- Listen to the sounds.
- Hunting calls, mostly. Animals out for the kill.
- Some of them are cries of fear, like people who whistle in the dark.

11 seconds sound clip from the Creature from the Black Lagoon (1954) movie soundboard.

You can hear this line at 00:55:31.565 in the Blu-ray version of the movie.

Quote context

[...]

- Don't be long, David.

- You better get some rest.

- Hi. I thought I'd come up and get some air.

- What do you suppose is taking them so long?

- David's very thorough.

- But shouldn't you be resting, Kay?

- I couldn't sleep.

- Listen to the sounds.

- Hunting calls, mostly. Animals out for the kill.

- Some of them are cries of fear, like people who whistle in the dark.

- I'm not exactly blind. You're worried about what's happened between Mark and David.

- But once you admit the simple fact that you're in love, which you have, then it becomes a good idea to be the scientist about it.

- It's not as easy as that.

- Why not?

- If it weren't for Mark Williams, I wouldn't have my work or even a job.

[...]