Monday, September 22, 2008

Zooming in

We were talking last class about sample rates and bit depth, and I think Jim touched on the subject of time-stretching effects...

Even a short sound event of a few seconds can have a microcosm of sound information awaiting our discovery.  We've seen that certain sounds can take on new meanings when isolated and looped.  There is also sound content that can be exposed when a sound is sped up or slowed down.  The software available to us today can let us stretch or contract a sound source while preserving its pitch, in addition to letting us speed it up or slowing it down, as tape decks did.  Time stretching can produce digital artifacts which are probably regarded negatively in most cases; however, sometimes more extreme uses of digital processing can produce interesting new content.

Here is sample of a short two or three second piece of audio that I stretched to 19 seconds.  The original recording is of a radio voice actor saying the words, "America's natural fish supply."  The musical pitches present in speech can fly right by without our notice.  In this case, stretching the sound revealed a hidden melody, which, when looped, formed the basis of a short film soundtrack.  This was done last year in Audacity — Pro Tools also has time-stretching effects. I don't mean to jump the gun on the effects-processing topic, but, rather, to submit that nature can yield up richness on a microscopic level. Sometimes it's nice to zero in on the smaller things.

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