
Is it a high-frequency WHISTLE?
The Big Bang Theory Season 2, Episode 10

They let me
blow the WHISTLE, Leonard.
The Big Bang Theory Season 5, Episode 23

Oh, danger WHISTLE.
The Big Bang Theory Season 8, Episode 19

- Can I WHISTLE?
- Don't be silly.
The Big Bang Theory Season 2, Episode 13

There are dozens of railroad crossings
you have to blow the WHISTLE for.
The Big Bang Theory Season 10, Episode 15