I seem to recall that something like this was discussed a while back, but I can't find the thread.

Here's the issue with my diesel locos: in "head out" if I'm looking forward (up arrow) the sound is OK. If I'm loooking back (down arrow) it's OK too. But, if I start by looking forward and rotate my head around, when I'm looking directly out the side of the cab the sound gets very distorted.

Also, I created a passenger view of a brakeman (conductor these days) hanging off the right rear set of steps looking back and at the coupler area. Here too the sound is very distorted. Is this an anomaly of the use of stereo for some views and mono for others?