Do you ever do this before you listen?

I have done it before for various reasons. Flying, colds etc. just never thought to do it before listening to my system. Makes perfect sense tho. 

rschrot......You are correct in your basic knowledge with the anatomy of the ear. However, that doesn't explain away the danger of someone puffing with a closed nose just to hear their music better.
Extreme pressure can cause damage to ear components. At what point does a person stop puffing to clear what may be an inherent hearing loss. Sure, momentary equalization would allow better hearing. But, there may be other reasons to investigate.
People may not be satisfied with performing the "hold your nose" technique and may try harder. Perhaps simply risking damage to the eardrum or perhaps worse. Besides the eardrum, there are ossicles in the middle ear. Most importantly, those ossicles act on the oval window...consider it an inner eardrum. Then vibrations are transmitted to the cilia (hairlike nerves) in the cochleas where the sound is transmitted to the brain. I could talk about the workings of hearing a lot longer.
In the end, simple ear popping is common and cures a simple situation. But, there are those who may take that to an extreme. Temporary hearing loss is one thing but I would caution listeners who would also take ear popping to the extreme.

I do all the time specially when I’m in the airplane during taking off and landing.

"In the end, simple ear popping is common and cures a simple situation. But, there are those who may take that to an extreme. Temporary hearing loss is one thing but I would caution listeners who would also take ear popping to the extreme."

Well hopefully no one will do this to the point that causes damage to their ears. That would make me feel horrible for bringing it up.

So please be careful if you try this technique. Seriously
Now I feel bad :(

Only professionals should do it on a closed course.