by CuteLittleFaery » May 14th, 2010, 9:54 pm
Sounds a bit implausible unless the male listener is already adept at convincingly effecting a woman's voice. You might be able to hypnotically train him to alter his voice, but it isn't going to magically happen right away.
A much simpler workaround might simply be a trigger that makes the listener perceive his own voice as female, regardless of how it actually sounds.