Deafness, hearing impairment, or hearing loss is the inability to perceive sounds. Different patients experience different symptoms ranging from mild to severe. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), at least 25 percent of people suffer from hearing impairments. The majority of these people are between 65 and 74 years.
In some cases, people with hearing impairment rely on lip-reading to communicate effectively with others. On the other hand, severely deaf persons use sign language.
How Does Hearing Occur?
Have you ever been curious about how hearing occurs? Here is a brief explanation of the hearing process. Hearing occurs when sound waves travel from the outer ear to the eardrum, a thin layer of skin between the outer and middle ear. There are structures in the middle ear known as ossicles made up of stirrup, anvil, and hammer. The ossicles and eardrums work in harmony to amplify the sound vibrations transmitted to the inner ear.
On reaching the inner ear, vibrations move through a liquid substance, the cochlea. The cochlea, a snail-shaped feature found in the inner ear, contains nerve cells full of tiny hairs. The hairs convert sound waves into electrical signals transmitted through the brain. The brain interprets the electrical signals into particular sounds.
What Causes Hearing Loss?
The natural aging process and exposure to loud noise are common causes of hearing loss. Some medical conditions can also predispose a person to loss of hearing. They include:
The loudness required so that a patient can detect sound measures the severity of the hearing disorder. According to the American Speech-Language-Hearing Association (ASHA), the most common types of deafness are sensorineural hearing loss (SNHL), conductive hearing loss, and mixed hearing loss.
Sensorineural Hearing Loss (SNHL)
SNHL occurs when the inner ear nerves, cochlea, auditory nerve, and hair cells suffer from exposure to noise or congenital deformity, head trauma, and aging. Damage to these organs directly affects the nerves from the inner to the brain. Unfortunately, some infections like mumps, measles, scarlet fever, and meningitis may cause SNHL.
Doctors consider sudden SNHL an otologic emergency, meaning that successful recovery depends on prompt treatment. In treating this condition, medics use corticosteroids. These drugs help to reduce inflammation after exposure to loud noise.
Hearing aids help manage the most prevalent form of hearing loss due to advancements in age. In cases where hearing aids fail to address the condition, doctors usually recommend cochlear implant surgery. However, if you suffer severe damage to the inner ear, medical interventions cannot prevent hearing loss.
Conductive Hearing Loss
Conductive hearing loss occurs when sound vibrations cannot travel through the outer ear to the middle ear. Persons experiencing this condition are unable to perceive soft and muffled sounds. Common causes of conductive hearing loss include allergies, ear infections, wax build-up in the ear and swimmer's ear (a bacterial infection caused by water in the outer ear canal for a long time; the water provides a moist environment for bacteria to grow). If left untreated, ear infections may result in scar tissue that reduces eardrum function.
Doctors administer antifungal drugs to treat ear infections. Surgery is necessary in the case of tumours. The hearing nerve's condition can determine the best solution to improve hearing. The solutions can be using Osseo integrated devices, bone-conduction hearing aid, or regular hearing aid.
Conductive hearing loss due to the ear canal's failure to open at birth is treatable with surgery. Similarly, surgery helps manage conductive hearing loss due to malformation and other dysfunctions.
Mixed Hearing Loss
Mixed hearing loss refers to both sensorineural and conductive hearing loss. For instance, long-term infections may cause damage to the ossicles and the eardrum.
Audiologists often advise patients to deal with conductive hearing loss before handling the sensorineural component. Doctors categorize hearing loss depending on whether it has occured before or after speech development and if it affects one or both ears, in addition they assess the person to determine the most appropriate hearing aid.
Pre-lingual deafness refers to the inability to perceive sounds or acquire partial hearing before introducing speech. Persons with this condition are usually born with congenital deformities and into families without hearing difficulties. Persons with pre-lingual deafness are encouraged to learn sign language early.
A person has post-lingual deafness if they develop a hearing impairment after learning to speak. Post-lingual deafness commonly occurs due to trauma, ear infections, side effects of medication, or medical conditions. The severity of the hearing loss dictates whether the person will acquire hearing aids, learn sign language or undergo cochlea surgery.
Unilateral and Bilateral Deafness
Unilateral or single-sided deafness refers to hearing impairment in one ear. Bilateral deafness, on the other hand, is a condition where you experience hearing impairment in both ears. Persons with this disability have difficulty holding conversations in noisy environments since it is challenging to identify the sound source.
The Four Levels of Deafness
Describes a person who can only perceive sounds between 25- 29 decibels (dB). Persons with this condition may have trouble understanding what you are saying, and mostly rely on lip-reading.
Persons with this condition can only detect 40-69 decibels (dB) sounds. Since it is hard to grasp everything said during a conversation, they use a hearing aid.
The person can only detect sounds between 70 and 89 (dB). Persons with this condition rely heavily on lip-reading and sign language to communicate effectively.
This degree comprises persons who can only perceive sounds above 90 (dB). Some individuals with profound deafness cannot detect any sound at any decibel level.
How to Improve the Quality of Life of Deaf Persons
Persons with hearing impairments face a myriad of challenges, unlike those without disabilities. However, we can adopt ways to mitigate the impact of disabilities on their quality of life. These ways include:
1. Massive sensitization campaigns
Sensitization campaigns will help to create awareness about deafness in society. Such an initiative will also help persons without disabilities know what they can do to facilitate the inclusivity of deaf persons.
2. Promoting the use of sign language
The Kenyan Constitution recognizes Kenyan Sign Language (KSL) as an official language. However, its uptake is still wanting. The use of the language is mainly limited to environments that have a concentration of deaf persons. This limited uptake leads to a communication barrier between deaf persons and persons without disabilities.
The government should ensure that every person has basic KSL skills. This goal is achievable by incorporating the language in the Kenyan education curriculum. Such a measure will go a long way in promoting persons with hearing impairments inclusivity.
3. Enforcing Compliance with Article 54 of the Kenyan Constitution
Article 54 of the Kenyan Constitution outlines the rights of persons with disabilities. The Article entitles such people to use the appropriate means of communication. It also permits them to access materials and devices to help overcome the constraints arising from their disability.
This provision grants people with hearing impairment the right to an interpreter, braille, and sign language. However, despite this constitutional guarantee, persons with hearing impairments hardly enjoy these rights. For instance, hospital visits are usually unpleasant for deaf persons because many healthcare workers are not proficient in sign language, and no interpreters are available. The government should enforce this constitutional provision and require both the private and public sectors to offer these services to persons with hearing disabilities where and when necessary.