The deafness type depends essentially of the location of the pathology at the level of the ear.

One classical distinguishes 3 types of deafness: - The deafnesses of pure transmission - The deafnesses of pure perception
- The mixed deafnesses

A- The deafnesses of pure transmissions:

They are related to an attained one external ear or average ear. They result from a defect of transmission of sonorous vibrations towards the ear internal by the system tympano-ossiculaire. The treatment can be medical but it is most often surgical, with of excellent results.

B- The deafnesses of pure perceptions:

They are related to an attained one internal ear They result from a defect of transduction mécano-électrique by the organ neuro-sensoriel. The treatment is essentially medical, with variable results according to etiology. They can be improved by an auditory casting off.

C- The mixed deafnesses

They combine the two attained ones: transmission and perception, to variable degrees. They reply to the same treatments corresponding, medical or surgical, according to etiology. They can equally benefit from the harbor of an auditory prosthesis.