I'm not even sure how this was even a power. Sure, Superman learned how to throw his voice. Even if he could throw it really far and really convincingly, how is that super-ventriloquism, as opposed to just ventriloquism? Do things become "super" just because Superman is doing them? Or does he need to be doing them in some super fashion, like really fast or at a really long distance? Inquiring minds
It'd be easy to scoff at a power like this, to dismiss it as some relic of the Silver Age. And we could do just that, sweeping it under the same rug where we swept Beppo the Super-Monkey. Unfortunately, it's not that simple. Take a look at this panel from the 2005 "The Question" miniseries.
That's Superman, as you may have guessed, explaining to the Question how he's able to talk to him from across town. Sure, they dress it up in some fancy jargon, but it's still very obviously super-ventriloquism. In fact, it's worse, because it's the idiotic power of super-ventriloquism dressed up in even more idiotic jumbled science. It's been awhile since I did acoustics, but I'm pretty sure sound doesn't work that way.
The worst part is that it's utterly unnecessary for Superman to have a power that allows him to communicate at large distances. Strangely enough, we all have that capability, without the need for superpowers--just radios, walkie-talkies, cell phones, and so on. Was it really that much easier for Superman to figure out a way to laser-focus his speech at the Question (and hope no one got in the way of the sound waves) than to find out his phone number or commlink frequency or something? Or to contact J'onn and arrange a telepathic link? Really?
Granted, this miniseries was bizarre and confusing all around, and seems to have been largely (if not entirely) forgotten. Even so, the fact that someone has used super-ventriloquism non-ironically in the last five years is cause for alarm and despair. We must all band together to make sure that the idiocy of super-ventriloquism never darkens the page of a Superman comic again.