The ear is an essential yet delicate organ. It helps us not only hear but interpret sounds in our environment. Hearing involves changing sound waves in the air into electrical signals that are then transmitted to the brain. Hearing loss happens when one or more parts of the ear, hearing part of the brain or nerves coming from the ear are not working as they should.
Common types of hearing loss
Sensorineural hearing loss is the damage of either the auditory nerve or the stereocilia (tiny hair-like cells). The sound still reaches the inner ear, but the damaged hair cells or auditory nerve cannot convert and pass it on to the brain clearly. Most people with sensorineural tend to hear though not clearly.
Conductive hearing loss occurs when there is an obstruction to the outer, ear canal or middle ear. The sounds levels tend to reduce as they reach the cochlea making soft sounds a struggle to hear.
Sensorineural versus conductive hearing loss
One of the ways to tell whether you have either of the two is by knowing what triggers each.
Sensorineural is a permanent hearing loss that has several causes:
- Presbycusis (ageing)
- Genetic syndrome
- Exposure to loud noises
- Birth defects
- Different types of illnesses such as diabetes
- Ototoxic drugs
- Infections
- Neurological conditions like stroke
Conductive hearing loss may be permanent or temporary subject to the cause. Causes of obstructions in the outer ear are wax impaction, microtia, exostoses (bone-like protrusions), foreign bodies and stenosis.
Other causes that may prevent sound from being conducted to the inner ear include:
- Breach in the eardrum caused by an injury
- Otitis media (many episodes of ear infection)
- Ossicular chain discontinuity (a broken connection between bones)
- Otosclerosis (abnormal bone growth near the middle ear)
- Tumours and Tympanoclerosis (thickening of the eardrum)
Symptoms of conductive and sensorineural hearing loss
Sensorineural hearing loss is about the loudness and clarity of a sound. One can know if they have sensorineural if they hear but cannot understand, they have difficulties hearing high-pitched sounds or listening in noisy places. Other symptoms are difficulty following conversations when one or two people speak, straining with certain speech sounds and ringing or buzzing in the ear.
Conductive hearing loss is more about the loudness of the sound and not clarity. In most cases, turning up volumes improves the hearing. Pain in one or both ears, a sensation of pressure in one or both ears and foul odour from the ear canal are the common symptoms. Other symptoms include feeling that one’s voice is louder or different and having difficulties with phone conversations.
Treatment options for sensorineural and conductive hearing loss
Though the damaged hair cells do not regenerate, patients with sensorineural hearing loss patients can benefit from cochlear implants, assistive listening devices and power-hearing aids.
Conductive hearing loss is treatable with medical or surgical treatment. However, hearing loss caused by Ossicular chain separation or stenosis of the ear canal are permanent conditions. Such instances require hearing aids or bone-anchored hearing aids (Baha) devices.
Knowing the symptoms and the causes of conductive and sensorineural hearing loss makes you aware of your condition. However, to understand the state of your hearing, it is vital to undertake hearing tests like air conduction tests or bone conduction testing.
