Download Hearing - ABBEE Hearing Solution

About Hearing
Hearing is one of the 5 senses which is an important and integral part of our lives. In
simple terms hearing is nothing but the Act of perceiving sound.
To put it scientifically this is what happens when we hear :
Sound vibrations travel through air, water, or solids in the form of sound waves. These
waves are captured by the pinna of the outer ear and transmitted through the auditory
canal to the eardrum.
The eardrum vibrates in response to the pressure of the sound waves. The initial
vibration causes the eardrum to be pushed inward by an amount equal to the intensity
of the sound, so that loud sounds push the eardrum inward more than soft sounds.
Once the eardrum is pushed inward, the pressure within the middle ear causes the
eardrum to be pulled outward, setting up a back-and-forth motion.
The movement of the eardrum sets all three ossicles in motion. The vibrating pressure
of the stirrup (last ossicle) on the small opening leading to the inner ear sets the fluid in
the cochlea in motion. The fluid motion causes a corresponding, but not equal,
wavelike motion of the basilar membrane.
When the basilar membrane moves, it causes the small hairs on the top of the hair cells
of the Corti to bend. The bending of the hair cells causes chemical actions within the
cells themselves, creating electrical impulses in the nerve fibers attached to the bottom
of the hair cells. The nerve impulses travel up the auditory nerve to the brain. Loud
sounds cause a large number of hair cells to be moved and many nerve impulses to be
transmitted to the brain.
The ear is the organ that detects sound. It not only receives sound, but also aids in balance
and body position.
Often the entire organ is considered the ear, though it may also be considered just the
visible portion.
As depicted in the image, Ear can be anatomically classified into Outer Ear, Middle Ear &
Inner Ear
Outer Ear
The outer ear collects external sounds and funnels them through the auditory system.
The outer ear is composed of three parts, the pinna (or auricle), the auditory canal, and the
eardrum (tympanic membrane).
Middle Ear
The middle ear transmits sound from the outer ear to the inner ear. The middle ear
consists of an oval, air- filled space approximately 0.1 cubic inch (2 cubic centimeters) in
volume.
Contained in this space are three tiny bones called ossicles (pronounced OS- si- kuls).
Because of their shapes, the three ossicles are known as the hammer (malleus), the anvil
(incus), and the stirrup (stapes).
Inner Ear
The inner ear is responsible for interpreting and transmitting sound and balance
sensations to the brain.
The inner ear is small (about the size of a pea) and complex in shape.
DIFFERENT TYPES OF HEARING LOSS
Losing the ability to hear or hear properly is hearing loss.
It can be resultant of various things such as constant exposure to loud sound, mishap,
chemical reactions, defects during birth and last but not the least by normal process of
ageing.
There are three different types of Hearing Loss
a) Conductive Hearing Loss
b) Sensorineural Hearing Loss
c) Mixed Hearing Loss
Conductive Hearing Loss
This impairment is a result of sound not reaching the inner ear ( i.e. Cochlea ).
This is caused by the blockage or damage in the outer and/or middle ear.
Some of the common cause for the same are ax build- up, a perforated ear drum, fluid in
the middle ear, or damage to the bones in the middle ear
Sensorineural Loss
This impairment is a result of dysfunction of the inner ear, the Cochlea ( Sensory part ) or
the hearing nerve ( Neural part )
Mixed Hearing Loss
Mixed hearing loss is a combination of conductive and Sensorineural hearing loss.
This happens when there is a problem in both the conductive pathway ( i.e. Outer &
Middle Ear) and in the Nerve Part ( Inner ear )
GENERAL REASONS FOR HEARING LOSS
a) Age
b) Exposure to Noise
c) Genetic Transmission
d) Disease / illness
e) Neurological Disorders
f) Chemical Reaction
g) Physical Trauma
h) Accidents involving injury to Head
SYMPTOMS OF HEARING LOSS
As our hearing pattern and sharpness changes gradually – many a times we would not
notice it and postponement in knowing the problem will only worsen things :
Listed below are a few indicators that you may potentially have a hearing loss:
● Have you been told that you are watching the television or listening to the radio
in a volume that is discomforting to others?
● Do you find it difficult when people are conversing in a slightly lower tone?
● Do you find it difficult to follow conversations on the telephone?
● Are you getting into the habit of asking people to repeat things because you are
unable to follow them ?
● Do you have difficulty following conversation in groups when more than one
person may be talking at the same time?
● Do you often mishear what others say or think that somebody has said
something different?
● Has anyone close to you indicated or you yourself have felt that your hearing
ability has deteriorated?
● Do you find it harder to hear clearly what others are saying if there is background
noise, such as in restaurants, public places, exhibitions etc
IMPACT OF HEARING LOSS
Losing the ability to hear or hear properly is bound to have various repercussions on
many aspects of One’s life.
It can drain out the person :
a) Emotionally
b) Physically
c) Mentally
Hence it is not unusual to see that people with hearing problems have difficulty in all
aspects of life and it may lead to depression as well.
DEGREES OF HEARING LOSS
Different Degrees of Hearing Loss
Mild hearing loss
Soft noises are not heard. Understanding speech is difficult in a loud environment.
Moderate hearing loss
Soft and moderately loud noises are not heard. Understanding speech becomes very
difficult if background noise is present.
Severe hearing loss
Conversations have to be conducted loudly. Group conversations are possible only with a
lot of effort.
Profound hearing loss
Some very loud noises are heard. Without a hearing aid, communication is no longer
possible even with intense effort
Key Facts about Hearing Loss
● 360 million people worldwide have disabling hearing loss
● Hearing loss may be inherited, caused by maternal rubella or complications at birth,
certain infectious diseases such as meningitis, chronic ear infections, use of
ototoxic drugs, exposure to excessive noise and ageing.
● Half of all cases of hearing loss are avoidable through primary prevention.
● People with hearing loss can benefit from devices such as hearing aids, assistive
devices and cochlear implants, and from captioning, sign language training,
educational and social support.
● Current production of hearing aids meets less than 10% of global needs
● Studies also showed that only one in five people who would benefit from a hearing
aid actually uses
●
● On average, people with hearing loss wait almost 10 years before they do
something about it.