[zebproj]

The neat thing about this particular singing synthesizer is that it used a surprisingly sophisticated (especially for the 60s) physical model of the human vocal tract [1], and was perhaps the first use of physical modeling sound synthesis. Vowel shapes were obtained through physical measurements of an actual vocal tract via x-rays. In this case, they were Russian vowels, but were close enough for English.

While this particular kind of speech synthesis[2] isn't really used anymore, it's still fun to play around with. Pink Trombone [3] is a good example of a fun toy that uses a waveguide physical model, similar to the Kelly-Lochbaum model above. I've adapted some of the DSP in Pink Trombone a few times[4][5][6], and used it in some music[7] and projects[8]of mine.

For more in-depth information about specifically doing singing synthesis (as opposed to general speech synthesis) using waveguide physical models, Perry Cook's Dissertation [9] is still considered to be a seminal work. In the early 2000s, there were a handful of follow-ups to physically-based singing synthesis being done at CCRMA. Hui-Ling Lu's dissertation [10] on glottal source modelling for singing purposes comes to mind.

1: https://ccrma.stanford.edu/~jos/pasp/Singing_Kelly_Lochbaum_...

2: https://en.wikipedia.org/wiki/Articulatory_synthesis

3: https://dood.al/pinktrombone/

4: https://pbat.ch/proj/voc/

5: https://pbat.ch/sndkit/tract/

6: https://pbat.ch/sndkit/glottis/

7: https://soundcloud.com/patchlore/sets/looptober-2021

8: https://pbat.ch/wiki/vocshape/

9: https://www.cs.princeton.edu/~prc/SingingSynth.html

10: https://web.archive.org/web/20080725195347/http://ccrma-www....

[thrtythreeforty]

Another excellent, but quite dense, resource I've found helpful for implementing my own waveguide models is Physical Audio Signal Processing, a book available as a hard copy and online [1]. There are also an absolute ton of research papers on these topics which have failed to be summarized anywhere or cited outside the small circle of researchers, so there's a ton of institutional knowledge about physical modeling locked up in academic papers that isn't super accessible.

1: https://ccrma.stanford.edu/~jos/pasp/

[vidarh]

I've been fascinated by the simplicity of this since I ran into SAM (Software Automatic Mouth) on the C64, but never really taken the time to delve into it. Your links are an amazing resource...