult vocal 
 development, but I specifically want to know how TESTOSTERONE affects male 
vocal pitch AFTER puberty is complete.  (e.g. I have read that testosterone can 
influence vocal cord tension)  I hypothesize that any individual adult male 
(i.e. with throat structure maturely developed) will have fluctuations in vocal 
pitch correlated with testosterone levels (due to physiological effects of the 
hormone, not psychological ones).  Can anyone corroborate this?  Any literature 
references would be tremendously appreciated for my graduate research!! :)

Thank you much for your time.
[NOTE: I see this topic as belonging well to either anatomy or medicine]

Re: How does testosterone affect voice pitch in adult males?