Types of Hearing Loss

Hearing loss can be categorized by which part of the auditory system is damaged.  The three basic types of hearing loss: conductive hearing loss, sensorineural hearing loss, and mixed hearing loss.

Conductive Hearing Loss

Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones, or ossicles, of the middle ear.  Conductive hearing loss usually involves a reduction of sound and causes the inability to hear soft sounds.  Often this type of hearing loss can be corrected medically or surgically. Examples of conditions which may cause a conductive hearing loss include:
  • Earwax blockage
  • Perforation of the eardrum
  • Infection in the ear canal
  • Middle ear fluid

Sensorineural Hearing Loss

Sensorineural hearing loss occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear (retrocochlear) to the brain.  This type of hearing loss cannot be medically or surgically corrected.  It is a permanent hearing loss.  Often this type of hearing loss not only involves a reduction of sound and the inability to hear soft sounds, but also affects speech understanding, or ability to hear clearly.  Examples of conditions causing sensorineural hearing loss include:
  • Normal aging process (presbycusis)
  • Noise exposure
  • Viruses
  • Head trauma
  • Tumors
  • Genetic conditions

Mixed Hearing Loss

In some cases a conductive hearing loss occurs in combination with a sensorineural hearing loss.  In these cases there may be damage in the outer or middle ear and the inner ear (cochlea) or auditory nerve.  When this occurs, the hearing loss is referred to as a mixed hearing loss.