Beginner’s Guide to Hearing Impairment Classification Terminology


Understanding the way we hear is the first step in understanding the many reasons for hearing loss and the different types of hearing loss. Including the ear canal and the eardrum, the outer ear is the part of the ear on the exterior of the head which receives sounds. In the middle ear three miniature bones called ossicles transmit sounds to the inner ear by converting sounds into vibrations.The inner ear is made up of a snail-shaped organ known as the cochlea, two semicircular canals which help us keep our balance, and the acoustic nerves which lead to the brain. All sections of the ear are complex and fragile. Problems in any of the three sections – outer, middle or inner ear – could cause hearing problems. Hearing loss is usually split into 4 main classifications.

The first class is conductive hearing loss, which is due to a blockage or interference which hinders the sounds from being transmitted through the outer or middle ear. Hearing aids can treat conductive hearing loss if medication or a surgical procedure cannot remove the blockage.

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.

The third classification is mixed hearing loss, which is a combination of conductive and sensorineural hearing loss, and which can often be treated using the same combinations of surgery, medication, and 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.

Each of these four main classifications contain several sub-categories, such as the degree of hearing loss, which can be mid-level, moderate, severe, or profound. Additional sub-categories include whether the hearing loss occurs in one ear or both ears (unilateral vs. bilateral), whether it occurs at the same degree in both ears (symmetrical vs. asymmetrical), and whether the hearing loss happened before or after the person learned to speak (pre-lingual vs post-lingual). 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). Whatever the cause of your hearing loss, our specialists will help you diagnose the cause and help you treat it properly and effectively.

The site information is for educational and informational purposes only and does not constitute medical advice. To receive personalized advice or treatment, schedule an appointment.