The other thing that struck me was that I had spent my teenage years working with sound and then I had put sound aside as a... Something that I did when I was a kid and now I had to get serious. Now I was in film and of course, intellectually, I knew films had sound because actors talk and there are sound effects and everything but I had no idea, really, how this happened. How did it work? And if the teachers had pulled me aside and said, 'Walter, we have to tell you something about film sound which is that film sound is recorded at the time of shooting and it's embedded in the film, in some mysterious way, and we cannot change it later. So whatever gets recorded at the time, that's it. So if you want a sound effect, you have to make it at the time of shooting'. Of course, this was absurd in retrospect but I was innocent and if somebody had told me that, I would have thought, well that's a shame because I've seen how flexible sound is with what I had been doing with my tape recording but I guess, for some mysterious reason, film can't do that.

Of course, what I discovered was exactly the opposite; that everything that you do with film sound is identical to the kind of stuff that I was doing as a 12-year-old and it, in fact, is quite complicated how sound gets onto film. It... Especially then, you had to record it on a separate medium, you had to make sure that it was in sync, you had to maintain that sync and then of course, you had to add everything else that was not recorded at the time like sound effects and of course, music. And blending all of these things together into something that feels organic and of a piece, even though it's constructed kind of like a Frankenstein's monster, out of all these bits and pieces, is a real technical and artistic challenge which is one of the things that have defined the rest of my creative life in film. Has been dedicated to that process but I entered that as a relative innocent and it was only in film school that I saw these two interests really coming together. My 10-year-old, 12-year-old interest in sound and my newly ignited interest in cinema that really took hold when I was studying romance languages in Paris in the early 1960s.