The external part of the ear is called external ear. This is the first part of the ear. It consists of three parts.
1. Pinna: The flat, flexible and skin-covered part located on both sides of the head is called pinna. It is funnel-shaped, hairy and composed of cartilage. Its length is 6-6.4 cm and width is 3 cm. It has a small and round hole. The eardrum consists of several cochlear muscles. Pinna cannot be moved because the muscles are not contractile. Because of this, to hear a sound well, the head along with the ear hole has to be turned towards the sound. Sound is transmitted to the external auditory meatus through the pinna.
2. Auditory Meatus: The narrow duct from the pinna to the tympanic membrane is called the external auditory meatus. It is a curved tunnel. Its outer two-thirds is made up of cartilage and the inner one-third is made up of bone. Its length is 2.5 cm and width is 0.7 cm. It contains wax glands and fine hairs. Through this the sound waves reach the tympanic membrane. Due to wax and hair, dust and germs cannot enter inside.
3. Tympenic Membrane: The oval and elastic membrane at the end of auditory meatus is called tympanic membrane. Its outer side is concave and inner side is convex. It separates the outer and inner ear. It has a diameter of 9 mm, thickness of 0.1 mm and weight of 14 mg. If this screen is damaged, it is not easily reconstructed. Through this the sound waves enter the middle ear.