- Goddamn, are you kidding?
- No, of course I'm not kidding. Do I sound like I'm kidding?

6 seconds sound clip from the Ferris Bueller's Day Off movie soundboard.

You can hear this line at 00:12:50 in the Blu-ray version of the movie.

Quote context

[...]

- This guy in my biology class said that if Ferris dies, he's giving his eyes to Stevie Wonder. He's such a sweetie. Got to go.

- Hi, Jeanie.

- Shut up.

- Please, do not yank my cord on this. How desperate is the situation?

- Well, did you see Alien? When that creature was in that guy's stomach? It kind of feels like that.

- Freshmen.

- Goddamn, are you kidding?

- No, of course I'm not kidding. Do I sound like I'm kidding?

- Who's he talking to?

- Ferris Bueller, do you know him?

- Yeah. He's getting me out of summer school.

- We appreciate you letting us know how you're doing. We've got to buzz. Keep a good thought, dude.

- Thanks.

- Shit. I hope he doesn't die. I can't handle summer school.

- Wait a minute, give me somebody else.

- Yeah, sure, hold on.

[...]