[Lewis Thomson (OP)]

Michael is looking for clarification on this question.

"If there was a horn centered on a a track would it exhibit the Doppler effect as does the oncoming train? If so would that mean sound could be a particle and a wave?"

What do you think? Leave your insights in the comments below...

[alancalverd]

The Doppler effect is entirely a function of waves, at least as far as sound is concerned, since sound is a series of pressure waves.

[Eternal Student]

Hi.

If there was a horn centered on a a track would it exhibit the Doppler effect as does the oncoming train?

   If the horn made a noise then the train will hear it at a different frequency when it approaches the horn.
   Similarly, if the train makes a noise then the horn would hear it at a different frequency as the train approaches.
   It also doesn't matter who was the thing that was moving.  The train can stay still while the horn was moving toward the train and the same thing would happen.

     Trains and horns don't usually have ears but for simplicity we'll say they hear the sound.   A pressure wave passes through their bit of space, which has a shifted frequency.

If so would that mean sound could be a particle and a wave?"

    Ummm....  No.    I'm not sure why you would think this follows as a consequence.

    However, there is some theory where sound can be considered to have particle-like properties and the name  Phonons  (instead of Photons) is used to describe these sound particles  or   quasi-particles.   This treatment of sound waves has some use and application in condensed matter physics.    See   https://en.wikipedia.org/wiki/Phonon

Best Wishes.