Organ of hearing people, exactly the same way as any other substance, provides the perception of sound vibration environment. Man is able to determine the direction of sound with its source, which gives him to orient in the environment, to distinguish between high tone and the power of sound vibrations. We hear because our ears respond to the smallest changes in air pressure, they make waves sound vibrations into electrical oscillations and transmit to the brain. Volume - is the energy level of sound is measured in decibels (dB). A whisper is about 15db, and the noise streets - about 90dB. The noise or sound levels are above 100 dB can be unbearable to the ear man, so the noise of the order of 140db (for example, the sound of jet engines during take-off) may be painful to the human ear and damage the eardrum. The majority of the population of our planet's acuity of hearing is dulled with age, this is because moving internal organs of the auditory apparatus of the person losing their mobility. Besides various kind of infection and common cold can permanently damage the internal structure of the human ear, so jokes and engage in self-treatment in such cases is extremely contraindicated, should be immediately see a doctor. The cause of certain types of deafness is damage of such a body as the inner ear or, in other words, the auditory nerve. The deterioration of hearing ability person may also be caused by a constant or frequent noise influence (eg work in a noisy workplace), or sharp and very loud bursts of sound vibrations. We must also carefully use all sorts of music devices such as stereo-players, because the excessive volume of acoustic waves can be similarly cause deafness. Indispensable means "struggle" hard of hearing in our mundane everyday life are a variety of auditory devices, the range and variety which grows with each passing day, thanks to modern advances in science and technology. Hearing aids now even pick up of three children with congenital hearing defects, because if the time to determine the disease - children grow up to full health, can complete a simple school and institution. The rumor was given to man by nature and is a wonderful ability, which should be properly protected, observing the rules of personal hygiene and at the slightest manifestations of deafness to see a doctor. This the concept of medicine is far from powerless.