In the same way that there are numerous reasons for hearing loss, there are many different forms of hearing loss; understanding the manner in which we hear is the first step in understanding the distinct types. We collect sounds through the outer ear, which is not just the portion of the ear on the outside of our heads, but also the eardrum and the ear canal. The eardrum can also be viewed as part of the middle ear, an area that also includes the 3 small bones called ossicles that carry the vibrations of sound and send them to the inner ear. The inner ear has three major parts – the cochlea, the two semi-circular canals (essential for balance) and the acoustic nerves which transmit the impulses to the brain. All areas of the ear are sophisticated and fragile. Problems in any of the 3 sections – outer, middle or inner ear – can cause hearing impairment. There are 4 main classifications of hearing loss.
The first classification is conductive hearing loss, which is caused by an obstruction or interference that hinders the sounds from being transmitted through the outer or middle ear. Hearing aids can manage conductive hearing loss if medication or surgery cannot treat it.
The second classification is sensorineural hearing loss, which is caused by damage in the inner ear – to the cochlea, to the hair cells lining the inner ear, or to the acoustic nerves themselves. Hearing aids are usually the best option for treating sensorineural hearing loss, as most cases are not successfully remedied with medication or surgery.
Mixed hearing loss involves both sensorineural and conductive hearing loss, and can occasionally (but not always) be treated with a combination of surgery, medication, and/or hearing aids.
Central hearing loss occurs when sound enters the ear normally, but because of damage either to the inner ear (especially to the cochlea) or to the auditory nerves, it cannot be organized in a way that the brain can understand.
All hearing loss classifications include sub-categories for the degree of hearing loss and are classified as mid-level, moderate, severe, or profound. Hearing loss can also be classified as either unilateral or bilateral (occurring in only one ear or both ears), as pre-lingual or post-lingual (occurring either before or after learning to speak), and symmetrical or asymmetrical (occurring to the same or different degree in both ears). Additional sub-categories of hearing loss includes whether it is progressive vs. sudden, whether the hearing loss is fluctuating vs. stable, and whether the hearing loss was present at birth (congenital) or developed later in life (acquired). The most important thing to bear in mind, however, is that whatever type of hearing loss you may have incurred, our specialists can help you to diagnose and treat it properly.