- Your blank didn't change right away.
- Not until you fell asleep.

4 seconds sound clip from the Invasion of the Body Snatchers (1956) movie soundboard.

You can hear this line at 00:41:48.932 in the Blu-ray version of the movie.

Quote context

[...]

- Somebody or something wants this duplication to take place.

- But when they're finished what happens to our bodies?

- I don't know.

- When the process is complete probably the original is destroyed or disintegrates.

- No, wait!

- I'm sorry, but I take a dim view of watching my own destruction take place.

- There isn't any danger until they're completely formed. We learned that last night at your house.

- Your blank didn't change right away.

- Not until you fell asleep.

- When the change does take place do you suppose there's any difference?

- There must be.

- Wilma noticed it.

- So did little Jimmy.

- So did I. My father.

- That must be what he was doing in the cellar last night: placing one of these. I'm sorry.

- I felt something wrong, but I thought it was me because I'd been away for so long.

[...]