Download Outer Ear

Making Human Sounds
• When you speak or sing, you push air
from your lungs past your vocal
cords, which are two flaps of tissue
inside your throat. When you tighten
your vocal cords, you can make the
sound have a higher pitch. Do this lab
to explore how you change the shape
of your throat to vary the pitch of
sound.
Making Human Sounds
1. Hold your fingers against the front of
your throat and say Aaaah. Notice
the vibration against your fingers.
2. Now vary the pitch of this sound
from low to high and back again.
How do the vibrations in your throat
change? Record your observations
on page 110.
Making Human Sounds
3. Change the sound to an Ooooh.
What do you notice as you
listen? Record your
observations.
4. Think critically In your science
notebook on page 110 describe
how the shape of your throat
changed the pitch.
Sound
What do you hear?
• Did you hear something? Maybe the sound
you heard was as quiet as your cat licking
her paws. Or maybe it was loud, like a
siren going by.
• Sounds are everywhere, and you have two
cool parts on your body that let you hear
them all: your ears!
• No matter where we go, sound waves are
all around us.
Sounds
Close your eyes and listen to these sounds.
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Sound
• Question: What is sound?
–A vibration that produces a
wave.
–http://teachertube.com229809
Sound
• A wave carries energy from one place to
another without transferring matter.
• An object that is vibrating in air, such as
your vocal cords or a ear bud speaker
produces a sound wave.
Sound
Sound
• Epiglottis: Flap of skin that covers the
larynx during swallowing, preventing food
from entering the trachea.
• Trachea: windpipe that carries oxygen to
the lungs and carbon dioxide out.
• Larynx: Upper part of the respiratory
system that holds the vocal cords.
• Vocal Cords: Vibrate during speech to
produce sounds.
• Fire Video
http://www.youtube.com/watch?v=93DFan
OXzL8
Sound
• The vibrating object causes air
molecules to move back and forth. As
these molecules collide with those
nearby, they cause other air
molecules to move back and forth. In
this way, energy is transferred from
one place to another. This is done
just as the slinky moves back and
forth.
Sound
• Question: Can you experience sound
waves by feeling vibrations?
– When the bass is turned up high.
Sound
• Question: Does sound travel faster in air
or through a solid material?
– Recall that as sound waves travel through a
material, the particles collide with each other.
• Question: Are particles of a material closer
together in a solid or a gas like air?
– In a solid particles are closer together than in
liquids or gases.
– Therefore speed of sound is fastest in solids.
Sound
• Sound waves are mechanical waves,
which means they need a medium to
travel through and they can’t travel
through a vacuum.
• It is the sound energy that travels through
a medium not the particles of the medium.
• The particles of the medium move back
and forth as the sound wave passes, but
then return to their original positions.
Sound
Sound
• What is SONAR?
• Sound Navigation And Ranging.
– Uses sound to detect objects under the
surface of the water. Videos: Submarines and Sonar 2, Dolphins Sonar
1:30
Sound
• Question: What is the difference between
loud sounds and quiet sounds?
• What is the difference between playing a
song at a high volume versus a low
volume?
– Loud sounds carry more energy than soft
sounds.
Sound
• Loudness is the human perception
of how much energy a sound wave
carries.
Sound
• Decibel Scale: Measure of the
energy carried by sound
waves.
Sound
• Dangerous levels of sound energy.
• You must learn to protect your hearing or you
may have hearing problems later in life.
• Have you ever had ringing in your ears?
Sound
• Pitch: How high or low a sound is.
Pitch corresponds to frequency. The
higher the pitch the higher the frequency.
• Question: Name a musical instrument with
a high pitch.
• Question: Name a musical instrument with
a low pitch.
Sound
• Pitch: Humans can detect frequencies
between about 20Hz and 20,000Hz.
• Dogs can detect up to 50,000Hz.
• Bats as high as 150,000Hz.
Sound
• Echo: A reflected sound wave
Sound
• Echolocation: Emitting high
pitched squeaks and listening for
echoes to determine location.
• Bats and dolphins use echolocation to
navigate.
•
Video: Echoes and
Echolocation 1:29
Sound
•
Sound waves can be used to treat certain
medical problems.
1.
Small incision is made in the eye, then an ultrasonic instrument
uses sound waves to break up the lens, and the particles are
removed.
Breaking up kidney stones.
2.
Video: Ultrasound 2:44
Music
• Music: A group of sounds
deliberately produced to make a
regular pattern.
• The difference between music and noise
can vary from person to person.
• Music is created by vibrations.
– You beat a drum, the head vibrates. You play
a guitar the string vibrates. You tap a bell, it
vibrates at a certain frequency.
Music
• Natural frequencies: Every object
will vibrate at a certain frequency.
Music
• Question: How can someone singing at a
loud high note cause glass to shatter?
– Sometimes sound waves can cause an object
to vibrate.
– Scientific American article.
– Video: Shattering Glass
• 5:18
Music
• Resonance: An object is made to vibrate
at its natural frequency by absorbing
energy from a sound wave.
– The vibrating tuning fork causes the table to
vibrate at the same frequency, or resonate.
The combined vibrations of the table and
tuning fork increase the
loudness of the sound
waves produced.
Music
• Question: Before a concert what do all the
musicians do?
– Tune their instruments by playing the same
note.
Music
• Most musical instruments produce
more than one frequency at which
they vibrate.
• Fundamental frequency: The
lowest frequency produced by a
vibrating object.
• Overtones: Higher frequencies
produced by a vibrating object.
Music
• Reverberation: Repeated echoes
of sound.
– In a empty gym the sound of your voice can
be reflected back and forth several times by
the floor, walls, and ceiling.
– Video: Reverberation 2:15
Comparing and Contrasting
Sounds Activity
• Strike a block of wood with a spoon and listen
carefully to the sound. Then press the block of
wood to your ear and strike it with the spoon
again. Listen carefully to the sound.
• Tie the middle of a length of string to a metal
spoon. Strike the spoon to hear it ring. Now
press the ends of the string against your ears
and repeat the experiment. What do you hear?
Record your observations.
Comparing and Contrasting
Sounds Activity
• Data and Observations: Sound
1.Wood:
2.Wood against ear:
3.Metal spoon:
4.String against ear:
Comparing and Contrasting
Sounds Activity
• Analysis:
1.Did you hear sounds transmitted through
wood and through string? Describe the
sounds.
2.Compare and Contrast the sounds in
wood and in air.
Ear
•
Definitions:
anvil - (also called the incus) a tiny bone that passes vibrations from the hammer to
the stirrup.
cochlea - a spiral-shaped, fluid-filled inner ear structure; it is lined with cilia (tiny
hairs) that move when vibrated and cause a nerve impulse to form.
eardrum - (also called the tympanic membrane) a thin membrane that vibrates when
sound waves reach it.
Eustachian tube - a tube that connects the middle ear to the back of the nose; it
equalizes the pressure between the middle ear and the air outside. When you "pop"
your ears as you change altitude (going up a mountain or in an airplane), you are
equalizing the air pressure in your middle ear.
hammer - (also called the malleus) a tiny bone that passes vibrations from the
eardrum to the anvil.
nerves - these carry electro-chemical signals from the inner ear (the cochlea) to the
brain.
outer ear canal - the tube through which sound travels to the eardrum.
pinna - (also called the auricle) the visible part of the outer ear. It collects sound and
directs it into the outer ear canal
semicircular canals - three loops of fluid-filled tubes that are attached to the
cochlea in the inner ear. They help us maintain our sense of balance.
stirrup - (also called the stapes) a tiny, U-shaped bone that passes vibrations from
the stirrup to the cochlea. This is the smallest bone in the human body (it is 0.25 to
0.33 cm long).
Ear
• Outer Ear: Collects sound waves
and directs them into the ear canal.
Ear
• Middle Ear: Sound waves vibrate the
eardrum, which is a membrane that
stretches across the ear canal. When the
eardrum vibrates, it transmits vibrations to three
small bones which amplify the sound
Ear
• One of the three small bones vibrates
another membrane leading into the inner
ear, which is filled with fluid. Vibrations in
the fluid are transmitted to hair-tipped
cells. These cells generate signals
containing information about sounds. The
nerve impulses from the cells then travel
to the brain.
•
Video: Ear 1
• Worksheet.
Cochlear Implants
• Brain Pop “Hearing”
• Little Girl Hearing for the First Time
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• Baby ZDD7Ohs5tAk