The Air Force said that all evidence indicates that the reports of unidentified flying objects are the result of... One... misinterpretation of various conventional objects.

11 seconds sound clip from the The Thing from Another World movie soundboard.

You can hear this line at 00:25:46 in the Blu-ray version of the movie.

Quote context

[...]

- Pat, I think we made a mistake.

- What do you mean?

- You ever read this? Department of Defense, Office of Public Information, Washington, D.C., December 27, 1949.

- Bulletin 629-49 regarding item 6,700, extract 75,131.

- The Air Force has discontinued investigating and evaluating reported flying saucers on the basis that there is no evidence.

- They'll probably make you a general for destroying evidence that they're wrong.

- The Air Force said that all evidence indicates that the reports of unidentified flying objects are the result of... One... misinterpretation of various conventional objects.

- Didn't look very conventional to me.

- Second... a mild form of mass hysteria...

- That'd be when General Fogarty got to shaking hands with that thing in the ice.

- What are the other reasons?

- Third... that they're jokes.

- What'd you say the number of that bulletin was?

- 629-49, item 6,700, extract 75,131.

- Oh... oh, that one.

[...]