Available voices with HTTP Speak

Hi All,

I managed to get the sample code working on my Win8/Metro app, this is a great service to provide to developers :)  I've noticed that the TTS that comes back is rendered with a female voice.  Glancing through the documentation I didn't see a means to alter the voice.  Is this supported?  My application would stand to benefit from at least one male voice.  I've had to turn to other online speech services in the past due to lack of onboard speech support in WinPhone so I hope I can do it all with Translator.

Thanks

Rob