a custom sound challenge*/
WordGenerator word = new DummyWordGenerator(captchaSession.trim());
SoundConfigurator configurator = new FreeTTSSoundConfigurator(voiceName, voicePackage, 1.0f, 100, 100);
WordToSound word2sound = new FreeTTSWordToSound(configurator, captchaSession.length(), captchaSession.length());
SoundCaptchaFactory factory = new SpellerSoundFactory(word, word2sound, new SpellerWordDecorator(";"));
SoundCaptcha tCaptcha = factory.getSoundCaptcha();
challenge = (AudioInputStream)tCaptcha.getChallenge();
}else{
//get the session id that will identify the generated captcha.
//the same id must be used to validate the response, the session id is a good candidate!