Can't hear or talk anything on Chatroulette, help me, please

Hi everybody, I have a problem with Chatroulette, 'cause, as title say, I can't hear or talk anything. First, Chatroulette doesn't have an own support, it says every issue must be treated here. Now, I'm having this problem on a K43E ASUS laptop, wich have and integrated microphone and webcam (I already checked  it and it goes ok, for example, in messenger), on Mozilla Firefox explorer (15.0.1) with last Flash Player version (I downloaded it yesterday); when I'm using Chatroulette I can enable both (as an option) but only webcam works, there's no way to talk, and more worrying, any sound (even from other programs, like iTunes, or webpages, like Youtube, or Chatroulette itself)!! I'd like to you guys help me out with this, to knowing if it's 'cause some configuration issue or whatever (I don't think it maybe a hardware problem), I want, at least, the sounds work.

Thank for helping

See you

PD: I'm not a native english speaker, so, excuse if message is not well written .