Assistive Technology Project

Presented By: Rose Aldan

Hearing Aid

How Your Ear Works

• An auditory wonder

• Your ears appear to be relatively simple structures. But they are, in fact, only part of the complex auditory system — passageways, vibrating structures, nerves and specialized areas of the brain that work together to gather and interpret sound.

• In people with normal hearing, the ears can detect a child's whisper or a crack of thunder, the single call of a songbird or the entire range of instruments in an orchestra.

How You HearThe ear is made up of three primary parts: the outer ear, middle ear and

inner ear. Each section is composed of structures that play distinct roles in the process of converting sound waves into

signals that go to the brain.

Outer EarThe outer ear is composed of the

visible part of the ear (pinna), the ear canal and the eardrum. The

cup-shaped pinna (PIN-uh) gathers

sound waves from the environment and directs them into the

ear canal. When a sound wave strikes

the taut, but somewhat flexible eardrum (tympanic

membrane), the eardrum vibrates.

Middle EarThe middle ear is an air-filled cavity that

holds a chain of three bones: the hammer,

anvil and stirrup. The middle ear is

connected to the back of your nose and

upper part of your throat by a narrow channel called the auditory tube, or

eustachian tube. The tube opens and closes at the throat-end to refresh the air in the

middle ear, drain fluids and equalize pressure in the ear.

Equal pressure on both sides of the eardrum is important for normal

vibration of the eardrum.

Bones of the Middle Ear

The middle ear contains three tiny bones, including the:-Hammer (malleus), which is attached to eardrum.-Anvil (incus), which is in the middle of the chain of bones.-Stirrup (stapes), which is attached to the oval window, the membrane-covered opening to the inner ear.The vibration of the eardrum triggers a chain of vibrations through the bones. Because of differences in the size, shape and position of the three bones, the force of the vibration increases by the time it reaches the inner ear. This increase in force is necessary to transfer the energy of the sound wave to the fluid of the inner ear.

Inner EarThe inner ear contains

a group of interconnected, fluid-filled chambers. The

snail-shaped chamber, called the cochlea

(KOK-le-uh), plays a role in hearing. Sound

vibrations from the bones of the middle

ear are transferred to the fluids of the

cochlea. Tiny sensors (hair cells) lining the cochlea convert the

vibrations into electrical impulses that are transmitted along the auditory nerve to

your brain.

Inner EarThe other fluid-filled

chambers of the inner ear include three tubes called the

semicircular canals (vestibular

labyrinth). Hair cells in the semicircular canals detect the

motion of the fluids when you move in any

direction. They convert the motion

into electrical signals that are transmitted along the vestibular nerve to the brain.

This sensory information enables you to maintain your

sense of balance.

Traveling to the Brain

Electrical impulses travel along the

auditory nerve and pass through several

information-processing centers. Signals from the right ear travel to

the auditory cortex located in the temporal lobe on the left side of the brain. Signals from

the left ear travel to the right auditory cortex.The auditory cortices

sort, process, interpret and file information

about the sound. The comparison and

analysis of the all the signals that reach the

brain enable you to detect certain sounds and suppress other

sounds as background noise.

Hearing LossIn 90 percent of cases, hearing loss results from damage to the hair cells

in the cochlea, the National Institutes of Health says. This is called "sensorineural hearing loss." The damage can occur as a result of genetic

factors, aging, illness, certain medications and exposure to loud noise. When the hair cells in the inner ear are damaged, electrical signals are

not transmitted as effectively. This causes impaired hearing. Sensorineural hearing loss is the main type of hearing loss that can be

"reversed" with a hearing aid.

What is a Hearing Aid and How does it Work?

All hearing aids consist of a microphone, an

amplifier, a miniature loudspeaker, or receiver, and a tiny battery. The

microphone catches sounds and transforms

them into electrical impulses. The amplifier modulates the electrical

signals. Finally, the receiver converts the amplified signals into sounds and transfers

them into your ear canal. Although the basic

components of all hearing aids are the same,

hearing aids differ in design, amplification

technology and special features.

Why Wear A Hearing Aid

Hearing problems might restrict your daily activities. You might have trouble communicating and following instructions in school or at work. When damage to the inner ear is the cause of your hearing loss, you

don't have to struggle through life because you can't hear. A properly fitted hearing aid might make sounds easier to hear. An audiologist or

otolaryngologist can help you determine which type of hearing aid would be best for your condition.

Why People Don’t Wear Hearing Aids

Some people don't want a hearing aid because they think it is too expensive. Others feel it is embarrassing to wear one because

they associate it with old age, low intelligence or disability. This is odd when you think about it, as many of the same people happily

wear vision aids, such as contact lenses or glasses. Shunning hearing aids to avoid looking old can be self-defeating. If you

have trouble hearing, your conversation partners might think of you as old or unfriendly. There is nothing embarrassing about wearing a hearing aid, and people most likely won't notice as

most hearing aids are so small that they are practically invisible.

CostHearing aids for

children cost between $1,000 and $4,000 per

ear. A few health insurance companies will pay for children

hearing aids, but most do not. Medicaid will

pay for children hearing aids for those

who qualify.

History of Hearing Aids

The first hearing aids were enormous, horn-shaped trumpets with a large, open piece at one end that collected

sound. The trumpet gradually tapered into

a thin tube that funneled the sound

into the ear.

The development of the modern hearing aid might not have been possible had it not been for the contributions of two of the

greatest inventors of the late 19th and early 20th centuries. Alexander Graham Bell electronically amplified sound in his

telephone using a carbon microphone and battery -- a concept that was adopted by hearing aid manufacturers. In 1886, Thomas

Edison invented the carbon transmitter, which changed sounds into electrical signals that could travel through wires and be

converted back into sounds. This technology was used in the first hearing aids

In the 1990s, hearing aids went digital. Sound quality improved and became more adjustable. Also during this

time, programmable hearing aids were introduced.

At the turn of the 21st century, computer technology made hearing aids smaller and even more precise, with settings

to accommodate virtually every type of listening environment. The newest generation of hearing aids can continually adjust themselves to improve sound quality

and reduce background noise.

History of Hearing Aids

Types of Hearing Aid’s

How Reliable are Hearing Aid’s

• Reliability and appropriateness are crucial when your hearing is at stake. Also remember that some prices include an evaluation and checkups.

• If they are well cared for, hearing aids should last for five to seven years. Most of the problems that send hearing aids in for repairs are caused by dirt, earwax and oil from the skin that blocks the microphones and receivers.

Accessibility in the CNMI• Commonwealth of the Northern Mariana

Islands Assistive Technology Project

• Department of Public Health

• Marianas Health Services

• Public School System

• Office of Vocational Rehabilitation

• Insurance

Sources

-Google Images

-Department of Public Health

-www.livestrong.com