We are very casual in being able to hear properly as it happens effortlessly and automatically. In situations when we have stuffed up ears because of head cold, allergy or sinus condition it is more miraculous that we hear and take things for granted. In fact hearing ability and interpretation of sounds is a complex system that is perfect and works well. Permanent damage to any part of the process leaves one deaf in one or both ears. It is daily occurence attested by millions of people suffering from deafness and hearing loss.
The system
Three parts- the outer, middle and inner ear constitute the ear. Sound waves enter the outer ear and reach the middle year through the canal. The eardrum there converts the waves into vibrations felt by the tiny bones. These magnify the vibrations and send them to the fluid of the inner ear. The fluid of the cochlea contains hair cells. The hair cells move to the vibrating fluid. This change produces nerve impulses which electrical impulses go to the brain for interpretation. Damage to any of these brittle processing parts results in permanent deafness and hearing loss
Perfect formation of all parts makes the system work. Congenital defects in any significant part makes one deaf and lose hearing. Significant circumference of the ear canal, a misshapen cochlea, a malformed outer ear or any important change from the norm brings in diminished hearing ability. Where the problems cannot be corrected modern science can repair some accessible pars of the ear and provide treatment and training. Genetic disorders cause hearing loss slowly but steadily. Injuries to the ear damage ossicles viz hammer, anvil and stirrup. Ear drum can be damaged, by sudden very loud noise, permanently. Repeated exposure to local noise, does the same. Measles or meningitis may cause deafness or hearing loss. Ear was, infection, tumors are dangerous to hearing. Above all old age causes loss of hearing. We need not feel hopeless and can evade deafness and hearing loss by proper care and precaution.
[tags]Auditory Nerve, Measles, Tumors[/tags]