This seems to be much more the linguistically things are put together inflection along with facial expressions and handgesturs and some would throw in a lisp although I would not say that's requirement. As for me I know for hearing recordings of me self speaking, and from even what friends and coworkers say I do sound gay when I speak, how ever I don't lisp. (I went threw a few years of speech therapy when I was in elementary school to get read of the lisp I used to have)
If we are to go with the above definition of what the "gay accent" is, which is the definition that I will be using for now, then I would strongly suspect that the "accent" is alot more hardwired into the person then one might thing at first blush. First off what most people seem to pick up as part of the "gay accent" even in a deep "masculine voice" is that it flows in a more feminine which should not be way to surprising being that since has found that the brains of gay males are wired more similarly to females so it could be possible the speech patterns are also affected by this process Then their is the fact that its not uncommon at all for guys to develop the sort of gay speaking mannerisms before they even know or understand that they are gay let alone have any reay imersion in the gay community where they could be "pire pressured into picking up the "gay accent". That two leads one to believe that at least the speaking structer as well as the facial expression and hand gestestiors are things that to certain extents tend to be much more pre wired.
This is why I tend to resent it when any one says that being one way or another as a gay person is wrong, as what it impliess is that (unless the person is actuly facking) the inat scharacters of that person is wrong, but also their personality and how it is most comfortable for them to manifest them selves and their personality to the world. To do so is almost as bad in my book as when the straight community would tell them or any one that they ought not to be gay, and ought not to live their life how they see fit and how best makes them happy and makes them fell comfortable with them selves, as wells as inside their own skin. I think that part of the strength that those who fight against us have is that even on something as trivial this the community gets and starts pointing fingers at one another as whats wrong with the community, instead we need to just finally say "you know there's so many of us their are bound to be different flavors the gay mannerisms and non of them are wrong" and move on from there.
As always thanks for reading, comments and freedbac are always welcome. :-)