Hearing loss occurs when there is a problem with one or more parts of the ear.

In air conduction, sound waves travel through the external ear canal to vibrate the eardrum. Vibration of the eardrum is transmitted to the hearing organ (cochlea) via three small bones (ossicles) in the middle ear. This stimulates the sensory cells in the cochlea which then sends impulses to the hearing nerve (auditory nerve) and on to the brain.

Hearing by bone conduction occurs when sound waves cause the bones of the skull to vibrate which directly stimulate the hearing organ (cochlea) resulting in hearing.