Well, didn't you mention it?
4 seconds sound clip from the Desk Set (1957) movie soundboard.
You can hear this line at 00:07:46 in the Blu-ray version of the movie.
Quote context
[...]
- Cathy.
- Hello, Reference. Miss Saylor.
- Oh. It's for you, Mr. Sumner.
- Oh... How'd you know my name?
- Well, didn't you mention it?
- No.
- Oh.
- Yes?
- We've done a bit of juggling with our appointments.
[...]