Types of Hearing Loss

Conductive Hearing Loss 

A conductive hearing loss is caused by any condition that interferes with the transmission of sound through the outer and/or middle ear to the inner ear. This may be due to interference in the external ear canal, mobility of the eardrum, the three small bones in the middle ear, the middle ear cavity, the openings to the inner ear, and/or the Eustachian tube (the tube which connects the middle ear to the back of the throat). Anything that completely blocks the ear canal can cause this type of hearing loss. One common factor is blockage of earwax. Some other causes of blockage include infections with swelling, foreign bodies in the ear, injury, birth defects, and a growth in the ear canal. Problems that can affect the middle ear include ear infections, fluid in the ear, otosclerosis, birth defects and tumors. Blockage decreases the volume but generally does not produce much distortion. Conductive hearing losses are successfully treated in most cases either medically, surgically or with the use of a hearing aid to provide amplification.  

Sensoineural Hearing Loss 

A sensorineural hearing loss is caused by damage in the inner ear, the acoustic nerve, or both. The hair cells and nerve which connects them to the brain are susceptible to damage from a variety of causes. Several conditions may cause the inner portion of the ear to function abnormally. These include but are not limited to: otosclerosis, prebycusis, fistula, head injury, Meniere’s syndrome, noise, infections, sudden deafness, and neural problems. This type of hearing loss is harder to treat however with continuing medical advances treatment cannot be ruled out. 

Central Hearing Loss 

Central hearing loss is caused by problems arising in the central nervous system, at some point within the brain. Some individuals may have perfectly normal hearing but have difficulty understanding and/or interpreting what is said. One factor in this type of loss is a person’s inability to filter out competing auditory signals. Individuals with this type of loss have difficulties which can include: problems “hearing” when there are several conversations going on, an inability to read or study with the radio or television on, problems reading if someone turns on a vacuum cleaner or air conditioner near them, generally missing the first sentence from people talking to them if they are involved in an auditory attention task (i.e., watching television).  

Mixed Hearing Loss 

This occurs when both a conductive and sensorineural hearing loss are present in the same ear.