Hearing is an important part of healthy living. The ability to hear contributes greatly to our physical and emotional well-being. When there is any partial or total inability to hear, it is called hearing impairment or hearing loss. It is a hidden disability or disorder that has a detrimental effect on the quality of life of an individual and those associated with him/her.
The auditory system can be divided into three parts. The outer ear consists of the pinna (the structures we see on the sides of the head), the ear canal, and the eardrum (tympanic membrane). The middle ear comprises the small bones (ossicles) that transmit sound from the outer to the inner part of the ear. The end-organ of hearing (cochlea), balance mediating system (vestibular system), and the hearing nerve (vestibular-cochlea nerve) form the inner ear. If any of these parts do not work properly, it may lead to the following types of hearing losses;
Conductive hearing loss– Problems with the conduction of sounds to inner ear caused by obstructions in the outer or middle ear leads to this type of loss.
Sensorineural hearing loss – A loss due to the problem in the inner ear or nerve is called the sensorineural hearing loss.
Mixed hearing loss – When both, conductive and sensorineural components cause a hearing loss, it is the mixed type.
Hearing loss can also be described as:
unilateral/ bilateral – Unilateral hearing loss is when one ear is affected and bilateral is when both ears are affected.
symmetrical/ asymmetrical- When there is an equal amount of hearing loss in both ears, it is referred to as ‘symmetrical’. When the loss on either side is unequal, it is asymmetrical.
progressive/ sudden – When the hearing loss is worsening, it is labeled as ‘progressive’. When there is a sudden drop in thresholds that leads to hearing impairment, it is referred to as ‘sudden’.
fluctuating/ stable- A transient change in hearing levels causes a ‘fluctuating hearing loss. When the hearing loss does not change, it is called stable.
congenital/ acquired – A congenital hearing loss is caused by an impairment that is present at birth. The acquired type is the one that a person acquires later in life.
prelingual/ postlingual – When a child develops a hearing loss before the acquisition of language abilities, it is called a ‘prelingual loss’. ‘Postlingual hearing loss’ refers to the type that affects individuals post language acquisition.
The most common causes include: Genetics, ageing, noise exposure, infections, trauma, birth complications, toxicity.
Effects & Complications
- Hearing loss is most often associated with cognition. The risk of being affected by Alzheimer’s disease or Dementia escalates with an increase in hearing thresholds. The redistribution of the brainpower caused due to alteration of the brain structures is usually the first link to Alzheimer’s disease and Dementia.
- Social isolation is one of the worrying effects of hearing loss. Withdrawal, depression, anxiety, and paranoia are other problems that stem from isolation. This leads to a decrease in health-related quality of life. Moreover, the lesser use of the brain due to withdrawal causes a quick decline in cognitive functions.
- Another detrimental effect of hearing loss is on the speech and language abilities of an individual (especially in children). Pre-lingual hearing losses have been identified as one of the major causes of delayed speech and language acquisition in children. A post-lingual hearing loss may require individuals with hearing impairment to make several adjustments or adaptations for living independently. Hearing impairment also causes a reduction in the feedback of their own speech/ voice in individuals, leading to speech and voice problems.
Prevention and Precaution
Half the time, hearing loss or risk of hearing impairment can be avoided through public healthcare measures like – immunization, proper care during pregnancy, appropriate medication with proper medical advice, and avoiding noise exposure/ limiting the use of personal audio systems.
Early identification and early intervention are strategies used to minimize the impact of hearing impairment, especially in children.
When in doubt, go to the right professional for help. An Audiologist is a healthcare professional, hearing specialist who will diagnose and rehabilitate hearing-related issues. An ENT specialist will medically treat hearing-related issues through surgery and drugs. A well-informed team of ENT and audiologists can be sought for any hearing-related issues.