Now, you'll note the wire running down to the creature's wrist. Dr. Blankfort keeps 1800 volts of electricity coursing through the body. More voltage, and it would die. Less, and it would awaken.

10 seconds sound clip from the 20 Million Miles to Earth (1957) movie soundboard.

You can hear this line at 01:01:10.526 in the Blu-ray version of the movie.

Quote context

[...]

- Sorry, old boy. My line. John? Get this.

- The size!

- Eight days ago, it was about this tall.

- How do you account for its astonishing rate of growth? Or is that normal on Venus?

- No, it isn't. The scientists believe that the Earth's atmosphere has upset its metabolic rate. The more air it breathes, the more tissue it builds, the bigger it gets.

- If you'll follow me, please.

- You've undoubtedly heard of Doctor Gerhard blankfort of Vienna, probably the world's top man in anesthesia. It's the doctor's job to keep the creature unconscious during the examination.

- Now, you'll note the wire running down to the creature's wrist. Dr. Blankfort keeps 1800 volts of electricity coursing through the body. More voltage, and it would die. Less, and it would awaken.

- Amazing. Utterly amazing.

- You can get a better look at the wrist connection this way.

- This is Doctor Koroku of the University of Tokyo. He's assisting Doctor Uhl.

- Another attempt to pry secrets from the creature, doctor?

[...]