HEARING IMPAIRMENT

 

Hearing impairment is a condition where individual has partial or total inability to hear. A person who is not able to hear, as well as someone with hearing thresholds of 20 dB or better in both ears – is said to have hearing loss. Hearing loss may be mild, moderate, severe, or profound. It can affect one ear or both ears, and leads to difficulty in hearing conversational speech or loud sounds. However, hearing impairment in children may affect the development of language and can cause work related difficulties for them in future. Hearing loss is caused by many factors, including: genetics, age, exposure to noise, illness, chemicals and physical trauma.  According to World Health Organization, Over 5% of the world’s population (430 million people) requires rehabilitation to address their ‘disabling’ hearing loss (432 million adults and 34 million children). It is estimated that by 2050 over 700 million people or one in every ten people, will have disabling hearing loss.

Hearing loss can also be classified based on which portions of the hearing system (auditory system) are affected. When the nervous system is affected, it is referred to as sensor neural hearing loss. When the portions of the ear that are responsible for transmitting the sound to the nerves are affected, it is referred to as conductive hearing loss.

People who are hard of hearing usually communicate through spoken language and can benefit from hearing aids, cochlear implants, and other assistive devices as well as captioning while 'Deaf' people mostly who have profound hearing loss, which implies very little or no hearing often use sign language for communication.

The following are some of the causes of hearing impairment during critical periods in life.

Prenatal Period

• Genetic factors - Include hereditary and non-hereditary hearing loss

Perinatal period

• Birth asphyxia (a lack of oxygen at the time of birth
• Low-birth weight

Childhood and adolescence

• Chronic ear infections (chronic suppurative otitis media)
• Collection of fluid in the ear (chronic nonsuppurative otitis media)
• Meningitis and other infections

Adulthood and older age

• Chronic diseases
• Smoking
• Otosclerosis
• Age-related sensor neural degeneration
• Sudden sensor neural hearing loss

WHO estimates that unaddressed hearing loss poses an annual global cost of US$ 980 billion. This includes health sector costs (excluding the cost of hearing devices), costs of educational support, loss of productivity, and societal costs. 57% of these costs are attributed to low- and middle-income countries.

Many of the causes that lead to hearing loss can be avoided through public health strategies and clinical interventions implemented across the life course. Prevention of hearing loss is essential throughout the life course from prenatal and prenatal periods to older age. In children, nearly 60% of hearing loss is due to avoidable causes that can be prevented through implementation of public health measures. Likewise, in adults, most common causes of hearing loss, such as exposure to loud sounds and autotoxin medicines, are preventable.