Deafness, hearing loss, or hearing impairment is a condition that causes partial or full loss of ability to hear a sound or spoken words. It can be mild, moderate, or severe depending on the rate of hearing sounds.
In some cases, a person can understand sounds when it is quite around him/her but can not hear or understand sounds when it is noisy outside. It can be a condition by birth, any accident or medical conditions.
What causes deafness?
It can be caused by mumps, cancer, meningitis, certain drugs, streptomycin- a medicine used for the treatment of tuberculosis, chickenpox, Lyme disease.
The inner ear contains some of the most delicate bones of our body and damage to them can cause deafness or partial hearing impairment.
Types of deafness
There are mainly three types..
Conductive hearing loss
It is a condition in which vibrations from the outer ear are not received by the inner ear. There can be multiple reasons for the same like a defect in the eardrum, severe ear infection, swelling in the eardrum, ear loaded with ear wax, defective ossicles.
Sensorineural hearing loss
This type of hearing loss is because of dysfunction of the inner ear, the cochlea, auditory nerve, or brain damage. This usually happens when hair cells in the cochlea get damaged. As an individual grows old, hair cells lose and cause deterioration in hearing.
This can also happen when ears are exposed to loud noises. This damage can never be replaced, research is going on to fix this issue.
Mixed hearing loss
As the name suggests, it is a mix of conductive and sensorineural hearing loss. Ear infections prevailing for a long time can damage both the eardrum and the ossicles. There are treatments for fixing the same, but it is not always effective.
Difference between hearing loss and deafness
Hearing loss – It is a condition in which a person suffers from partial hearing impairment. A person can hear loud noises but can not not slow noises. It is not the same hearing power again.
Deafness – It is a condition in which a person is unable to listen to any kind of noise. This can be by birth or any accident.
To summarize, hearing loss is partial hearing capabilities and deafness is a complete hearing loss.
How hearing works?
There are three bones in the ear that are ossicles in the middle ear. The vibrations which are caused by the sound waves enter the ear, slowly move down to the ear or auditory canal, and hit the eardrum and the three bones of the ear.
These ossicles amplify the vibrations, which are then picked up by small hair-like cells in the cochlea.
These move as the vibrations hit them, and the movement data is sent through the auditory nerve to the brain. The brain processes the data, which a person with functional hearing will interpret as sound.
Forms of deafness
There are two forms; unilateral and bilateral deafness.
It is a form of deafness in which a person is unable to recognize sounds from one ear. Another name for it is single-sided deafness.
People suffering from unilateral hearing impairment find it difficult to hear conversation if the other person is on their affected side. Figuring out the direction of the sound is also very hard for them. Understanding other people is a lot more difficult when there is a lot of noise.
Babies born with unilateral deafness tend to have developmental speech delays. It is very hard for them to concentrate and social activities are even harder.
Bilateral deafness is a condition in which a person is unable to hear sounds with both ears. It is also known as acute deafness.
Levels of deafness
There are four level of deafness.
Sound is measured in decibels (dB). A person suffering from mild deafness or mild hearing impairment can only listen to a sound between 25 to 29 decibels. They can not understand or recognize sounds when there is a lot of background noise.
An individual suffering from moderate deafness or moderate hearing impairment can only hear sound between 40 to 69 decibels. In this case, also background noises play an important role.
It is a condition in which a person is unable to hear sounds below 70 to 89 decibels. A person suffering from severe deafness usually communicates through sign language or lip read technique.
Profound deafness is a condition in which a person can not hear anything. They are typically deaf and use sign language or writing to communicate.
How it is diagnosed?
There is a physical examination to check whether everything is going well or not. In this examination doctor see the ear internally using an otoscope. Given below are the things which are examined through otoscope;
- Any blockage due to a foreign object
- The collapse of an eardrum
- Excess accumulation of earwax
- An infection in the ear canal
- An infection in the middle ear if a bulge is present in the eardrum.
- Cholesteatoma, a skin growth behind the eardrum in the middle ear.
- Fluid in the ear canal
- A hole in the eardrum
Treatment depends on the condition of the patient or severity of the problem. There is no cure to Sensorineural hearing loss. Some different treatments are listed below;
Hearing aids are the devices that assist hearing. Hearing aids come in different types, sizes, circuitries, and levels of power. These devices never deafness but amplify the sound that enters the ear so that the listener can hear more clearly.
Hearing aids consist of a battery, loudspeaker, amplifier, and microphone. Today, they are very small, discreet, background noise cancellation, and can fit inside the ear.
Hearing aids are not effective for a person with profound deafness. It is made on order according to the size of the ear and suitable auditory range.
Cochlear implant is a solution for the people with eardrum and middle ear functioning normally. This thin electrode is inserted into the cochlea. It stimulates electricity through a tiny microprocessor placed under the skin behind the ear.
Sign language and lip reading
People suffering from profound deafness are left with the solution of lip reading and sign language. Lip reading is a procedure in which the person read the lips of the other person and tries to understand what the other person wants to say.
Sign language is movement of hands as per the thought of the orator. People suffering from deafness are taught this language to communicate from other people.
Prevention and cure
There are following measures that may help protect hearing:
- TV, radio, music players, and toys: Do not set the volume too high. Children are especially sensitive to the damaging effects of loud music. Noisy toys can put children’s hearing at risk.
- Headphones: Focus on isolating the sounds you want to hear and blocking out as much environmental sound as is possible, instead of drowning it out with high volume.
- Occupational health: If you work in a noisy environment, such as discos, nightclubs, and pubs, wear earplugs or earmuffs.
- Leisure venues: If you go to pop concerts, motor racing, drag racing, and other noisy events, wear earplugs.
- Cotton swabs: Do not prod them into adult or infant ears. The same applies to Q-tips or tissues.