WOW! Nice whistle.
Some trains really do emanate some good sounding horns and whistles. I am not a fan of the MTH whistle on the Imperial PRR K-4. It sounds like a tuba that was stuffed with a wet rag.
I actually adore the high-pitched whistle on the MTH PRR L-1 Mikado. It sounds similar to the one on the Hogwarts Express as seen in the Harry Potter films.
The "throatiest" whistle has to come from the massive Big Boy locomotive. It almost sounds like the deep bass "communication sounds" that came out of the mother ship in the movie "Close Encounters of the Third Kind"