Hearing Loss: Causes, Diagnosis And Treatments Options

In the recent World hearing report by the World Health Organization (WHO), they have reported a prevalence deafness of varying degrees in approximately 1.5 billion people and south east Asian country including India as expected to have approximately 109 million cases. Losing an important human sensation- Hearing can impact a person ability to perceive sound around him, ability to communicate, ability to express thoughts and ability to learn and gain education. This can affect any age group. When a child is born deaf, screening the child for hearing loss plays an important role. Identifying a deaf child and appropriate habilitation can avoid adverse consequences of growing up with hearing such as delayed or lack of language development, impaired psychosocial wellbeing, loss of quality of life, difficulty in education and economic independence.

As for acquired hearing loss, many of conditions are preventable if diagnosed and treated appropriated at the right time. WHO has also reported that more than 1 billion young individuals are at the risk of developing hearing loss due cochlear damage secondary to acoustic trauma of hearing music at loud intensity for a prolonged period of time.

Unsplash/Representational Image

The past few decades have witnessed tremendous strides in the understanding the physiology of hearing and its related inventions and development of technology to diagnose as well as to restore hearing loss. These technologies have brought reinvigoration to a deaf person¡¯s life by giving them access to communication and there by enabling them to live their life to full potential.

What are the common causes of hearing loss?

Hearing loss can be Prelingual (before a person learn to speak) or postlingual (hearing loss after a person learns to speak). Majority of the prelingual hearing loss are due to genetic abnormalities (It can be inherited (running in families) or sporadic (new onset with no family history). The chances of these familial genetic inheritance increase with the practice of consanguineous marriages (marrying between the relatives). Other causes of prelingual hearing loss can be low birth weight, premature birth, neonatal jaundice, Maternal infection, meningitis (Infection affecting brain covering). Some of the causes are preventable with vaccination and right medical care. These children who have deafness have to be identified and habilitated at an early age, because the growing brain has a time limit after which the language development and communication skills fail to develop.

As for Post-lingual hearing loss, again can be genetic, meningitis, viral infection, age related hearing loss, ototoxicity (side effect of a lifesaving drug), ear infection, smoking, noise induced hearing loss, trauma, and conditions such as otosclerosis.

How to diagnose hearing loss?

Unsplash/Representational Image

With the advance in technology, we can now detect and assess the level of hearing loss in newborn and young children also. It is always ideal to know the hearing status of a new born child, as we have already understood the value to early intervention. Newborn screening is now routinely performed in most of the hospitals as. Newborn screening is a two-step screening program, where child is subjected to initial test called Otoacoustic emission testing (OAE), followed by Brainstem Evoked Response Audiometry (BERA). These are safe and reliable tests. If a child is found to have hearing loss in these tests, the child will be further evaluated to assess the reason for hearing loss and possible options for hearing habilitation.

As adults, there are various test to detect hearing loss, its severity and the cause of hearing loss. Ranging from simple clinical testing with tunning fork to cortical evoked response telemetry. Technology now allows to narrow down on the exact location of the pathology to execute personalized treatment.

What are the treatment options for hearing loss?

Based on the cause of hearing loss, treatment can be medical, hearing aids, surgical restoration or surgical implantation of hearing devices.

What is implantation otology?

Unsplash/Representational image

It a subspeciality of Otorhinolaryngology (ENT) which specializes for conditions related to hearing loss and deals with surgically placing a hearing device to restore hearing. There are various implantable devices, such as Cochlear implant, Bone anchored hearing device, Middle ear implants, totally implantable hearing devices, and Auditory brainstem implants.

Who are candidates for cochlear implant?

Cochlear implant is suitable to both children as well as adults with severe to profound hearing loss who are not benefited with conventional hearing aids. This is a first of its kind, an implantable bioprosthesis which has enabled human to bypass the cochlea (hearing organ) and stimulate nerve directly to mimic the natural hearing. This bioprosthesis has stood the test of time and has proven beyond doubt that it is a safe and effective method to restore sensorineural hearing loss. It has also shown to be effective for single sided deafness and also shown to be safe, with superior results with bilateral cochlear implantations.

Summary

Deafness is a silent disability which affects the quality of life of a person. Restoring hearing is of prime importance in prelingual as it¡¯s the important pedestal for language and speech development. Several conditions can lead to hearing loss. Hearing restoration can be achieved with various modality of treatment based on the etiology. Implantation otology is a specialty that deals with cases of hearing loss and provides restoration of hearing with the help of bio prosthesis such as cochlear implant, bone anchored implanted etc. Hearing loss can also be acquired in a normal individual due to unhealthy practices. Living healthy lifestyle and avoiding unnecessary exposure to loud intensity sounds can prevent development of hearing loss.

About the author: Dr. Sreenivas Kamath K is a Consultant in ENT, KMC Hospital, Mangalore. All views/opinions expressed in the article are of the author.