Hearing Process and Prevention of Hearing Loss

Image Source: Britannica

Hearing, or auditory perception is the ability to perceive sounds by detecting vibrations, changes in the pressure of the surrounding medium through time, through an organ such as the ear.

The ear is divided into three main parts – the outer ear, the middle ear, and the inner ear.

How the sound travels through the ear

• Sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum.

•  The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are called the malleus, incus, and stapes.

• The bones in the middle ear increases the sound vibrations and sends them to the cochlea, a snail-shaped structure filled with fluid, in the inner ear. An elastic partition runs from the beginning to the end of the cochlea, splitting it into an upper and lower part.

• Once the vibrations cause the fluid inside the cochlea to ripple, traveling waveforms along the basilar membrane. Hair cells near the wide end of the snail-shaped cochlea detect higher-pitched sounds, such as an infant crying. Those closer to the center detect lower-pitched sounds, such as a large dog barking.

•   As the hair cells move up and down, microscopic hair-like projections (known as stereocilia) that perch on top of the hair cells bump against an overlying structure and bend. Bending causes pore-like channels, which are at the tips of the stereocilia, to open up. When that happens, chemicals rush into the cells, creating an electrical signal.

• The auditory nerve carries this electrical signal to the brain, which turns it into a sound that we recognize and understand.

Types of hearing loss

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There are three types of hearing loss — sensorineural hearing loss, conductive hearing loss, and mixed hearing loss.

•       Sensorineural hearing loss: Sensorineural hearing loss is the most common type of hearing loss. It occurs when the inner ear nerves and hair cells are damaged — perhaps due to age, noise damage, or something else.

•       Conductive hearing loss: Conductive hearing loss is typically the result of obstructions in the outer or middle ear — perhaps due to fluid, tumors, earwax, or even ear formation.

•        Mixed hearing loss: Mixed hearing loss is just what it sounds like — a combination of sensorineural and conductive hearing loss.

Causes of hearing loss

Hearing loss is caused by many factors, most frequently from natural aging or exposure to loud noise. The most common causes of hearing loss are:

•       Aging

•       Noise exposure

•       Head trauma

•       Virus or disease

•       Genetics

•       Ototoxicity

Symptoms

Signs and symptoms of hearing loss may include:

•        Muffling of speech and other sounds

•        Difficulty understanding words, especially against background noise or in a crowd

•        Trouble hearing consonants

•        Frequently asking others to speak more slowly, clearly, and loudly

•        Needing to turn up the volume of the television or radio

•        Withdrawal from conversations

•        Avoidance of some social settings

When to see a doctor

If you have a sudden loss of hearing, particularly in one ear, seek immediate medical attention. Talk to your doctor if difficulty hearing is interfering with your daily life. Age-related hearing loss occurs gradually, so you may not notice it at first.

Ways to prevent hearing loss

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•        Avoid loud noises- The best way to avoid noise-induced hearing loss is to keep away from loud noise as much as you can.

•        Take care when listening to music- Listening to loud music through earphones and headphones is one of the biggest dangers to your hearing.

•        Protect your hearing during loud events and activities- To protect your hearing during loud activities and events (such as at nightclubs, gigs, or sports events)

•        Take precautions at work- If you’re exposed to loud noises through your work, speak to your human resources (HR) department or occupational health manager.

•        Get your hearing tested-Get hearing test as soon as possible if you’re worried you might be losing your hearing. The earlier hearing loss is picked up, the earlier something can be done about it.

Written By - Violet Priscilla S

Edited By - Anamika Malik