Types of Hearing Loss
There are three types of hearing loss: conductive, sensorineural, and mixed. Understanding each type gives you a better idea of what hearing loss is, how it works, and why hearing aids are necessary.
Conductive Hearing Loss
Conductive hearing loss occurs when sound cannot pass through the middle ear. In this case, the inner ear and auditory nerve remain unaffected. Individuals with a conductive hearing loss may complain of sounds being muffled or have a fullness or clogged sensation in the ear.
Conductive hearing loss may be temporary or permanent, depending on the source of the problem. Medical management can correct some cases of conductive hearing loss, while hearing instruments may be a recommended treatment option in long-standing or permanent cases.
Possible Causes
- Outer or middle ear infections
- Complete earwax blockage
- Deterioration of the middle ear bones (ossicles)
- Otosclerosis, the fixation of the ossicles
- Perforated tympanic membrane or a hole in the eardrum
- Absence of the outer ear or middle ear structures
Sensorineural Hearing Loss
Sensorineural hearing loss occurs when there is a problem with the sensory receptors of the hearing system, specifically in the cochlea of the inner ear or auditory nerve. People with this type of hearing loss may hear muffled speech, suffer from tinnitus (or ringing in the ears), and have difficulty hearing in background noise or clarity of speech problems.
Sensorineural hearing losses are generally permanent and may remain stable or worsen over time. Routine hearing tests and hearing aids are necessary, allowing hearing professionals to adjust settings as needs change.
Possible Causes
- Congenital, with the hair cells being abnormal since birth
- Damage to hair cells as a result of genetics, infection, drugs, trauma, or over-exposure to noise (late-onset or acquired).
- Presbycusis or age-related hearing loss that commonly causes irreversible hearing deficit
Mixed Hearing Loss
Mixed hearing loss occurs when a person has sensorineural hearing loss in combination with conductive hearing loss. This means there is a problem in the inner ear as well as in the outer and/or middle ear. Mixed hearing loss can sometimes be treated with medical management and hearing aids are a common treatment recommendation.
