The cabin pressure in an airplane changes at take off. But it changes more during decent. On a recent flight I was thirstier than normal. I heard the water bottle pop with the air pressure change.
As disturbing as it was, it was also fascinating. I have always been told to chew gum. Evidently the chewing process helps to readjust the air within our body/head.
It is like twisting the top off from the water bottle which then allows the air inside the bottle to equal out. What was interesting and got me thinking was how much the bottle caved in. We have hard heads.