Just for the record, it's called "valsalva" or the valsalva maneuver. I became very familiar with it while flying Air Force jets (for 10 years of a 23 year career). I logged 2,300 hours in the cockpit and had to valsalva during every, single descent. The majority of folks "clear" (equalize the pressure) naturally or by just swallowing or jacking their jaw, but not me. I always appreciated the fact that the oxygen mask, which is mostly made of very hard plastic, has soft rubber spots (the size of a silver dollar or so) on both sides of the nose, which permit you to valsalva. Handy. As others have correctly noted, it will not hurt you if you do it gently and just enough to clear the pressure. Hard, fast, and violent are to be avoided. Like a minority, but still significant number of people, my ears are sensitive to changes in atmospheric pressure. My whole life, I've been unfailingly able to predict when the weather is going to turn from yucky to sunny by the increase in ear pressure (high pressure systems are often, but not always, associated with nice weather). As superpowers go, it ain't much, but it's something. Also, after a routine commercial flight, I'll wake up the next morning with a great deal of residual pressure in my ears and that will persist for about 24 hours or so.
The point has been made many times in many ways on these pages, but I'll reiterate it: we're all made a little differently. Not only do we hear things a bit differently, but our ears actually function a bit differently. So it should come as no surprise that one person's "crystal clear, bell-like perfect trebles" are another person's "shrill, tinny, overstated, fatiguing highs." It's one of the many things that makes our hobby interesting and fun; vive la difference. But back to the OP's question: I will valsalva every single time before (and sometimes during) a critical listening session. And wow, does it ever make a difference.
