There are several reasons behind the loss of hearing in adults, in which the most common causes are exposure to noise, cancer, distress, infection, drugs(especially ototoxic) and most especially, aging. Below are a few reasons why adults lose their hearing abilities:
In adults, Presbycusis is the most common cause of hearing loss. It is associated with the gradual and progressive changes that occur in the auditory system. Mostly, it is a result of the aging process as the high frequencies are first affected.
Noise-Induced Hearing Loss accounts for the second most common reasons behind acquired sensorineural hearing loss in adults. This type of hearing loss involves painless and progressive stages. When a person is exposed to loud noises for a long time, the hair cells in the cochlea are damaged, causing the person to lose his hearing ability permanently. While acoustic trauma may be the cause of the person’s hearing impairment, the person’s hearing loss may also result from exposure(s) to deafening noises. Consequently, the Organ of Corti in the inner ear breaks down completely. Furthermore, when as a result of prolonged exposure to high-frequency sounds (such as music, noises from machines or a short, loud and sudden sound such as a gunshot), the hair cells collapse and lose their ability to be stimulated by incoming sounds. The moment the hair cells lose their collapse and lose their function, it will become impossible to fix them.
Otitis media is an ear infection that allows fluid to pile up behind the eardrum in the internal space of the ear. Naturally, space is usually occupied by air but as a result of the incapability of the Eustachian tube to equalize the atmospheric pressure in the internal ear, the fluid increases. Allergies or infection in the upper respiratory tract may cause Eustachian tube dysfunction.
Otosclerosis is an ear disease that advances gradually. It is associated with the obstructed movement of the stapes (one of the three small bones) inside the middle ear bony capsule.
Meniere’s disease is another progressive ear disease. It involves the varying sensorineural hearing impairment, tinnitus (vibration inside the ear) and vertigo (dizziness).
Ototoxic drugs are drugs that, are although used to treat other diseases, damage the auditory system thereby resulting in hearing impairment permanently. Commonly, the most recognized ototoxic drugs are antibiotics (examples are Streptomycin, Kanamycin, and Neomycin) and generally, drugs containing aspirin and quinine to certain levels. Also, in chemotherapy, some medications used in the treatment routine are found to be ototoxic. However, the extent of harm these drugs does depend on how long the duration of the drug usage was and how much the dosage was.
Acoustic Neuroma is a type of tumor that results in sensorineural hearing impairment. The condition originates in the 8th cranial (acoustic) nerve, causing the sufferer to undergo an autonomous hearing impairment, ringing in one ear or vertigo.
As a physical factor, trauma can cause sensorineural, conductive or diverse hearing impairments. When shock (trauma) is felt by the ear or the side of the head, damage can occur to the ear as a result of the delicate nature of the ear and its components. Related causes are the effects of foreign objects on the eardrum, fractures of the temporal bone and abrupt variation in atmospheric pressure.
Sudden hearing loss is a situation whereby a person suddenly loses his hearing ability. This condition might be due to environmental factors, infection or effects of drugs in the body system. Nonetheless, sometimes, there is no reasonable cause of the hearing impairment. However, two assumptions generally define the reasons behind such hearing losses; Vascular Occlusion and Viral Labyrinthitis. Vascular Occlusion is a situation whereby the blood supply to the cochlea is suddenly stopped, while Viral Labyrinthitis a viral infection of the inner ear that damages the components in the inner ear.