ttslib is a processing wrapper for the freetts library with two new speak methods, that allow to choose which speaker the text should be coming from
CODE
tts.speak( “I am in the center” );
tts.speakLeft( “I am on the left” );
tts.speakRight( “I am on the right” );
The library can be downloaded at
http://www.local-guru.net/blog/pages/ttslib
Examples of text to speech
1st example: using TMP36 and text to speech library to tell the temperature
Arduino port identification using Processing
Another more simple example
import guru.ttslib.*;
TTS tts;
void setup() {
  size(100,100);
  smooth();
  tts = new TTS();
}
void draw() {
  background(255);
  fill(255);
  ellipse( 35, 30, 25, 35 );
  ellipse( 65, 30, 25, 35 );
  fill(0);
  ellipse( 40, 35, 10, 10 );
  ellipse( 60, 35, 10, 10 );
  noFill();
  arc(50,50,50,50,0,PI);
}
void mousePressed() {
  tts.speak(“Hi! I am a speaking Processing sketch”);
}
Audio images