>> they routinely use text to speech cranked up to illegible speeds.
> Note that this is not quite what I'm talking about.
Good point. I think I forgot to fully qualify that statement - while initially composing my reply I got completely distracted with TTS and forgot this was about altering speech to go faster. I realized and went back and edited it a couple minutes later, but didn't adjust it sufficiently.
> they routinely use text to speech cranked up to illegible speeds.
Note that this is not quite what I'm talking about. TTS is a slightly different problem since you're constructing the speech, and you can actually choose voice synthesizers that sound weird but remain intelligible at high speeds. On the other hand, trying to modify existing voice audio (with no text) for greater intelligibility at high speeds is a different problem.