Hearing Loss

Overview

Hearing loss falls into two general categories: sensorineural and conductive.

Sensorineural Hearing Loss

Sensorineural hearing loss happens when the inner ear loses its ability to transform sound waves into nerve impulses due to the normal aging process, or to continued exposure to loud noises.

The cochlea is a structure in the inner ear shaped like a snail shell. It contains a special fluid and is lined with a large number of hair cells, which act as sensory receptors. Transmitted sound vibrates the cochleal fluid. The hair cells detect the movement and transform it into nerve impulses, which are passed on to the brain. When your hair cells are damaged, your inner ear loses the ability to transform sound waves and you experience hearing loss.

Sensorineural hearing loss cannot generally be reversed, but treatment may restore some of your hearing ability.

Conductive Hearing Loss

Hearing is the process of conducting sound waves from the air outside the ear to the sensory structures of the inner ear. Your inner ear transforms sound into nerve impulses, then transmits the nerve impulses to the brain. Conductive hearing loss occurs when a blockage or damage interferes with this process, preventing parts of your middle ear from conducting sound to the inner ear.

Common reasons for conductive hearing loss include:

• Blockages, such as earwax and fluid buildup in the middle ear (immediately behind the eardrum).
• Burst or damaged eardrum, caused by injury or sudden changes in air pressure.
• Cholesteatoma, a tissue growth, has developed in the bones of the middle ear, hindering sound transmission.
• Otosclerosis, a bony overgrowth that limits the movement of tiny bones in your middle ear, thereby reducing transmission of sound to your inner ear.

Conductive hearing loss can often be reversed with treatment.

Treatment

If you suffer from hearing loss, IU Health otolaryngologists can diagnose the cause and provide a number of treatments to help improve or reverse it.

Cochlear Implants

If you have severe sensorineural hearing loss, cochlear implants may help restore some of your hearing. The implant work using a pair of devices, one outside the body, and the other implanted in the head near the ear. The external device receives sound and translates it into electrical impulses. These impulses are transmitted to the internal device, which then sends them directly to your auditory nerve.

Hearing Aids

Hearing aids can overcome some sensorineural hearing loss by amplifying sound directly into your ear canal.

Removal of Blockage

Earwax and other objects blocking your ear canal are removed to partially or completely restore conductive hearing loss. Removal of the blockage allows sound to reach your eardrum unimpeded.

Surgical Repair

When a burst eardrum does not heal by itself, surgical repair may restore healing. Surgical rebuilding and correction are available for the treatment of otosclerosis or cholesteatoma.

Ventilation Tubes

When chronic infections cause pressure in the middle or inner ear, medical treatment doesn’t always help. Ventilation tubes can be inserted into the eustachian tubes (passages that lead from the ear to the back of the throat) to relieve pressure inside your ear.

Research

Cochlear implants may not be as effective for children who have not developed language ability or for adults who were born deaf or who became deaf before acquiring language. This often means they cannot develop an understanding of spoken language or translate speech into meaning. The implant still functions, but the brain is unable to recognize how the electrical impulses translate into language.

Adults with implants may recover the ability to have conversations, even on the phone. Children with these devices may achieve oral communication as their primary mode of communication, but there is some variability in outcomes and levels of language development. IU Health actively conducts research to expand knowledge and understanding on the processes at play between hearing loss and cochlear implants, and continues to seek solutions that lead to better outcomes.