There are two primary types of hearing loss: sensorineural loss and conductive loss.

Ninety-five percent of all hearing aid wearers have sensorineural hearing loss, which usually occurs when the tiny hair cells that line the inner ear become damaged and can no longer transmit signals accurately to the auditory pathway and the brain. Aging is by far the most common cause of this damage, but other causes include infection, high fever, trauma, noise exposure, genetics, and use of certain prescription drugs.

In rare cases, hearing loss results from damage to the auditory nerve. For example, benign tumors can compress the nerve. If detected early, these conditions are often treatable.

Conductive hearing loss occurs when something interferes with sound vibrations as they pass through the outer and middle ear. A common cause is a blockage of wax buildup, which can be addressed by using an earwax softener and then flushing out the wax using a kit (both available at drug stores). A physician or audiologist can also remove the wax.

Conductive hearing loss can also result from the presence of fluid in the middle ear. The fluid disrupts the middle ear’s ability to conduct vibrations to the inner ear. This can occur when the Eustachian tube (a tiny tube connecting the middle ear to the back of the throat) is not functioning properly, often due to inflammation. This sort of hearing loss, common in children, usually can be treated medically.

A punctured eardrum or problems with the functioning of the small bones in the middle ear can also cause conductive hearing loss. While these types of problems are often partially or completely treatable with surgery, hearing aids may be used if hearing loss remains following the completion of medical intervention.

A combination of conductive and sensorineural hearing loss, called mixed loss, is also possible.