Hearing Loss

Hearing loss and deafness are conditions that affect millions of people around the world and can be caused by various factors, including genetics, noise exposure, infections, and aging. There are several types of hearing loss, ranging from mild hearing loss to complete deafness.

deafness

Deafness is the partial or complete inability to hear. Some people are born without hearing, which is known as congenital deafness.

Given the mechanical nature by which the sound wave stimulus is transmitted from the eardrum through the ossicles to the oval window of the cochlea, some degree of hearing loss is inevitable. For example, some people have conductive hearing loss.

conductive hearing loss

In conductive hearing loss, hearing problems are associated with a failure in the vibration of the eardrum and/or movement of the ossicles. This causes issues with delivering sound energy to the cochlea.

Causes for conductive hearing loss primarily relate to issues in the outer or middle ear, including blockage of the ear canal, a hole in the tympanic membrane, problems with the ossicles, or fluid in the space between the eardrum and cochlea.

 

This can be treated by surgery, medication, or through devices like hearing aids that amplify incoming sound waves to make the vibration of the eardrum and movement of the ossicles more likely to occur.

Another group of people have sensorineural hearing loss, which is the most common form of hearing loss.

sensorineural hearing loss

When the hearing problem is associated with a failure to transmit neural signals from the cochlea to the brain, it is called sensorineural hearing loss, affecting the inner ear or cochlea. This type of loss accelerates with age and can be caused by prolonged exposure to loud noises (noise-induced hearing loss, as shown in Figure 1), which causes damage to the hair cells within the cochlea.

Although sensorineural hearing loss is associated with aging and noise exposure, it can be caused by many other factors, such as head or acoustic trauma, infections and diseases (such as measles or mumps), medications, and environmental effects such as tumors, and toxins (such as those found in certain solvents and metals).

Sensorineural hearing loss is not reversible but can be managed with hearing aids or cochlear implants. For patients with mild-to-moderate sensorineural hearing loss, conventional hearing aids are helpful, though once the damage to the hair cells is profound, then amplifying the sound through a hearing aid is insufficient, and cochlear implants would be needed for hearing.

Cochlear implants are electronic devices that consist of a microphone, a speech processor, and an electrode array. The device receives incoming sound information and directly stimulates the auditory nerve to transmit information to the brain.

One disease that results in sensorineural hearing loss is Ménière’s disease. Although not well understood, Ménière’s disease results in a degeneration of inner ear structures that can lead to hearing loss, tinnitus (constant ringing or buzzing), vertigo (a sense of spinning), and an increase in pressure within the inner ear (Semaan & Megerian, 2011).

Deaf Culture

In the United States and other places around the world, deaf people have their own languages, schools, and customs. This is called deaf culture. In the United States, deaf individuals often communicate using American Sign Language (ASL); ASL has no verbal component and is based entirely on visual signs and gestures. The primary mode of communication is signing. According to the World Federation of the Deaf, there are over 300 different sign languages used worldwide. One of the values of deaf culture is to continue traditions like using sign language rather than teaching deaf children to try to speak, read lips, or have cochlear implant surgery.

When a child is diagnosed as deaf, parents have difficult decisions to make. Should the child be enrolled in mainstream schools and taught to verbalize and read lips? Or should the child be sent to a school for deaf children to learn ASL and have significant exposure to deaf culture? Do you think there might be differences in the way that parents approach these decisions depending on whether or not they are also deaf?