Curiously enough, the dolphins had long known of the impending demolition of Earth, and had made many attempts to alert mankind to the danger, but their communications were misinterpreted as amusing attempts to punch footballs or whistle for titbits.
— The Hitchhiker’S Guide To The Galaxy Book (Peter Jones)
16 seconds sound clip from The Hitchhiker's Guide to the Galaxy (1981) - Episode 3 sitcom.
You can hear this line at 00:26:55.639 in the Blu-ray version of the episode.
Quote context
[...]
- My name? My name is Slartibartfast.
- It is an important and popular fact that things are not always what they seem.
- So they eventually gave up and left the Earth by their own means, shortly before the Vogans arrived.
- In fact, there was only one species on the planet more intelligent than dolphins.
[...]