Granulating a sound file by manipulating the read pointer transforms the identity of the original source

Any granulator can generate a huge amount of derived material from a single sound file by manipulating the position, speed, and direction of the read pointer through the file. A slow backwards-scan granulation, especially combined with per-grain pitch shifting, filtering, and spatialization, changes the identity of the original sound while retaining its raw timbral content. At the extreme, reducing the duration of the grains has the inevitable effect of churning any source into broadband noise. This is the most direct practical entry point to granular sound design: rather than synthesizing grains from scratch, you scatter a read pointer across an existing recording and let grain size, direction and speed reshape it.

Examples

A slow backwards read-pointer scan over a vocal sample, with per-grain pitch and filter randomization, yields an unrecognizable evolving texture; shrinking grain duration toward a few milliseconds turns the same source into broadband noise.

Assessment

Take one sound file and produce two contrasting textures from it using only read-pointer position, speed and direction plus grain duration. Explain which control most changes the source’s identity.