Homeostatic Imbalances of Hearing

Deafness

Any type of hearing loss, no matter how small, is considered deafness of some degree. This may include lack of ability to hear certain frequencies, to lack of ability to hear at all. There are two types of deafness, which are described below.

A) Conduction Deafness
          Conduction deafness is when sound vibrations are not properly delivered to the fluid of the inner ear. There are many causes of this problem, such as earwax or a ruptured eardrum. However, the most common cause, which is also an age-related problem, is otosclerosis of the ossicles. This problem occurs when overgrowth of bone fuses the ossicles together or fuses them to the oval window. Therefore, sound is not properly conducted to the perilymph inside the cochlea. This problem can be treated with surgery.

B) Sensorineural Deafness
          Sensorineural deafness is a result of nerve damage inside the inner ear. When this occurs, the hair cells in the cochlea can't send signals to the brain properly resulting in an inability to recognize sound. This condition worsens with age as the nerves inside the ear get degraded with time. Prolonged exposure to high intensity sounds damages the cilia of the hair cells and can lead to this problem as well. Implanted devices or hearing aids can sometime make this problem less severe.