we are using Jcaptcha framework for generating image and sound captcha.our application is working fine on tomcat server but when we ported the application to weblogic 9.1 it is showing some exception.The image captcha part is working fine in Weblogic but whenever we try to generate the sound captcha it is showing the exception IntializerError .The call for sound captcha goes to a servlet from where it is routed to soundGenerator class which calls another class GenricCaptchaService to get instance of GenericManageableCaptchaService class,here this exception is coming.
When second time i click the button for sound captcha the error comes is NoClassDefFoundError at the location where i have called for genericCaptcha.getinstance method.
 The error logs are:

java.lang.ExceptionInInitializerError
        at com.infosys.setlabs.captcha.sound.SoundGenerator.getCaptchaSound(SoundGenerator.java:47)
        at com.infosys.setlabs.captcha.servlet.SoundCaptchaServlet.doPost(SoundCaptchaServlet.java:29)
        at com.infosys.setlabs.captcha.servlet.SoundCaptchaServlet.doGet(SoundCaptchaServlet.java:63)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
        
java.lang.RuntimeException: unable to load voice :'kevin16'
        at com.octo.captcha.component.sound.wordtosound.FreeTTSWordToSound.<init>(FreeTTSWordToSound.java:70)
        at com.infosys.setlabs.captcha.sound.SoundCaptchaService.<clinit>(SoundCaptchaService.java:45)
        at com.infosys.setlabs.captcha.sound.SoundGenerator.getCaptchaSound(SoundGenerator.java:47)
        at com.infosys.setlabs.captcha.servlet.SoundCaptchaServlet.doPost(SoundCaptchaServlet.java:29)
        at com.infosys.setlabs.captcha.servlet.SoundCaptchaServlet.doGet(SoundCaptchaServlet.java:63)
        

The second time it is throwing this exception.
java.lang.NoClassDefFoundError: com/infosys/setlabs/captcha/sound/SoundCaptchaService
        at com.infosys.setlabs.captcha.sound.SoundGenerator.getCaptchaSound(SoundGenerator.java:47)
        at com.infosys.setlabs.captcha.servlet.SoundCaptchaServlet.doPost(SoundCaptchaServlet.java:29)
        at com.infosys.setlabs.captcha.servlet.SoundCaptchaServlet.doGet(SoundCaptchaServlet.java:63)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
    
I tried to check on net but couldn't find the solution.This is very critical to my project.so kindly repond to it as soon as possible.