Time-domain scrambling of audio signals

Scramble audio signals by shuffling short-time windows

These routines scramble an audio file by moving around short, overlapping windows within a local window. They can be used to create new versions of existing recordings that preserve the spectral content over longer time scales, but remove structure at shorter timescales. This can be useful e.g. for making speech unintelligible.

Routines are also included to shuffle Gammatone subbands independently, for further scrambling.

Code is also available from http://www.ee.columbia.edu/~dpwe/resources/matlab/scramble/

Includes Gammatone / ERB filtering routines lightly adapted from Malcolm Slaney's Auditory Toolbox,
http://cobweb.ecn.purdue.edu/~malcolm/interval/1998-010/