Funny you should mention. That's my non-verbal way of telling someone they're "hovering" around me while I'm working. I make that percolating Jetsons car hovering noise, then turn it into the sputtering driving sound as they leave.
My editor's taken to making the wookiee howl when minor things go wrong. Major things are usually met with an F-bomb, that's human nature... he's hard wired for that.
And lastly, there's an air makeup in the booth that makes a "whoop" sound (like a ~750ms frequency sweep) as it starts up. One of the shooters finally said "what the hell is that noise... is it time for the bonus round?" So we use a human-created version of that to signify any positive event. "Hey, I got a Playstation Portable!! *whooop*"
Grow old? Sure. Grow up? Never.