Vatican denies it.
From The Australian: Pope's blessing 'probably recorded' [February 07, 2005]:
"THE words of Pope John Paul II's Angelus blessing today were 'probably recorded' after his voice faltered when he started to deliver the traditional blessing from his hospital window, Italian media reported.
In an exercise designed to show the Pope was recovering from the severe breathing difficulties and throat infection that caused him to be hospitalised last week, the Vatican appears to have resorted to a tape as the pontiff seemed to choke on the first few words of his blessing.
TV station Sky Italia said in a report the Pope's brief blessing was 'probably recorded'.
There was no immediate response from the Vatican."