So these are actually two questions.
Changing voices:
MOVI 1.0 can change the voice from male to female with the command
recognizer.setVoiceGender(FEMALE_VOICE);
MOVI 1.1 will allow to switch between e-speak and SVOX Pico and allow to pass any command line parameter to these tools.
For example:
recognizer.setSynthesizer(SYNTH_ESPEAK,"-v+whisper");
will allow to have MOVI whisper or
recognizer.setSynthesizer(SYNTH_PICO,"-l=es-ES");
will make it speak Spanish.
More information can be found in the "SynthesizerControl" example.
Changing the output channel:
MOVI's output channel is practically mono. If you want the sound to go to two speakers that each can be switched on and off, I can think of an Arduino circuit to make that happen...
Hope that helps,
Gerald