I just released a new version of my processing freetts wrapper.
In this version the pitch of the voice can be altered by using
tts.setPitch( 1000 ); // set the base frequency to 1000 hertz tts.setPitchShift( 1.2 ); // how much should the pich change over time? tts.setPitchRange(100); // in this example the pitch will vary between 1000 and 1100 hertz
Go to the ttslib project page and download a copy. Install as unsual by unzipping it into your sketchbook/libraries Folder.
ttslib installation via the processing PDE
Animator Library - 2nd Alpha version
Project-Page for Animator-library
Using Mbrola-Voices with the Processing ttslib