Not a bother at all, though after this we should take it to a thread in the
Sound Science Forum. Feel free to tag me there.
Atmospheric pressure likely has a measurable influence on hearing, but I doubt it is even remotely significant. If it were, you would also be able to hear differences resulting from low/high pressure fronts due to weather or pressure changes due to temperature. Moreover, there so many of those tiny factors affecting hearing in insubstantial ways, that atmospheric changes are probably going to be balanced out by other factors. Things like time of day, mood, physical health, smoking, hypertension, age, fatigue, body position all have much larger impacts on sound anyway. And even those are typically less impactful than things like headphone position, pad condition, or fit. In short, there are a thousand factors affecting sound and it be utterly ridiculous for someone to say something like, "Of course you didn't like these headphones
in Miami! But, you should try them in Denver!" Although, I'm sure you can find someone who's made that claim...