The outer ear is the visible part of the ear and it consists of the pinna (the auricle) and the ear canal. The pinna collects sound waves and funnels them into the ear canal. The ear canal is a tube that leads from the pinna to the middle ear. It is lined with tiny hairs and glands that produce earwax. The earwax helps to protect the ear canal from infection and foreign objects.
The middle ear
The middle ear is a small, air-filled cavity located behind the eardrum. It contains three small bones called the malleus, incus, and stapes. These bones are connected to the eardrum and to the inner ear. When sound waves hit the eardrum, it vibrates and causes the bones in the middle ear to vibrate. These vibrations are amplified and transmitted to the inner ear.
The inner ear
The inner ear is a complex structure located deep within the temporal bone. It consists of two main parts: the cochlea and the vestibular system.
* The cochlea is a spiral-shaped tube that is filled with fluid. It contains hair cells that are sensitive to sound waves. When the vibrations from the middle ear reach the cochlea, they cause the fluid to move and the hair cells to vibrate. This creates electrical signals that are sent to the brain. The brain interprets these signals as sound.
* The vestibular system is responsible for balance. It consists of three semicircular canals and two otolith organs. The semicircular canals are filled with fluid and they sense the rotation of the head. The otolith organs sense gravity and linear acceleration.