> you quickly start to understand why they set the speech rate for their voice synthesizer to be so fast, it's almost unbearable navigating applications (and particularly lists) otherwise.

I imagine that for coding it also helps deal with the fundamental problem of an ephemeral stream rather than a persistent document that you can navigate visually in multiple dimensions. Working memory is limited, and getting more text in in a short period of time probably helps you work within that better. I also imagine that working with text via audio all the time gradually stretches and improves memory.

It's not the ephemeral stream that's the problem, it's the limited bandwidth.

You can show a lot more info on a screen than you can transmit through speech in a short period of time. That doesn't mean you read faster than you listen, just that sighted people essentially use their eyeballs as an "input device" to decide what information to look at.

If there's an object on the screen that you want to examine but that you don't need to click, you can just "navigate to it" with your eyeballs, without ever touching a mouse or keyboard. We don't have that luxury.

This means we need a much more efficient system for navigating what's on the screen, but that only gets you so far. Eventually, the easiest way to deal with this problem is just to increase the bandwidth of your channel, and you do that by increasing the speech rate.