El oído medio

The middle ear is an air-filled chamber that lies behind the eardrum. Pressure in the middle ear changes to match air pressure outside of the eardrum. When inside and outside pressures are balanced, the eardrum is flexible and normal hearing is more likely. Problems happen when air pressure in the middle ear drops. This is often due to a block in the eustachian (u-STA-shun) tube, the narrow channel connecting the ear with the back of the throat.