"But I am not really willing to accept your premise, because it may well be that the means of communications they have are of a kind that we do not know how to receive, and that they would not have the means of communicating with sufficiently powerful radio or optical signals. That is something which, technologically, is too difficult for them but they would have some other means we would not recognize." -- Thomas J. Gold, 'Communication with Extraterrestial Intelligence' (Sagan, ed)
I think they would be able to communicate with us since we use EM waves to transmit data and we are using optical transmission systems so they would be able to at least detect the patterns and formulate some response. They'd never get off of thier world without a strong understanding of the EM spectrum.
I just think that distance, time, and the violent nature of the universe in generalare the limiting factors.