Download Hearing Aids

Beatrix Jones
 How do hearing aids relay sounds to people?
 What are the parts of a hearing aid?
 Which type of hearing loss is the most common?
I chose the project because one of my best friends
has a hearing aid. When we were assigned a project
about sound and hearing, I thought it would be
fascinating to find out more about my friends’ condition
and how hearing aids help her. My goal is to find out
how hearing aids relay sounds to people and how they
are made.
 I saw that hearing aids are made out of 4 main parts:
 A microphone picks up sounds and sends it to the
amplifier.
 An amplifier makes sound louder and sends it to the
receiver.
 The receiver/speaker turns sound back into electrical
signals which are sent to the brain.
 A battery powers hearing aids.
 This is how hearing aids relay sound to people.
There are two ways people lose hearing.
 The first way is conductive hearing loss.
 Conductive hearing loss is when sound doesn’t move as it
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should through either the ear canal, the eardrum, or the three
bones in your middle ear the malleus (or hammer), the incus
(or anvil), and the stapes.
It can be caused by ear wax, a punctured ear drum, fluid in
the ear, or infection.
The result is that people feel that their ears are plugged.
This can be treated by surgery.
It is temporary most of the time.
About 10% of the 28,000,000 Americans who have hearing
loss have conductive hearing loss.
 The second type of hearing loss is sensorineural.
 Sensorineural hearing loss is by far the most common
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type.
It affects 90% of people with hearing loss.
This happens when damage occurs to the cochlea.
Sensorineural hearing loss can be a byproduct of aging,
infections, head trauma, exposure to loud noises, or
fluid build up.
This is a type of hearing loss that hearing aids can help.
I interviewed my friend Freya (age 10) who has hearing
loss and has to wear a hearing aid.
 Q: When did you get your 1st hearing aid?
 A: When I was 3 months old.
 Q: Did you like your hearing aid at first?
 A: No. I squirmed and tried to take them off.
 Q: Are there different types of hearing aids that your
parent could chose for you?
 A: Yes, there are a couple other types.
 Q: What do you like about hearing aids?
 A: I like that I can turn them off when I’m fed up with
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people talking to me.
Q: Is there anything you don’t like about hearing aids?
A: If I get an ear infection it hurts to wear it and gives
me a headache.
Q: Can you change the loudness?
A: Yes
Q: Can you change the pitch?
A: No.
 Q: Can you get them wet?
 A: With these new models, I can only get them wet for
half an hour.
 Q: What type of hearing loss do you have?
 A: I don’t know.*
*I think she has sensorineural hearing loss because my
book said that hearing aids can help people with that
kind of hearing loss.
100
90
80
70
60
50
Conductive
40
Sensorineural
30
20
10
0
Conductive
Sensorineural
 I learned that the four main parts of the hearing aid
are:
1.
2.
3.
4.
Microphone
Amplifier
Receiver/Speaker
Battery
 I also figured out that sensoreneural hearing loss is the
most common.
 Discovery Health “How The Hearing Aid Works”,
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http//www.
http://health.howstuffworks.com/medicine/moderntechnology/hearing-aid.htm
Physics of Sound, Delta Education
World Book Encyclopedia, Book H, Volume 9
The Sense of Hearing, Elaine Landau
The New Book of Popular Science
Freya Brandvik (my friend with a hearing aid)