Sensory hearing loss, also known as sensorineural hearing loss, is the result of a damage of the cochlea or of the auditory nerve. Such damages may be hereditary or they may occur as a consequence of diseases such as meningitis, mumps, syphilis, toxoplasmosis, Waardenburg’s syndrome, Alport’s syndrome or Meniere’s disease. It has been estimated that about 30% of people who suffered from meningitis develop sensory hearing loss. Aging can be another cause for this type of hearing deficiency, because of degenerative processes that take place as the human body gets older, and which can impact the hair cells of the organ of Corti, situated in the cochlea. In most of the cases, sensory hearing loss is a permanent ailment, very hard if not impossible to be treated medically or surgically.

Cochlear damage which can go as bad as to lead to complete deafness may also be induced by long-term, repeated exposure to loud noise, like in the case of musicians, who are exposed to high-frequency sounds, or in the case of workers who work in a noisy environment. This is why musicians should wear special earplugs or mute their instruments when practicing, in order to minimize the damage. In the US, noisy occupations are regulated by laws which enforce noise protection means as compulsory for such workplaces. Even the common mp3 player headphones we all are so familiar with may cause hearing loss if one listens to very loud music for as long as a few hours. Studies have shown that even intensities of 70 dB, which are not the maximum possible for such devices, can result in hearing loss.

Sensory hearing loss is diagnosed with the help of an audiogram, which can also provide information regarding on the prognosis of the disease. It is treated with hearing aids or cochlear implants.