Paragraph on “Ears and Sound System” complete paragraph for Class 9, Class 10, Class 11 and Class 12
Ears and Sound System
Our ears not only allow us to hear sounds, thus preventing the world from becoming a silent one, but also act as organs of balance. They collect Alunds from the air and pass them to the brain in the form of nerve signals. Human beings can hear sounds within a certain wave length but animals like dolphins and bats can hear sounds of a much higher wavelength, which may not be picked up by the human ears. Human ears are located on both sides of the head and are divided into three parts i.e. the outer ear, the middle ear and the inner ear. The outer ear picks up the sound from the air, with the help of a flap called the ‘Auricle’, and sends them through the ear canal to the middle ear. The middle ear has a membrane or eardrum called ‘Tympanum’ which vibrates as the sound reaches it. The vibration of the eardrum causes three small bones called ‘Ossicles’ to vibrate and send the sensations to the inner ear. The main part of the inner ear is shaped like a snail shell, called the ‘Cochlea’. The cochlea contains a large number of microscopic hair cells, sound vibrations received from the middle ear cause the liquid to flow over these hairs thus causing them to vibrate. These vibrations are changed into nerve signals by the cochlea and passed on to the brain through a series of auditory nerves. The liquid in the cochlea also helps us in maintaining our balance because as we move our head from side to side, the fluid flows around thus letting the brain know the angle at which the body is located.
Not all animals have the capability of hearing, some of them, like fish, rely upon vibrations which are felt by lateral grooves on the sides of their bodies. Other creatures like dogs, rabbits etc, also have the capability to swivel their ears in the direction of the sound, this cannot be done by man. Ears arc a sensitive organ and they should not be injured or cleaned with a `harp object.