do you experience ringing of you ears when you are traveling from places with high altitude or mountain areas down to the city? why do you think someone will advise you to eat or munch candies or bubble gum during the travel ?
Yes, Swallowing, yawning, and even chewing a gum opens the eustachian tube and allows air to flow into or out of the middle ear. This helps equalize pressure on either side of the eardrum.
