A recorded sound file is stored, and will be played according to what MIDI numbers are activated by an input (such as the motion tracking program mentioned earlier) These numbers control pitch, a particular part of that file, or whatever you want really. Essentially, the file is changed from this:
to this - split into sections, of variable pitch. Therefore making non-linear noise, of any duration:
All of which can be done using open source software, or at the very least, minimum amount of cost. I should be putting up a list of all software used and/or code if any is used in future.
