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

( train WHISTLE blows )
Westworld Season 2, Episode 6

and gave him that WHISTLE.
The Big Bang Theory Season 7, Episode 24

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

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