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Sound Waves What causes sound?

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Presentation on theme: "Sound Waves What causes sound?"— Presentation transcript:

1 Sound Waves What causes sound?
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

2 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

3 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?

4 Speed of Sound Depends on.........
1.  Medium (gas, liquid, types of solids) 2.  Temperature - sound travels faster through warm air

5 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

6 Anatomy Attack! Can you name the parts of the ear  (# 4, 6, 7, 9 )?

7 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

8 Pitch is related to frequency of sound waves
                   do, re , mi, fa, so, la, ti, do Compare a high pitch to a low pitch:                          

9 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   

10 On the ear, circle or shade the  COCHLEA.
Draw and arrow to the eardrum Place a check mark next to the nerves that connect to the brain.

11 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? _______

12 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 

13 1. Which 2 animals have the largest hearing range. ______________ 2
1.  Which 2 animals have the largest hearing range? ______________ 2.  Which animal can hear the highest frequency sounds? ______ 3.  What range of hearing does a fish have? __________ 4.  Which animal has the smallest range of hearing? _______ 5.  The range of a rodent's hearing is similar to that of a __________

14 Ultrasonic Liposuction? New fad or does it work?
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.....

15 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. 

16 Youtube Video on Sonic Boom
Mythbusters Sonic Boom  ~10 minutes 1.  Light travels  [ faster / slower ] than sound. 2.  Supersonic travel breaks the [ light / sound ] barrier. 3.  The shockwave begins at the [ wing / nose ] of the jet. 4.  Humans can produce a sonic boom using a [ whip / horn ].

17 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.

18 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

19 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

20 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

21 2.  Brass and Woodwinds          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.  What is this instrument? saxophone

22 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

23 How Well Do You Know Instruments?
TRUMPET BONGOS TUBA FLUTE

24 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.

25 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.

26 What is Echolocation? animals use sound to identify and track prey and navigate environment Bats and Dolphins use echolocation  What does "NAVIGATE" mean?

27 What is Ultrasound Imaging
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

28 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

29 Using cornstarch and the right frequency of sound - you can make a
Using cornstarch and the right frequency of sound - you can make a......  CORN STARCH MONSTER

30 QUIZ TIME! Name of Quiz:  Sound

31 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 ]

32 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.

33 Go back to Chapter 9 Waves- 1 ppt


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