Hearing loss is grouped in a variety of different ways. The specific section of the auditory system affected determines the categorization. In this short article we provide an introduction to five categories – sensorineural, conductive, functional, central and mixed. The starting point in creating a therapy plan is to accurately diagnose the type of hearing impairment.
Conductive hearing loss – In situations where sound waves aren’t adequately conducted to the inner ear through the parts of the outer and middle ear, conductive hearing loss occurs. Conductive hearing loss is very common and can be caused by a buildup of ear wax, a buildup of fluid in the eustacian tube, which prevents the eardrum from moving properly, a middle ear infection, a perforated eardrum, disease of the tiny bones of the middle ear and other obstructions in the ear canal.
Most instances of this type of hearing loss are reversible, presuming there is no permanent damage to the regions of the middle ear, and with proper treatment the problem usually resolves fairly quickly. In some cases surgery can help to correct the condition or a hearing aid may be recommended.
Sensorineural hearing loss – This type of hearing loss accounts for over 90% of the instances in which a hearing aid is worn. Sensorineural hearing loss is the result of damage in the inner ear or damage to the acoustic nerve, which blocks sound signals from reaching the brain. Also referred to as nerve deafness or retrocochlear hearing loss, the impairment is more often than not permanent, though breakthroughs in technology have enabled some formerly untreatable cases to see some improvement.
The most frequent factors that cause sensorineural hearing loss are aging, extended exposure to noise, complications with blood circulation to the interior of the ear, fluid disturbance in the inner ear, medicines that cause injury to the ear, some diseases, genetics and problems with the auditory nerve.
Hearing aids are sufficient for the majority of people that have this kind of hearing loss, but in more serious cases, a cochlear implant can help restore hearing to those individuals for whom a conventional hearing aid is not enough.
Central hearing loss – This condition occurs when a problem in the CNS (central nervous system) prevents sound signals from being processed and interpreted by the brain. Affected individuals can ostensibly hear just fine, but cannot understand or interpret what is being said. Many cases involve a problem with the individual’s ability to properly filter competing sounds. For example, the majority of us can hold a conversation with traffic noise in the background, but individuals with this problem have a really hard time with this.
Functional hearing loss – A rare occurrence, this type of hearing loss is not physical. Functional hearing loss is due to psychological or emotional problem in which the person’s physical hearing is normal, however they do not seem to be able to hear.Mixed hearing loss – As suggested by the term, mixed hearing loss is a combination of multiple types of hearing loss, in this case the combination of conductive and sensorineural hearing loss. Though there are a couple of other types of hearing loss, the combination of these two is most frequent.