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Diagram of the human Ear
Outer Ear - The outer ear is the external portion of
the ear, which consists of the pinna, concha, and
auditory meatus. It gathers sound energy and
focuses it on the eardrum. The visible part is called
the pinna. It is composed of a thin plate of yellow
elastic cartilage, covered with integument, and
connected to the surrounding parts by ligaments
and muscles. The concha is the deep, bowl-shaped
part of the ear cartilage that attaches directly to the
side of the head at the front of the mastoid process
of the skull. The opening to the auditory canal is
located in the lower front corner of the concha. The
concha helps funnel sound into the auditory canal.
The auditory meatus (ear canal) is a tube running
from the outer ear to the middle ear.
Middle Ear - This is a small air-filled space on the
inside of the eardrum. There are 3 tiny bones called
ossicles in this part. They are called the hammer,
anvil and stirrup. They are contained within the
middle ear space and serve to transmit sounds from
the air to the fluid-filled cochlea.
Inner Ear- The inner ear consists of the cochlea,
vestibule, and semi-circular canals. The cochlea
propagates these mechanical signals as waves in
fluid and membranes, and finally transduces them to
nerve impulses which are transmitted to the brain.
The vestibule is the central part of the osseous
labyrinth, and is situated medial to the tympanic
cavity, behind the cochlea, and in front of the
semicircular canals. In the middle ear, the energy of
pressure waves is translated into mechanical
vibrations. The semicircular canals are three halfcircular, interconnected tubes located inside each
ear. They send messages to your brain to help you
keep your balance when you move.
Description of how the human ear
works
The ear is a key organ of the auditory system that helps in detecting and perceiving sound waves. The parts
of the ear turn sound waves into vibrations which are then translated into nerve messages that are sent to
the brain. Sound travels into the ear from the external ear. The external ear, or outer ear, is the part of the
ear that is visible plus the ear canal. Sound enters the ear through the outer ear and travels to the eardrum.
The sound waves cause the eardrum, also called the tympanic membrane, to vibrate. These vibrations pass to
the middle ear. The sound vibrations are delivered by a part of the middle ear called the stapes. The inner
ear translates the vibrations into nerve messages that are delivered to the auditory nerve which rests at the
base of the cochlea. The auditory nerve, named the eighth nerve, carries these messages to the brain, which
interprets the impulses as sound.
Description of the human frequency
response and how it compares to
another animal
The number of vibrations that are produced per
second is called frequency. Frequency varies for
each sound and is measured in hertz. One hertz is
equal to one vibration per second. A sound with a
low frequency will have a low pitch and a sound with
a high frequency will have a high pitch. The range of
hearing for a healthy young person is 20 to
20,000 hertz. The hearing range of humans gets
worse with age. People lose the ability to hear
sounds of high frequency as they get older.
Dog's sense of hearing has an important role within
their world. Not only do dogs have a highly
developed sense of hearing that can hear a wide
range of sounds but they also have the ability to pin
point the exact cause of the sound, discriminate
between sounds, make an accurate interpretation of
the sound, and decided whether it is threatening or
non-threatening. The frequencies that dogs can
perceive and hear are almost twice that of humans
and they can pick up and distinguish sounds at
roughly 4 times the range of humans. For example a
sound that you can hear at 20 meters a dog can
detect pinpoint and interpret at 80 meters. Dogs
also have the ability to hear ultra high frequencies
that humans cannot and many professional dog
handlers and trainers use this ability to their
advantage by teaching them and training them to
respond to different commands given on whistles
that produce ultra high frequency sounds.
Two problems that occur with human
hearing
Hearing loss:
Hearing loss means total or partial hearing inability
in one or both ears. It may be temporary or
permanent. There are different types of hearing loss
such as conductive hearing loss, sensor neural
hearing loss, functional hearing loss, central hearing
loss and mixed hearing loss. The main causes of
hearing loss are ear infections, damage to ear,
aging, genetic conditions like hereditary nephritis,
as well as some congenital factors like fetal iodine
deficiency effects and premature birth.
Temporary hearing loss is due to an exposure to
loud sounds, ear blockage due to accumulation of
ear wax, middle ear infections and damage to the
auditory nerve in the brain or the sensory
structures of the inner ear due to infections, tumors
or skull injuries. Sudden hearing loss is caused by
trauma, certain infectious diseases, neurological
causes like multiple sclerosis, abnormal tissue
growth, circulatory problems in the inner ear and
certain medications like birth control pills.
Otitis externa: Infection of external ear is known as
otitis externa or swimmer’s ear. It is mainly caused
by bacteria, or sometimes by fungi. Excess moisture
in the ear due to swimming or humid weather makes
the ear more vulnerable for bacterial infection.
Frequent swimming, accumulation of ear wax and
skin allergies are the risk factors for otitis externa.
It causes severe pain, itching, swelling and redness
in the outer ear.
Technological advancement in treating
hearing problems
Without a doubt, the ability to hear and see are two major factors in our quality of life. Hearing loss affects
our ability to communicate, sense our surroundings, and enjoy many forms of entertainment.
Miniaturization – Hearing aids take full advantage of miniaturization, making hearing aids nearly invisible and
more comfortable. All modern aids now utilize microchips with advanced computer programming. It is now
quite common to find companies that offer custom-made hearing aids tailored to a patient's specific needs.
Digital Signal Processing - Technological advances also allow sounds to be processed instantaneously
through digitization. Digitization converts sound to data. Data can then be filtered, altered, or have complex
algorithms applied to it before it is converted back to sound again. For example, a patient trying to converse
with another person on a busy street will have difficulty hearing that person because of background noise. By
processing the sound digitally, the background noise can be reduced while the voice is enhanced, resulting in
improved clarity
LASIK - LASIK (laser-assisted in situ keratomileusis) is a highly advanced surgical procedure that corrects
vision by reshaping the cornea (the clear, curved membrane on the front of the eye) using a computercontrolled laser. The process involves a standard vision correction test, exactly like that used for
determining corrective lenses for glasses or contacts, and a corneal map, which is created by projecting
concentric rings of light on the cornea