Basically there are two types of hearing loss. One is called conductive hearing loss and the other is neurosensory hearing loss (also called Sensory Neural).
CONDUCTIVE HEARING LOSSES
Conductive hearing losses are caused by those problems which interfere with the conduction of sound from the outer part of the ear into the inner part of the ear…the nerve endings. Conductive hearing losses are very important to the Ear, Nose and Throat doctor. These are the types of hearing losses that can be corrected. A few examples of conductive hearing losses include a foreign body in the external canal, fluid in the ears and the fixation of the little bones in the ear (Otosclerosis). The most common types of conductive hearing losses that we see are due to fluid in the ears of children. You can learn more about this from the chapter in the book called “Fluid in the Ears”. Generally speaking, conductive hearing losses are not permanent types of hearing losses. These are ones that usually can be corrected with medications or with surgery.
NEUROSENSORY HEARING LOSSES
Neurosensory hearing losses are caused by damage to the nerves involved with hearing. Some examples would be hearing loss caused by old age, noise exposure, severe infection of the ear, acoustic trauma (such as an explosion going off nearby) or damage caused by medications. All of these cause damage to the nerve endings or the nerve in the ear. These types of problems generally are not correctable by surgery or medication. The hearing loss seen with increasing age is progressive with very little hope of regeneration of the nerves or better hearing. In the past several years there have been advances made surgically to help people with profound neurosensory hearing loss or nerve damage. The Cochlear implant is an electronic device that is placed under skin and has a wire leading into the inner ear and nerve endings. Coupled with a transmitter, the patient is able to receive some sound through that ear. The cochlear implant is limited in the types of people who qualify for that particular type of surgery. At this time only the totally deaf are considered for this surgery. About the best treatment that is available for people with neurosensory hearing loss is a hearing aid. With very severe hearing loss, unfortunately even a hearing aid does not improve what the patient can hear.
MIXED HEARING LOSS
Mixed hearing loss is a combination of both conductive loss and neurosensory hearing loss.