When I asked the computer to identify it, what I got was magma displacement.

4 seconds sound clip from the The Hunt for Red October movie soundboard.

You can hear this line at 00:52:27.633 in the Blu-ray version of the movie.

Quote context

[...]

- Martinez, get yourself a cup of coffee and have them send me up some tea.

- Aye, Captain. Messenger, get the captain a cup of tea.

- Captain. Sir, the moment that sub went silent and I thought I heard some singing, I heard something in the background real faint, and then, after all those subs took off, I caught it again, and I managed to get it on tape.

- I washed it through the computer a few times and I was able to isolate this sound.

(Magma displacement)

- When I asked the computer to identify it, what I got was magma displacement.

- You see, sir, the SAPS software was originally written to look for seismic events and I think when it gets confused, it kind of runs home to Mama.

- I'm not following you, Jonesy.

- Sir, I'm sorry. Listen to it at ten times speed.

(Submarine engine)

[...]