Did the horn in Movie 3 sound the same as the horn in Movie 1 or Movie 2?

How about the horn in Movie 4? Is it more like Movie 1 or Movie 2?

Based on prior experience--such as honking horns you have heard or ambulances that have driven by you--you were probably able to intuitively answer most of the questions posed to you thus far.

This is good news. It means you're well on your way to becoming an expert on the phenomenon called the Doppler Effect.