When I was mixing the film, Francis [Ford Coppola] was off in Godfather II, shooting in New York. And I was mixing the film, but in the back of my mind, thinking always, 'Oh, how can we help this process?' And then out of the blue, I remembered a recording that I had made with Fred Forest and Cindy Williams, who played the couple in The Conversation. And I'd recorded a wild track, a separate track of them saying the conversation. And they and I went out with a Nagra, a tape recorder, to another park in San Francisco, but in a residential area where there was no noise or interference. And I just... they just walked around the park and I walked in front of them recording the conversation. So they said their lines and I recorded it with them actually walking, so you get the effort of them moving, so it doesn't sound artificial.

On the third take Fred said instead of 'He'd kill us if he had the chance', he said, 'He'd kill us if he had the chance.' So the emphasis was different, and I remember noting in my notebook: the third take is the wrong reading of the line. But in the middle of mixing the line, I thought, I'm going to find that reading, where is that reading? And so I dug around in the old tapes and came up with this third take. And I transferred that and put it in the film, at the very end of the film when Harry is realising that those two kids are still alive and they've taken over the business. And the Robert Duvall character is dead, seemingly in an accident. What's going on? And in the middle of all that, the line gets replayed, 'He'd kill us if he had the chance', which implies, therefore, 'We have to kill him.' And you don't even know who he really is or what their relationship is with him, that's all deliberately undernourished plot information. Is she his wife? Maybe. She could be his daughter. We just don't know, you know? And that's a deliberate strategy on Francis's part.

Anyway, I'd mix that in and flew to New York with this version of the film, and played the mix for Francis. And I prepared Francis ahead of time and I said, 'I, you know, changed the rules here at the end.' And we had this different reading of the line, and at the end he said, 'No, I like it, leave it in.' Now, he says, 'Well, we should have kept it the way it is.' But you know, that's thinking after the fact. At the time, it seemed like a good decision, and you know, I think it breaks the rules in a sense, because it isn't exactly the same conversation played over and over again, there is a shift. But it addresses this subjective nature of the single point of view. And by implication, it seems to say Harry Caul wanted them to be innocent, so he chose to hear it with a certain inflection, whereas it actually had another inflection. But you know, I can't go too far down that path without running up against some contradictions. But that's the story anyway, behind that process.