I think the sound also mimics the flange squeal that frequently happens with real trains from metal wheels running on metal tracks, especially on curves.
Although it can become annoying, I'm guessing most people enjoy the prototypical sounds rather than just silently running a train - at least I do.
Not sure, but if you can operate your engine with Bluetooth using the app, there may be a way to at least lower the volume rather than having to shut it off completely.
