And in Wayne Manor, stately residents of millionaire socialite Bruce Wayne and his young ward Dick Grayson, whom we just saw at school.

13 seconds sound clip from Batman (1966) - The Joker Goes to School (S1E15) TV Series.

You can hear this line at 00:02:40 in the Blu-ray version of the movie.

Quote context

[...]

- This smells like an opening gambit of his.

- That devil!

- But how can we be sure?

- We can't. Not yet.

- But if it's The Joker we're facing then his plot is aimed at Gotham City youth. We can't wait to be sure.

- Now this if there ever was one is a case for our unknown friend behind the mask.

- And in Wayne Manor, stately residents of millionaire socialite Bruce Wayne and his young ward Dick Grayson, whom we just saw at school.

- Please, Bruce, I beg you. Accept the proposal. Run for mayor.

- It's funny. They come to you with the same offer every two years. You'd think they'd get it through their heads you're not interested.

- I'm afraid she's right.

- You see, the good works of my Wayne Foundation require that I stay above the brawl of politics.

[...]