I have often wondered if it would be possible to have the Many fans of a game actually Contribute to that game's release, and wouldn't it be neat if one of those ways could be by doing voiceovers for characters in the game.
I think anyone who has played Elder Scrolls or Fallout (or any game that has multiple voiced characters) can agree that hearing the voiceovers from the NPCs at first is neat, but after hearing the same voice used on the 15th NPC it gets kinda old. I do understand that each voice actor costs money, and developers do the best they can, but what if the Fanbase could be used to generate Some of those misc NPC voices.. Short script sets could be posted out with a set of general "type" guidelines (female, low pitch, energetic, blah blah) and then Fans, who have the means, could provide sound clips for those scripts (and consent to use those voices without compensation). They could then be reviewed, and then possibly incorporated into the game.
Of course, such a thing couldn't be done for the main characters, but using this for the filler quotes from non-primary NPCs would enhance the variety in the game's soundscape.

Perhaps there's not enough time to do such a thing, or it would be too much effort to sift through the throng of voices to find those that are useable, Maybe this is just a crazy thought, but why not suggest the insane from time to time

A large issue isn't number of people, but the sheer filesize required for them, on an aging medium where every byte counts.

Also, voice acting is nowhere near as easy as it seems, the vast swamps of crap would outnumber the potentially usable clips 1000:1.

It would require a lot more time than doing it the old-fashioned way.