There are three major types of hearing loss:

• Conductive hearing loss. Occurs when a blockage (e.g., ear infection) or structural problem interferes with the process of sound transmission in the outer or middle ear. In most cases, this type of hearing loss is mild and disappears when the underlying condition is treated with medication or surgery. In some cases, a congenital structural abnormality causes conductive hearing loss, which is usually permanent. Conductive hearing loss is the most common type of hearing impairment in children.
  
  
• Sensorineural hearing loss. Occurs when the signal gets through the outer and middle ear, but is not properly converted and interpreted by the brain due to malformation, dysfunction or damage to structures in the inner ear such as the cochlea or hearing nerves. Typically, the tiny hairs in the cochlea that transmit sounds to the brain are damaged or destroyed, causing hearing loss. This type is usually present at birth and may be the result of genetics or a medical problem. The degree of hearing loss can range from mild to profound. It may be evident in just one ear or in both ears, and may get progressively worse over time. In most cases, children with sensorineural hearing loss will not regain a normal level of hearing. However, hearing aids can help children with this type of loss to hear sounds more clearly.
  
  
• Mixed hearing loss. Occurs when hearing loss is a result of both conductive and sensorineural factors.