- Tuesday, 24 December 2024
Hearing Loss: A Hidden Disability
Dr. Kripa Dongol
Hearing is an important function of the ears through which we perceive sounds from the surroundings. Hearing is essential for language development, communication, social well-being, employment and education attainment. Moreover, it is a sense which helps us to be engaged in recreational activities such as music and entertainment.
Hearing loss is often referred to as “a hidden or invisible disability” because the patients with hearing loss are often ignored, forcing them to remain silent and isolated most of the time.
The World Health Organization (WHO) has estimated that over 1.5 billion people have some degree of hearing loss and this figure could rise up to 2.5 billion by 2050. In addition, the WHO estimates that more than 1 billion young people are at risk of permanent hearing loss because of listening to loud music for a long duration. Globally, unaddressed hearing loss is the third largest cause of having to live for years with disabilities.
Preventable
With effective public health measures, many cases of hearing loss are preventable. If hearing loss occurs, different treatment modalities and rehabilitation therapies could minimize disabilities and handicaps. People with hearing loss could equally participate in education, employment and social activities if they get proper treatment and rehabilitation in time.
Hearing loss is often ignored by the person himself and by family, society and health authorities. It is largely for lack of awareness, because of unavailability of health facilities and because of poverty. Hearing loss could have detrimental effects not only on that person but also on the overall economic development of a country.
Hearing loss affects speech and language development, inter-personal communication, education, learning and job opportunities. A person with hearing loss is more likely to have low self-esteem, feel insecure and suffer from depression and anxiety. They are neglected and stigmatized in society.
Hearing loss could affect any age group, right from birth till old age. There are many causative factors for hearing loss such as genetic factors, infections, trauma, birth-related (perinatal) factors, age-related factors, ototoxic drugs and noise.
The adverse perinatal period could result in hearing loss in the newborn. Certain maternal infections during pregnancy, birth asphyxia, low birth weight, hyperbilirubinaemia, meningitis and prolonged neonatal intensive care unit (NICU) stay are some of the risk factors during the perinatal period.
Likewise, head injuries and direct trauma to the ear could lead to hearing loss. Different drugs such as antimalarials, aminoglycosides, salicylates and anticancer drugs can also cause hearing loss.
Infection of the middle ear, commonly called otitis media, is an important preventable cause of hearing loss in our country. Most ear patients suffer from ear discharge and hearing loss. If treated in the early stages, these patients could have a good hearing outcome. Children with otitis media may have delayed speech and language development with poor school performance.
Therefore, early treatment is essential. Various problems associated with otitis media are perforation of the ear drum, collection of fluid inside the middle ear, cholesteatoma (which has bone destroying properties) and ossicular discontinuity, to mention just a few.
These patients usually have slowly progressive hearing loss. However, many of them ignore this problem and visit health facilities when the disease has reached the advanced stages.
It is important to note that treatment at the earliest possible stage could restore hearing. Another important infective cause of hearing loss is meningitis, which needs early medical intervention.
Around 250 genes have been found to be responsible for causing hereditary hearing loss. The patients may show certain symptoms. Most of them are born with hearing loss but some may develop progressive hearing loss. Genetic hearing loss is manifested most often in children born of consanguineous marriages (between close biological relatives). Genetic counselling helps prevent this type of hearing loss.
Priority
It is estimated by the Global Burden of Disease that 65% of people aged over 60 years of age experience some degree of hearing loss and 25% of them have moderate to high hearing loss. Various factors such as exposure to loud sounds, ototoxic drugs, chemicals and smoking, along with genetic susceptibility, play a role in the development of age-related hearing loss.
Age-related hearing loss is a significant cause of depression, social isolation and dementia in the elderly population. Therefore, prevention of the onset of hearing loss and rehabilitation must be a priority for them.
Exposure to loud sounds may be due to occupation, recreational activities or environmental sounds. Loud sounds could permanently damage the organ of hearing (cochlea). The maximum permissible sound level is 85 dB for a duration of 8 hours in an occupational setting. Listening to loud music, prolonged use of ear-phones, loud car honks and machinery noise can cause noise- induced hearing loss.
It is estimated that 60 per cent of hearing loss is preventable with effective public health measures. Various strategies for the prevention of hearing loss include immunization, care during pregnancy and birth, neonatal hearing screening, genetic counselling, early identification and treatment of ear pathologies, safe listening practices, reduction of noise exposure at the workplace and rational use of ototoxic drugs.
Vaccination against rubella, mumps and measles is an effective measure for preventing hearing loss. Similarly, immunization against Pneumococcus and Haemophilus influenzae type B have reduced the incidence of hearing loss secondary to meningitis and otitis media.
Occupational noise-induced hearing loss could be prevented by making workers aware about the effects of noise on hearing, encouraging them to use ear plugs and conducting hearing surveillance. Noise level generation could be controlled at the workplace with strict enforcement of the required legislation.
Hearing screening of neonates, school-going children, adults taking ototoxic drugs, people at risk of noise-induced hearing loss and older adults would help in the early identification of hearing loss. In most of the developed countries, universal hearing screening of the newborn is performed with the aim of the early identification of hearing loss and for medical intervention. However, in Nepal, there are only few centers where newborn hearing screening is being performed. In schools, teachers should identify inattentive children, children with learning difficulties and children with poor school performance, and refer them to an ENT doctor.
Ear Care Awareness
Public awareness about ear care helps prevent many ear problems. Instillation of oil into the ears, swimming in dirty water and use of matchsticks, ear buds, feathers or sharp instruments to clean the inside of the ears must be avoided. These habits could result in perforation of the ear drum, trauma to the ear canal and impaction of earwax and foreign bodies in the ears. Dissemination of such information among the public can help reduce ear pathologies.
Patients with otitis media could be managed medically or surgically. It is essential to address such problems at the earlier stages of the disease to restore hearing. Other rehabilitation options are hearing aids, cochlear implants, bone conduction hearing devices and middle ear implants.
Many patients require speech therapy simultaneously. Communication with such patients will be easier if they are trained in lip reading. Some patients use sign language for communication. Recently, there has been development of hearing assistance technologies to aid in communication. They include assistive listening devices and alerting devices.
“Blindness cuts us off from things, but deafness cuts us off from people” is a poignant quote by Hellen Keller, which only a person with hearing loss can perceive. We should encourage people with hearing problems to seek help from ENT doctors and prevent them from being stigmatized.
Early detection and intervention are the key to solving the problems of hearing loss. The government should develop and implement effective public health strategies to prevent hearing loss and to rehabilitate the hearing-loss patients.
(The author is assistant professor at Department of ENT,Teaching Hospital)
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