bla(h) bla(h) - normally with h... means "What you're saying is a waste of time me listening to - all I'm hearing is noise" = I don't want to hear it! I am ignoring you! (although I am recognising that you have spoken, I am telling you that I am not going to pay attention/listen to what you are saying!)
bullshit = that's not true, nonsense, rubbish/trash...