During a livestream to support Operation Supply Drop 2015 Naughty Dog QA lead Trevor Stevens talked a bit about what kind of QA Testing is going on for Uncharted 4: A Thief's End.

Stevens mentioned that there are currently "well over thirty, forty-ish" internal testers working on the game,  and the studio is still hiring, with a goal of having about sixty testers

If you live in the Santa Monica area, and you're tempted to apply, Stevens explained that the studio isn't looking just for people who "play games."

He described the job as watching your favorite movie, but not from start to end. Instead you'd be watching the same five-second clip over and over and explain what you see wrong with it every single time. And then when it gets improved, you watch the same clip again and repeat the process.

According to Stevens there are times in which the QA team has "amazing amounts of fun," and other times in which it's really frustrating.

Sound Designer Robert Krekel also took part in the show. He's also currently working on Uncharted 4 and also worked on The Last of Us and Uncharted 3. 

Krekel gave some interesting information about his role at the studio, explaining that the team doesn't only try to give signature sounds for different weapons, but also how sound propagates through the environment, so you can tell if someone is in the next room or two doors over. They try to model it as close to reality as possible.

For creating sounds of weapons the team has the luxury of not having to stick too close to reality, but Krekel still tries to keep to the same caliber with the original recordings, but that's not always the case. The important thing is that the sound "feels right."

Krekel mentioned that his favorite sound he created for The Last of Us is the variable rifle. It didn't even take much iteration to get right. That's rare as it normally takes more tries in order to find an effect that sounds cool, feels right, and isn't too big or too small depending how powerful the gun is.

Currently he's working on Uncharted 4's Foley system (basically the reproduction of everyday sound effects, like the swishing of clothing  or footsteps), in order to make it "more dynamic and more subtle." Krekel is fine tuning the sounds made by Drake's feet, his jeans and the gear hanging off his belt to make them more subtle so that they dynamically change between when the character is moving slowly and when he's going faster and fighting, as if someone was making the sounds "in real time" through Drake.

He explained that he often "geeks out" on elements that most people won't notice, but that just make the game "feel right." According to Krekel if the sound feels right you often don't even notice it.

Incidentally, if you're considering applying as a tester to get your hands on Uncharted 4 before we all do, the specific career opportunity ad can be found here.