> I read faster than I can listen to someone

That's just a matter of practice. Average reading speed is ~230 WPM, listening speed can easily reach 300 WPM (YMMV of course). Note that speaking speed is ~170 WPM. I'd wager you can easily reach 2-3x on most voiced content after a few weeks of practice.

Also note that audio processing is computationally much cheaper than video processing, which I don't think is just a coincidence.