Hearing loss can happen when any part of the ear or auditory (hearing) system is not working in the usual way.
There are four types of hearing loss:
- Sensorineural: hearing loss that occurs when there is a problem in the inner ear or how the hearing nerve works.
- Conductive: hearing loss caused by something that stops sounds from getting through the outer or middle ear. This type of hearing loss can often be treated with medicine or surgery.
- Mixed: hearing loss that includes both a conductive and a sensorineural hearing loss.
- Auditory Neuropathy Spectrum Disorder: is a hearing disorder in which the inner ear successfully detects sound, but has a problem with sending sound from the ear to the brain.
The degree of hearing loss can range from mild to profound:
- Mild Hearing Loss: A person with a mild hearing loss may hear some speech sounds but soft sounds are hard to hear.
- Moderate Hearing Loss: A person with a moderate hearing loss may hear almost no speech when another person is talking at a normal level.
- Severe Hearing Loss: A person with severe hearing loss will hear no speech when a person is talking at a normal level and only some loud sounds.
- Profound Hearing Loss: A person with a profound hearing loss will not hear any speech and only very loud sounds.
Hearing loss can also be described as:
- Unilateral or Bilateral: Hearing loss is in one ear (unilateral) or both ears (bilateral).
- Pre-lingual or Post-lingual: Hearing loss happened before a person learned to talk (pre-lingual) or after a person learned to talk (post-lingual)
- Symmetrical or Asymmetrical: Hearing loss is the same in both ears (symmetrical) or is different in each ear (asymmetrical).
- Progressive or Sudden: Hearing loss worsens over time (progressive) or happens quickly (sudden).
- Fluctuating or Stable: Hearing loss gets either better or worse over time (fluctuating) or stays the same over time (stable).
- Congenital or Acquired/Delayed Onset: Hearing loss is present at birth (congenital) or appears sometime later in life (acquired or delayed onset).
Possible Causes of hearing loss:
- noise exposure
- Ototoxic medication
- Illness or infections
- Autoimmune disease
- Chronic diseases
Content source: Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilties