Hi Craig,
To change the voices so that you have a Male Pilot and a Female ATC do the following.
In X-Plane go to Resources/ default scenery/default atc/voices/ in here you will find two folders.
1. default.
2. default pilot.
Rename default to default pilot.
Rename default pilot to default.
Then reload X-Plane and you will have a Male Pilot and a Female ATC.
Cap't Kev
X-Plane Addicted.