Transcript Sound Waves - cloudfront.net

Sound Waves
If a tree falls in the forest
and no one is around to
hear it does it make a
sound?
Check THIS out
What causes sound?
vibrations in the air from
voices or objects create
sound
Sound Waves are produced when
vibrations from an object (like a
speaker) collide with molecules in the
air and pass energy to them.
Sound waves are compressional
waves
Sound waves can travel
through other mediums,
like water.
They cannot travel
through empty space.
If a person screams in
empty space, do they make
a sound?
Speed of Sound
Depends on.........
1. Medium (gas, liquid, types of solids)
2. Temperature - sound travels faster through warm air
Is hearing and
listening the same
thing?
How we hear sounds:
1. Compressional waves enter ear
2. Eardrum transfers waves to 3 tiny bones - all serve to
AMPLIFY the sound
3. Waves are converted to nerve impulses by the cochlea
4. Brain decodes and interprets that information
Anatomy Attack!
Can you name the parts of the ear (# 4, 6, 7, 9 )?
What is INTENSITY?
= amount of energy that flows through a certain area, we
perceive it as loudness
Intensity decreases with distance
Decibel
Scale (dB) measures sound
intensity
Sounds over 120
dB may cause
pain and hearing
damage
Pitch is related to frequency of sound waves
do, re , mi, fa, so, la, ti, do
Compare a high pitch to a low pitch:
http://www.flashmusicgames.com/
A healthy human ear can hear at frequencies
from 20 Hz to 20,000 Hz
As you grow older, hairs in your cochlea become damaged, which
results in hearing loss.
The mosquito ring tone capitalizes on this by providing teenagers a
ring that adults cannot hear.
Test it at http://www.jimmyr.com/blog/hearingloss.html
Analyzing Charts
What is the frequency
(HZ) and Decibel (dB)
level of a crying
baby? _________
A vacuum? _______
A motorcycle? ______
A telephone? ______
A water faucet? _____
A dog bark? _______
Most people can't hear sound above 20,000 Hz
- these are called ultrasonic waves
Subsonic waves have frequencies below 20 Hz
You might not hear them, but you can feel them "rumble"
How do dog whistles work?
Dogs can hear up to 35,000
Hz. This is beyond the range of
human hearing
Test it at http://www.jimmyr.com/blog/hearingloss.html
1.
2.
3.
4.
5.
Which 2 animals have the largest hearing range? ______________
Which animal can hear the highest frequency sounds? ______
What range of hearing does a fish have? __________
Which animal has the smallest range of hearing? _______
The range of a rodent's hearing is similar to that of a __________
ULTRASONIC WAVES - frequencies above 20,000 Hz
SUBSONIC WAVES - frequencies below 20 Hz
Ultrasonic Liposuction?
New fad or does it work?
Advertisement ....
Thanks to ultrasonic waves (approximately
40 kHz) excess fat pockets are removed
without any bleeding or pain. The ultrasonic
waves cause the release of water from the
fatty storage areas.......
Discuss.....
Sonic boom
created as this
jet breaks the
sound barrier.
A sonic boom is the sound associated with the shock
waves created by an object traveling through the air
faster than the speed of sound.
Sonic booms generate enormous amounts of sound
energy, sounding much like an explosion.
Youtube Video on Sonic Boom
Mythbusters
Sonic
Boom ~10
minutes
1.
2.
3.
4.
Light travels [ faster / slower ] than sound.
Supersonic travel breaks the [ light / sound ] barrier.
The shockwave begins at the [ wing / nose ] of the jet.
Humans can produce a sonic boom using a [ whip / horn ].
What is the Doppler
Effect
Moving objects that have
sound change pitch
depending on their direction
and speed - this is called the
Doppler Effect
Doppler Effect Video
1. The Doppler Effect occurs when a source of sound or light
[ moves / changes frequency ].
2. The high pitch sound of a car horn turns into a
[ low / higher ] pitch when the car passes.
3. The [ blue / red ] shift is evidence the universe is expanding.
What is Music?
Sounds produced in a deliberate
pattern
Instruments produce sounds of
different frequencies.
Itunes top 10?
Guess what songs are on the list this week?
*Check Your Guesses Here
Frequencies of guitar strings
depend on thickness, length
and how tightly it's stretched.
Sound is amplified by
resonance, instruments have
a component that make the
sound louder
Types of Instruments
1. Strings
violin, cello, guitar
Strings produce notes, hollow
chamber (resonater) amplifies
sound
Stretching the strings changes the
pitch - something you can try with
a rubber band
2. Brass and Woodwinds
What is this
instrument?
Examples: flute, trumpets, clarinets
A woodwind instrument is a musical
instrument where player blows air against
a sharp edge or through a reed, causing
the air within its resonator to vibrate.
Most are made of wood, but can also be
made of brass or other metals.
saxophone
3. Percussion
shaken or struck to produce air
vibrations
Examples:
drums, triangles
See Drum Kit wiki for
samples of drum beats.
Drum Line Video
What is this instrument? xylophone
How Well Do You Know Instruments?
TRUMPET
BONGOS
TUBA
FLUTE
What is Acoustics ?
the study of sound
The design of concert halls can
change the way music sounds
due to reflection and absorption of
sound waves
A scientist who works in the field
of acoustics is an acoustician
while someone working in the
field of acoustics technology may
be called an acoustical engineer.
What is Audiology?
= the study of hearing
An audiologist is a health-care professional specializing in
diagnosing and treating and monitoring disorders of the auditory
a system portions of the ear. These disorders may cause
hearing and balance problems/
Audiologists can dispense
hearing aids and recommend
and cochlear implants.
What is
Echolocation?
animals use sound to identify
and track prey and navigate
environment
Bats and Dolphins use
echolocation
What does "NAVIGATE" mean?
What is Ultrasound Imaging?
Ultrasound waves are directed at a
body, the waves reflect off organs
and produce signals that are sent to
a monitor. The monitor produces an
image
The image produced is called a
SONOGRAM
What is an Ultrasound Technician ?
also called Diagnostic
Medical Sonographer
work in laboratories or
hospitals where they
capture the images of
the inside of a human
body
Many schools offer 1-2 year programs to earn your degree.
Average Salary is $60,000 per year, that's about $30.00 per
hour. See Ultrasound Technician for more info
Using cornstarch and the right frequency of sound - you can
make a...... CORN STARCH MONSTER
QUIZ TIME!
Name of Quiz: Sound
1. Sound travels faster in [ warm / cold ] air.
2. The bones of the ear serve to ______________ the
sound.
3. Sound moves through air by colliding with
[ molecules / energy ].
4. Sound moving through air is a
[ transverse / compressional ] wave.
5. Sound intensity is measured in ____________
6. Sounds waves with frequencies below 20 Hz are
called [ ultrasonic / subsonic ]
7. Name an organism that uses echolocation:
___________
8. The image produced by an ultrasound is called a
__________________________
9. What do you call a person who diagnoses and treats
hearing problems? ____________________
10. Give one example of a percussion instrument.
Go back to Chapter 9 Waves- 1
ppt