About the Ear and Hearing
Understanding Your Body
The ear has three parts: the outer ear, the middle ear, and the inner ear. The outer ear includes the part outside the head and the ear canal. The eardrum is a small circle of tissue about the size of a fingertip at the end of the ear canal. The middle ear is the space, usually filled with air, behind the eardrum. When a child has middle ear fluid, this is where it is found.
A small tube—the eustachian tube—connects the middle ear to the back of the nose. Three tiny bones (the malleus, incus, and stapes) connect the eardrum through the middle ear to the inner ear. The inner ear is further inside the head and is important for hearing and balance.
In a healthy ear, sound waves travel through the ear canal and make the eardrum move back and forth. This makes the three bones in the middle ear move. The movement of these bones sends sound waves across the middle ear to the inner ear.
The inner ear sends the sound messages to the brain. But if the middle ear has fluid in it, then the eardrum and the bones cannot move well. This could cause a child to have trouble hearing.