Was Voldemort able to hear the entire prophecy?

No. The only people who knew the entire prophecy as of the beginning of book six were Dumbledore and Harry, who later told Ron and Hermione.

"Then you will have seen that there have been not so much leaks as floods concerning your adventure in the Hall of Prophecy?" "Yes," said Harry again. "And now everyone knows that I'm the one-" "No, they do not," interrupted Dumbledore. "There are only two people in the whole world who know the full contents of the prophecy made about you and Lord Voldemort, and they are both standing in this smelly, spidery broom shed. It is true, however, that many have guessed, correctly, that Voldemort sent his Death Eaters to steal a prophecy, and that the prophecy concerned you. "Now, I think I am correct in saying that you have not told anybody that you know what the prophecy said?" "No," said Harry. "A wise decision, on the whole," said Dumbledore. "Although I think you ought to relax it in favor of your friends, Mr. Ronald Weasley and Miss Hermione Granger. Yes," he continued, when Harry looked startled, "I think they ought to know. You do them a disservice by not confiding something this important to them."

From Voldemort's perspective, there is no way for him to retrieve the prophecy; he doesn't know that Harry knows it, and he has no intention to try and get it from Dumbledore.