There is a tube that connects the middle ear to your throat called the Eustachian tube. This tube helps to equalize pressure on both sides of the ear. Since the eardrum is a solid membrane and there is empty space behind the eardrum, there has to be a way to equalize the pressure or the eardrum would rupture due to the pressure. What your hearing is that pressure equalizing. The reason it only happens when you move your jaw or chew is because your Eustachian tube is inflamed meaning that with your jaw in normal position, the air isn't able to pass through and equalize the pressure. Things that can cause inflammation include current or recent head cold, sinus infection, and very commonly, allergies. Go to your Dr, steroid nasal sprays work very well in reducing inflammation in that tube and will alleviate your problem. As the inflammation gets worse you will start to notice your ears popping and a lot of pressure and eventually pain. So get it taken care of now before it gets to that point.
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