Human Deafness - Causes Of Deafness in Humans

Like any other organ in the human body, the functioning of the ear is also very complex. The parts of the ear are very delicate and help to facilitate the proper functioning of this sensory organ. Apart from receiving sound, the ears also carry out the function of balancing the body. Human deafness is related to the inability of the ear to detect and understand sound. It can be partial or complete, and the former is more often referred to as hearing loss, rather than deafness. Some people are born with this condition, whereas some others develop deafness with age, due to various reasons. According to these reasons, deafness is classified into three groups.

Types of Human Deafness

Deafness in humans can be caused by a number of reasons, based on which the deafness is categorized. The three types of deafness are conductive, sensorineural and mixed. In case of conductive deafness, an impairment to the outer or middle ear prevents the sound from reaching the inner ear, which results in deafness. The impairment can be in the form of mild obstructions like excess ear wax, ear infection, etc. It can also be due to severe impairment like otosclerosis, where the abnormal growth of the middle ear bone blocks the passage of sound. However, most cases of conductive hearing loss can be cured by medications or surgery.

Unlike the former, sensorineural hearing loss is almost permanent in nature and is the result of a disorder of the inner ear or auditory nerve. The causes for this type of deafness include heredity, diseases, exposure to excess noise or certain chemicals, certain medications, old age, etc. The third type of hearing loss is a combination of both the former types. Let us now take a look at the various causes of deafness and hearing loss.

What are the Causes of Deafness?

The occurrence of deafness can be attributed to a number of reasons. The following is a list of the most common causes of deafness.

• In some cases, hearing loss or deafness is due to hereditary factors. Genetics is considered to play a major role in the occurrence of sensorineural hearing loss. Congenital deafness can happen due to heredity or birth defects.
• Human deafness causes also include continuous exposure to loud noises. This is commonly observed in people working in construction sites, airports, nightclubs, etc. This is also experienced by people working with firearms and heavy equipment, and those who use music headphones frequently. The longer the exposure, the greater is the chance of getting affected by hearing loss and deafness.
• Some diseases and disorders can also be a contributory factor for deafness in humans. This includes, measles, meningitis, some autoimmune diseases like Wegener's granulomatosis, mumps, presbycusis, AIDS, chlamydia, etc. Fetal alcoholic syndrome, developed in babies born to alcoholic mothers, can cause hearing loss in infants. Growing adenoids can also cause hearing loss by obstructing the Eustachian tube. Otosclerosis, which is a disorder of the middle ear bone, is another cause of hearing loss and deafness. Likewise, there are many other medical conditions which can cause deafness in humans.
• Some medications are also considered to be the cause of permanent hearing loss in humans, while others can lead to deafness which can be reversed. The former category includes medicines like gentamicin and the latter includes NSAIDS, diuretics, aspirin and macrolide antibiotics. Narcotic pain killer addiction and heavy hydrocodone abuse can also cause deafness.
• Human deafness causes include exposure to some industrial chemicals as well. These ototoxic chemicals can contribute to hearing loss if combined with continuous exposure to loud noise. These chemicals can damage the cochlea and some parts of the auditory system.
• Sometimes, loud explosions can cause deafness in humans. Head injury is another of the causes of deafness in humans.

The above are some of the common causes of human deafness. There can be many other reasons which can lead to deafness or hearing loss in humans. It is always advisable to protect the ears from trauma and other injuries, and to wear protective gear in workplaces, where there are continuous heavy noises.