Hearing Loss

Hearing Loss

Ears are sensitive organs. Our hearing system is unique as it completely mechanical. Our sense of smell, vision and taste involve chemical reactions. It is only our sense of hearing that is based on physical movements only. When an object produces sound, it travels in the air and vibrates the air particles. Vibrating particles are carried in the form of “pulses of vibrations” to our ears. This pulse of vibration is known as a sound wave. The ear sends these waves to the brain which interprets them.

Now, a person who is suffering from hearing loss, does not catch these sound waves at all.

The human ear is basically divided into three parts that lead to the brain. These are:

 

 

The Outer Ear- The outer ear consists of pinna and the ear/auditory canal. Sound waves are captured by the outer ear and sent to the eardrum via ear canal. The pinna helps determine the direction from where the sound is coming.

The Middle Ear- At the end of the ear canal, is the eardrum. This is where the middle ear starts. It has three bones called “ossicles”.The sound waves make these ossicles move up and down. The movement can be fast or slow depending in the pitch of the sound wave. This movement sends the signal to the inner ear.

The Inner Ear- The inner ear turns sound waves into sounds our brain can understand. The part in our ear that makes this happen is called the cochlea. When the fluid in your inner ear starts to move hair cells are triggered.Different hair cells move for different sounds. The hair cells change the movement into electrical signals. These signals go through the auditory nerve into the brain.

When any part of the hearing path is damaged, sound information cannot be properly carried to the brain. This results in some degree of hearing loss. The most common causes of hearing loss are noise and ageing. In most cases a hearing loss cannot be cured and is typically treated with hearing aids.

 

The type of hearing loss are generally classified as sensorineural, conductive and mixed hearing loss.

Sensorineural Hearing Loss (SNHL)

This type of hearing loss is due to the problems in the inner ear. This is the most common type of hearing loss, and more than 90% of people with hearing loss have SNHL. Patients usually have  difficulty with sound volume and clarity. especially Understanding speech becomes difficult. Sounds may seem muffled, and people may seem to mumble.

 

Causes:

Illness, Drugs that are toxic to hearing, Hereditary disorder, Aging, Head trauma, Malformation of the inner ear, Exposure to loud noise, Nerve tumors

Symptoms:

Difficulty in following conversations, Muffled sounds, Inability to hear when there is background noise , Difficulty hearing high-pitched sounds, Dizziness, Balance problems

Conductive Hearing Loss

Conductive hearing loss occurs when there is a blockage in the outer inner ear. Sounds cannot  get from the outer ear, to the eardrum and tiny bones (ossicles) of the inner ear.For someone with this type of a hearing loss, it may be much harder to hear faint sounds, and loud sounds might not seem as loud. 

 

Causes:

Malformation of outer ear, ear canal, or middle ear structures, Fluid in the middle ear, Ear infection, Allergies, Hole in the eardrum, Benign tumors

Symptoms:

Difficulty in hearing low pitched sounds, Loud noises do not seem as loud as they are

Mixed Hearing Loss

This happens if there is a damage to the outer or middle ear as well as the cochlea or auditory nerve in the inner ear.

 

Causes:

Anything that causes a conductive hearing loss or SNHL can lead to a mixed hearing loss.

Symptoms:

Difficulty in following conversations, Difficulty hearing high-pitched sounds