Time-Domain Pitch Synchronous Overlap and Add (TD-PSOLA) can modify the fundamental frequency and duration of speech signals, without affecting the segment identity – that is, without changing the formants. Normally, it’s an automatic algorithm, but here we do it the hard way – by hand!
If you want to follow-along, you will need Audacity and these materials (a zip file containing a set of Audacity projects for the various stages of the algorithm).
In the example in the video, I increased F0, but the side effect was to make the duration shorter. Try it yourself, but this time make versions of the word with
- increased F0, but the same duration as the original
- longer duration, and the same F0 as the original
This is the new version. Still under construction.