"When the recording of a taped conversation began to play Wednesday at Barry Bonds's perjury trial, the jurors could barely hear what was being said.

The voices were garbled and the background noise was loud. But the gist of the conversation was understood. As jurors studied copies of the transcript, they furiously took notes. What they were hearing, prosecutors say, is strong evidence that Bonds used steroids.

On the tape, in which Bonds is mentioned once, a man was heard asking another about the problems of injecting steroids in the same location on the body every time. "