FreePhone Online NO SOUND

Hi I Downloaded freephone online awhile ago and it was working fine .then I kept getting error messages so I uninstalled it and then reinstalled ,This is an updated version that apparently works well other than the fact that I cannot hear it
I know it works because I used it to dial my cell phone But I could not hear anything when I Speak into it I dialled it backfrom my cell and left my voice message and that worked perfectly I got the message in my email..Do you know how to fix this or what the problem could be ? the no sound is driving me crazy :cry