Ear pressure in car

So, whenever I roll down a window in my car I almost immediately feel a weird pressure in my ears, and it goes away if I open up the parallel window. What causes this? I assume that is has something to do with the variant air pressure, but it would be nice to have a more detailed answer.

Just a guess, but air pressure could be building from air being forced into the car, but not having a ready exit. Both windows open would allow both entry and exit for the air, lowering the effective air pressure.

I believe it’s because with one window open, your car is acting as a Helmholtz resonator. This is what causes the low pitch sound you hear when you blow across the top of a bottle. Your car is much larger, so the frequency is very low, below the range of your hearing.

Maybe look at the Wikipedia page on Infrasound. From there

I can verify this effect, but for me only if a roll down one of the back windows and none of the front. I hear a very distinctive “womp womp womp” and estimating the frequency would put it somewhere at around 10Hz I’d imagine. This occurs inside my ears and is very disorienting and unpleasant.

I have precisely the same experience that drewtoo99 does when I have a back window open, but not one of the front ones. If I just have a front window open, I don’t experience the phenomenon. It’s distinctly uncomfortable, and I’ve wondered what it is about the design of my car that makes this occur. I’ve thought about starting a thread on this very subject, but I’d never gotten around to it. Thanks for the links, Zenbeam, that was interesting and informative.