Hearing problems are grouped in a number of different ways. The exact part of the auditory pathway affected is what determines the categorization. The hearing loss may be conductive, sensorineural, mixed, central or functional.
The initial step in developing a therapy plan is to accurately identify the kind of hearing loss.
Sensorineural hearing loss – This type of hearing loss is responsible for over 90% of the cases in which a hearing aid is worn. It is due to damage in the inner ear or to the acoustic nerve, which blocks sound signals from reaching the brain. Also referred to as nerve deafness or retrocochlear hearing loss, the damage is generally speaking irreversible, although improvements in technology have enabled some formerly untreatable cases to see some improvement.
The most common reasons behind sensorineural hearing loss are the aging process, extended exposure to noise, complications with blood circulation to the interior of the ear, fluid disturbance in the inner ear, drugs that cause injury to the ear, a small number of diseases, heredity and problems with the auditory nerve.
Hearing aids are satisfactory for the majority of people who have this sort of hearing loss, but in more severe cases, a cochlear implant can help bring back hearing to those for whom a standard hearing aid is not enough.
Conductive hearing loss – In situations where sound waves are not sufficiently conducted to the inner ear through the outer and middle ear, conductive hearing loss occurs. Conductive hearing loss is quite common and could be caused by a buildup of ear wax, an accumulation of moisture in the eustachian tube, which keeps the eardrum from moving, a middle ear infection, a perforated eardrum, disease of the tiny bones of the middle ear or obstructions in the ear canal.
The majority of instances of conductive hearing loss are reversible, assuming there isn’t any irreversible damage to the parts of the middle ear, and with treatment the problem usually clears up in a short amount of time. In some cases a surgical procedure can help to correct the condition or a hearing aid may be fitted.
Central hearing loss – Central hearing loss arises when a problem in the central nervous system blocks sound signals from being processed by the brain. The person affected can seemingly hear perfectly well, but cannot decode or interpret what is being said. Numerous cases involve a problem with the person’s capacity to adequately filter competing sounds. For instance, the majority of us can hold a conversation while there is traffic noise in the background, but individuals with central hearing loss have a really hard time with this.
Mixed hearing loss – As suggested by the term, mixed hearing loss is a mixture of multiple types of hearing loss, in this case the combination of sensorineural and conductive hearing loss. Though there are a couple of other types of hearing loss, the combination of these 2 is most frequent.
Functional hearing loss – A rare occurrence, this type of hearing loss does not have a physiological explanation. This condition is due to psychological or emotional problems in which the person’s physical hearing is found to be normal, however they are not able to hear.