If you jerk this cord on either side, carbon dioxide will be released from the capsules and the vest will inflate immediately.
9 seconds sound clip from the The High and the Mighty (1954) movie soundboard.
You can hear this line at 01:30:20 in the DVD version of the movie.
Quote context
[...]
- I've never said it before, and probably you'll never want me to say it again.
- What else is on your twisted little mind, Lillian?
- I'm in love with you, Gustave. I guess I always have been.
- And then you tie the ribbons like this.
- These preservers are not inflated now.
- No, Tommy, no. We've not lost an airplane.
[...]