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Outer ear, collecting sound waves

Outer ear is the visible part of the ears, and its main function is to collect sound waves. When sound is generated, they travel through air and are collected by the pinna and led toward auditory canal and reach middle ear. Another key task of the outer ear is to protect the ear by producing earwax. The earwax is produced by the skin of auditory canal and protects the ear. The earwax protect the ears from infection; however, when the wax is solidified inside the ears it causes problem and pain and people are recommended not to clean ears by themselves as they might harm themselves. Outer ear canal is a duct of 2 or 3cm and capacity of about 1cm3 and leads to eardrum. Voice vibrations are transferred through air until they reach the eardrum. Sometimes man needs eyes.

 

Middle ear: useful vibrations

The main function of middle ear is to receive voice waves from the outer ear and convert them to vibrations. This is done by eardrum that separates outer ear from middle ear. The three small and delicate bones in the ear are called bones of the middle ear. Eardrum is a thin membrane that acts like a drum attached to the first bone of middle ear (hammer). Hammer bone is attached to another bone, which is the smallest bone in human body and called stapes.

Parts of the middle ear: skull, ear canal, pinna, elliptical window, hammer bone, stapes bone, anvil hammer, canal, auditory nerve, and Eustachian tube.

Hammer bone is attached to eardrum membrane and stapes is attached to elliptical window, which is 14 times smaller than eardrum.

 

Inner ear: initiation of neural stimulation

Voice waves are converted to vibrations and enter inner ear; then, the vibrations enter cochlear. Cochlear is a spiral small tube in inner ear and part of membrane labyrinth. The cochlear is filled with a liquid and its inner wall is covered with thousand thin hairs. When sound vibrations hit the liquid, the liquid starts to vibrate; different voices create different vibrations and in turn vibrate auditory hairs so that the stronger the vibration, the faster the hairs vibrate.