Creating scene sounds

I've been reading Michael Ondaatje's The Conversations: Walter Murch and The Art of Editing Film and came across a very interesting passage the other day. Murch and Ondaatje are talking about hyperreal sounds: how sometimes recording a "real sound" just doesn't cut it for a film. For example, for Apocalypse Now, Murch needed cricket sounds for a scene. Murch knew that he wanted a "hallucinatory clarity," and he knew that going out and recording a field of crickets would be too ordinary for the scene. He needed something that was extraordinary — or, in his case, hyperreal. So, Murch went out and got close to one cricket and recorded it. Then, electronically, he multiplied the sound of that one cricket to make the sound of thousands of crickets, all in the same pitch, which gave it a "harmonic unity."

I think it's so interesting how much altering of sounds is done in film in order to give bring the audience in as much as possible. If you think about it, the aim of everyone involved in the film is to make it as real as possible for the audience so that they are able to feel captivated and engrossed by it; able to feel part of the world on screen. Weird, then, how, in order to get that sensation, sound designers have to manipulate real sounds or record "fake" sounds (ie. sounds created in a foley studio that weren't recorded during production). Nothing is ever as it seems, especially in the world of film.