This video is truely amazing.
Watch the shockwave from bomb spreading at 340m/s against a tank. Insane.
And if this once happens to you, you should keep your mouth open.
It’ll indeed help let the pressure even out or escape from the blasts. The ear, nose, and throat are connected, so if you open your mouth a bit, your ears won’t pop as badly and it’ll help keep the pain and damage down if there’s continuous blasts near you because it’ll let the pressure escape quickly like through an open vessel.