But he merely sat there, puffing at his cigar and regarding me with a smug grin. And I knew it was hopeless.

9 seconds sound clip from the Leiningen Versus the Ants (1948) classic radio play.

You can hear this line at 00:03:24 in the radio play.

Quote context

[...]

- But can't I make you understand...?

- I think it is you who do not understand.

- In the three years I've been here, I've met and defeated more than one catastrophe: flood, drought, a plague... events which caused many of my neighbors to flee for their lives.

- All my life, I have lived with one creed: The human brain needs only to become fully aware of its powers to conquer even the elements.

- Your obstinacy is endangering not only your own life, but the lives of your workers and their families.

- You don't know these ants! I tell you, you don't know these ants!

- But he merely sat there, puffing at his cigar and regarding me with a smug grin. And I knew it was hopeless.

- As I boarded my launch and cast off, I realized I'd never met a man like that.

- And I could not help wondering about the strange look in the Commissioner's eyes as he boarded his launch and cast off.

- Undoubtedly, he thought me insane. Well, he would have not been the first to think so.

- But I knew my own powers. I was sure of myself.

[...]