We hear a number of sounds every day. Some are pleasant while others are not. Do you know how our ear is able to differentiate and hear these sounds? On the basis of its structure, the human ear can be divided into three parts — external, middle and internal. Anything producing sound first vibrates. These vibrations set up a motion of sound waves in the medium through which the sound reaches our ear. The external ear has large surface and can receive a number of sound waves at the same time. When the sound waves hit the external ear, they are transmitted to the middle ear through a pipe. The middle part has the ear drum, which starts vibrating when these sound waves hit it. Just behind the ear drum there are three small bones called hummer, anvil and stirrup. As the ear drum vibrates, these bones also start vibrating. These vibrations are then transmitted to the cochlea. The cochlea is the part of the inner ear, which acts like a spring. It is surrounded by a fluid. The fluid contains the nerve endings. Due to the vibrations of cochlea the fluid also starts vibrating and this activates the nerve endings. The activation of the nerve endings produce impulses which are taken to the brain by the auditory nerve and we hear the sound. Our ears can detect both feeble and intense sounds with frequencies ranging from 20 hertz to 20,000 hertz. In order to keep the ears healthy, it is essential to clean them regularly. A waxy substance is produced in the ear, which gets deposited on the ear drum if it is not cleaned. If this wax accumulates then it can lead to deafness. Therefore, we should take care of our ears and consult the ENT experts as soon as there is trouble in the ears.