Remember when you used to play Sonic Heroes, and it sounded like Knuckles was saying a naughty word during his attacks? Well, it seems that was intentional – at least, that's what his voice actor says.
During a chat last month during Sac Gamers Expo 2024 (thanks, Sonic Stadium), former Sonic voice actors Ryan Drummond (Sonic), Scott Drier (Knuckles), and David Humphrey (Shadow) took part in a reunion panel for Sonic Heroes, which launched on PlayStation 2, GameCube, Xbox and Windows back in 2003.
Drier explains that during his recording session for the game, he recited the "shift, rock, yeah" piece of dialogue for Knuckles. During the session, members of Sonic Team asked him to make the "shift" part of the line as vague as possible so it would sound like a curse word.
Drier says he was told:
Would you feel comfortable making that 'f' of 'shift' as soft as you can? We want it to be 'shift', but we want people to wonder if you’re swearing.
So there you have it; you might have found this particular line amusing as a child, but it turns out it was (kinda) intentional from the start.