Deafness

What is deafness?

According to the World Health Organization (WHO), a person has hearing loss when they are not able to hear as well as someone with normal hearing, meaning when the hearing threshold in both ears is equal to or greater than 25 dB. Below 25 dB is considered normal hearing.

A person may have hearing loss without even realizing it. People of all ages gradually lose their hearing, often due to the natural aging process or prolonged exposure to loud noise.

Recently, genetic factors that predispose some individuals to hearing deterioration in adulthood have been identified. Other contributing factors include viral or bacterial infections, heart disease, diabetes, strokes, head trauma, tumors, and certain medications that are toxic to the auditory system. Treatment for hearing loss depends on the cause and how early it is diagnosed.

Scale / Classification

Hearing loss can be mild, moderate, severe, or profound, affecting one or both ears (unilateral or bilateral), and may cause difficulty hearing conversations or even loud sounds, depending on the degree of loss.

Difference Between Deafness and Hearing Impairment

People with hearing impairment have hearing loss ranging from mild to severe. They usually communicate through speech and benefit from hearing aids, cochlear implants, and other assistive devices, as well as captioning.

Cochlear implants are especially helpful for people with more severe hearing loss (severe to profound) who cannot achieve minimal speech understanding with conventional hearing aids.

People who are considered "deaf" often have profound hearing loss, meaning they hear very little or nothing at all. They usually communicate through sign language or use cochlear implants.

Types

Hearing loss can result from damage to any part of the peripheral or central auditory systems. It is therefore classified into conductive, sensorineural, mixed, and central types.

Conductive hearing loss results from obstruction or disease in the outer or middle ear, impairing the transmission of sound energy from the middle ear to the inner ear.

Sensorineural hearing loss results from failure in converting vibrations into neural impulses within the cochlea or in transmitting these impulses through the auditory nerve.

Mixed hearing loss involves a combination of both types, due to damage in both the middle and inner ear.

Central hearing loss refers to defects in the brainstem or higher-level auditory processing centers in the brain.

Causes

Congenital

Congenital causes can lead to hearing loss present at birth or acquired shortly after. Hearing loss may be caused by hereditary or non-hereditary genetic factors, or by certain complications during pregnancy and childbirth, including:

• maternal rubella, syphilis, or other infections during pregnancy
• low birth weight
• birth asphyxia (lack of oxygen at birth)
• improper use of specific medications during pregnancy, such as aminoglycosides, antineoplastic and cytotoxic drugs, antimalarials, and diuretics
• severe neonatal jaundice, which can damage the auditory nerve

Acquired

Acquired causes can lead to hearing loss at any age, such as:

• infectious diseases, including meningitis, measles, and mumps
• chronic ear infections
• fluid buildup in the middle ear (otitis media)
• use of certain medications, such as those used to treat infections, malaria, tuberculosis, and cancer
• head or ear injuries
• excessive noise exposure, including occupational noise from machinery or explosions
• recreational exposure to loud sounds, such as using personal audio devices at high volumes for long periods, and frequent attendance at concerts, nightclubs, bars, and sporting events
• aging, particularly due to degeneration of sensory cells
• earwax or foreign objects blocking the ear canal

What Can I Do to Improve My Hearing?

Eliminate or reduce unnecessary noise around you. Inform friends and family about your hearing loss and ask them to speak slowly and clearly. Ask people to look at you when they are speaking. Use sound amplifying devices on phones. Start using hearing aids as early as possible.

Tips for Maintaining Hearing Health

If you work in noisy environments or are frequently exposed to loud places like traffic or construction sites, choose quiet leisure activities instead of noisy ones. Use earplugs when exposed to noise for extended periods. Earplugs can reduce the volume of sound reaching the ear to a safer level. Avoid using multiple noisy machines at the same time. Keep the volume low on TVs, stereos, and headphones. Take care of your overall health.

By Einstein Editorial Board