A voice and a saw wave, wired so the saw does the talking. Chop the voice into syllables and put them in any order, then detune the thing speaking them. Headphones recommended.
Everything you hear is synthesized or chopped in the browser: no audio framework, just Web Audio and two AudioWorklets. The engine is a plain TypeScript package (@mixpigeon/engine) that drops into any site, game or art piece. The instance on this page lives at window.mixpigeon.