Nobody else has mentioned anything along these lines so I'll do so.
If you haven't talked to the blind community about this sort of thing already I would strongly recommend doing so as they'll be able to rapidly point you at the bleeding edge of what currently exists - they routinely use text to speech cranked up to illegible speeds.
(I also heard of one guy who would listen to TTS from his computer with one ear, while using his other ear to hold a phone conversation. I believe I read this in Thunder Dog: The True Story of a Blind Man, His Guide Dog, and the Triumph of Trust (978-1400204724 / 1400204720).)
The second reason I suggest this is that the blind community is a dense populus of users who use systems like this as part of their everyday lives, so if you aimed such a system at them the feedback quality would be extremely high and allow for ridiculously fast iteration times and a great product. High-speed speech (TTS in particular) is a genuine technology hole/need.
Great comment, thanks. Agreed that blind users would be at cutting edge of this and provide the most useful feedback.
> 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.
>> 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.
If you haven't talked to the blind community about this sort of thing already I would strongly recommend doing so as they'll be able to rapidly point you at the bleeding edge of what currently exists - they routinely use text to speech cranked up to illegible speeds.
(I also heard of one guy who would listen to TTS from his computer with one ear, while using his other ear to hold a phone conversation. I believe I read this in Thunder Dog: The True Story of a Blind Man, His Guide Dog, and the Triumph of Trust (978-1400204724 / 1400204720).)
The second reason I suggest this is that the blind community is a dense populus of users who use systems like this as part of their everyday lives, so if you aimed such a system at them the feedback quality would be extremely high and allow for ridiculously fast iteration times and a great product. High-speed speech (TTS in particular) is a genuine technology hole/need.