A ventriloquist? That is remarkable. You didn't even move a muscle.
7 seconds sound clip from the Mister Ed movie soundboard.
You can hear this line at 00:19:18 in the DVD version of the movie.
Quote context
[...]
- Actually, he's not such a bad...
- I don't want to rush you, but have you made any decision on the plans?
- But-But the horse. I heard it... talking?
- That wasn't the horse. I'm a ventriloquist.
- A ventriloquist? That is remarkable. You didn't even move a muscle.
- Would you believe it if I were to tell you the horse actually talks?
- I've been a ventriloquist for years.
- Let me see you do that just once more while I'm watching you closely.
[...]