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2. WHAT IS HEARING: Sound waves travelling through the air reach the outer ear (pinna), which is the visible part of the ear. Through ear canal, they are further transferred from the piina to the middle ear. The middle ear consists of thin layer of tissue called - Eardrum and three very small bones called ossicles. When the waves reach the Eardrum, they make it vibrate and the vibration is amplified and transferred further inside of the ear by the ossicle bones. Deep inside the ear is the inner ear, which consists of cochlea (snail-shaped chamber). Inside of the cochlea is covered with large numbers of small hair cells and the whole chamber is filled with fluid. The sound waves, which were transferred to vibrations travel through the cochlea and transferred into electric nervous impulses by the small hair cells. Next, the electric impulses are carried to the brain b the auditory nerve connecting the ear with the auditory centres in the brain. |