Sound is caused by a vibrating air column within the instrument’s body

1. Brass Instruments • Sound is caused by a vibrating air column within the instrument’s body • Vibrating lips allow sound waves to pass through the mouthpiece into the instrument • Ex: trumpet, French horn, tuba, cornet, baritone • Changing Pitch (Frequency) in Brass • Blow harder to make the air resonate at higher natural frequencies • Pressing valves that change the length of the tube • Changing Volume (Amplitude) • Blowing into mouthpiece with more/less force

2. Woodwind Instruments • Sound caused by a vibrating reed and vibrating air column • Mouthpieces contain 1 or 2 reeds that vibrate the air column when the musician blows into the mouthpiece • Ex: oboe, clarinet, saxophone, flute, piccolo (both involve the player blowing across a narrow opening to make the air column vibrate) • Changing Pitch (Frequency) in Woodwinds • Musician changes the length of the resonating column of air • Close and open finger holes along the length of instrument • Changing Volume (Amplitude) • Blowing harder/softer into the mouthpiece

3. Percussion Instruments • Sound is caused by striking the instrument, or vibrating the membrane • Drums and Other Percussion Instruments • Tightening the drumhead increases the natural frequency of the drum resulting in higher pitch sounds • Larger the size of the drum body, the lower the pitch. • Xylophones have wooden or metal bars of different lengths • The longer the bar, the lower the sound • The shorter the bar, the higher the sound • Changing Volume (Amplitude) • Striking the top surface causes it to vibrate; the vibrating drumhead is attached to a chamber that resonates and amplifies the sound

4. Strings Instruments • Sound is caused by strings, like vocal chords, which vibrate back and forth as air is forced past them, which creates a series of compressions and rarefactions in the air • Changing Pitch in Strings • Longer string length = Longer wavelength = Lower frequency = Lower pitch (low) • Shorter string length = Shorter wavelength = Higher frequency = Higher pitch (high) • Tight string = more tension = high frequency = high pitch • Thicker string = Low frequency = Low pitch • Changing Volume (Amplitude) • Sound produced by a vibrating string is soft, to amplify the sound, instruments have a hollow chamber, or a resonator • Resonator contains air and absorbs energy from the vibrating string and vibrates at its natural frequencies

5. String Length and Thickness

6. Objective 10/30/2012 Page 48 SW connect the behavior of sound waves to sound properties through notes and video clips. Jumpstart After the musical instrument lab the past two days, what can you conclude about pitch (frequency) and volume (amplitude) of instruments overall? Outro How was ‘the boy without eyes’ able to “see”? Explain.

7. Behavior of Sound Waves NOTEBOOK PAGE 49 PACKET PAGE 6

8. Reflection of Sound Waves (pg 6) • Echo- A reflected sound wave • Smoothhardsurfaces reflect best • Rough soft surfaces reflect poorly • Energy not reflected is absorbed or transmitted through the material

9. Echolocation • Echo- a reflected sound wave • Echolocation- using the reflection of sound waves (echo) to navigate, locate prey, and to determine the direction and distance of objects • Used by bats, dolphins, whales • Can humans use echolocation? • Use ears to interpret echoes (to estimate size/shape of room) • Ben Underwood!

10. Bat Echolocation

11. Ultrasound • High frequency sound waves (+ 20,000 Hz) • Animals • Bats & Moths • Ultrasound emitted by bats causes flying moths to make evasive maneuvers, because bats eat moths. • Dogs • Dog whistle? 16 kHz - 22 kHz • Dolphins • Hear ultrasound, have their own natural sonar system • Medicine • Alternative to surgery – focus sound waves on kidney or gall stones, break them up, safely pass through the body • Make images on the inside of the body • Examine developing fetus • Examine internal organs

12. Infrasound • Low frequency sound waves (less than 20 Hz) • Communicate over varying distances of up to many miles • Waves are diffracted around objects because of the long wavelength • Animals • Elephants • allow them to communicate over long distances • Whales • Hippos, rhinos, giraffes • Natural Earth Processes • Ocean waves • Avalanches, earthquakes, volcanoes • Meteors • Man-made Processes • Explosions (chemical, nuclear)

13. Ben Underwood Infrasound and Echolocation Finding Nemo "Dory! This is not whale. You're speaking like, upset stomach." 1m 44s What type of sound waves do whales use? Infrasound! Boy who “sees” without eyes 10m 15s Ben died on January 19, 2009 at the age of 16, from the same cancer that took his sight…

14. "The Mosquito" • When: Launched late in 2008 • What: A device which emits a very high frequency (17khz - KiloHertz) tone • Why: Annoy teenagers in the hopes that the teenagers will not loiter around storefronts • New Development: Students learned that they could use the same frequency as their cell phone ringtone • They could receive text messages and phone calls while in class! • Age 24+ usually lose the ability to hear high frequency sounds • Age 50+ might not hear anything higher than a 10khz tone. 

15. S o n a r • Page 6 • SOund Navigation And Ranging; a system of detecting reflected sound waves • Navigation- finding your way around • Ranging- finding the distance between objects • Used by submarines and ships • Ship sends out a sound wave • Sound wave hits the bottom • Sound wave bounces back • SONAR measures the time it takes to detect the reflectedsound waves (long time = far away) • Map undersea features, detect submarines, schools of fish and other objects • Submarines and Sonar Video • Start 20s; 2m15 s

16. The Doppler Effect • Change in wave frequency caused by a moving sound wave source • moving toward you  high pitch • Waves pile up = shorter wavelength = higher pitch • moving away from you  low pitch • Waves spread out = longer wavelength = lower pitch • Doppler Effect Video 1m09s

17. Objective 10/30/2012 Page 48 SW connect the behavior of sound waves to sound properties through notes and video clips. Jumpstart After the musical instrument lab the past two days, what can you conclude about pitch (frequency) and volume (amplitude) of instruments overall? Outro How was ‘the boy without eyes’ able to “see”? Explain.

18. Objective 11/01/2012 Page 50 SW familiarize the properties of sound with the speed of sound and relate it to temperature through graphing and video. Jumpstart Explain the difference between Ultrasound and Infrasound. Outro What exactly is a “Sonic Boom”?

19. Speed of Sound NOTEBOOK PAGE 51 PACKET PAGE 15

20. Speed of Sound- Page 15 • The speed of sound depends on the properties of the medium through which it is traveling

21. Speed of Sound- Review- Page 15 • Elasticity - the ability of a material to bounce back after being disturbed • More elastic = faster • Solid = most elastic • Liquid = not very elastic • Gas = inelastic • Density– the amount of matter in a given volume • More density = particles closer = faster • Temperature- a measure of the average kinetic energy of the molecules • Higher temperature = faster • Lower temperature = slower

22. Breaking the Sound Barrier • When an object passes through the air, it creates a series of pressure waves in front of it and behind it. • These waves travel at the speed of sound, • As the speed of the object increases, the waves are forced together, or compressed, because they cannot "get out of the way" of each other. • When the object reaches the speed of sound, the waves merge into a single shock wave. • This critical speed is known as Mach 1—761 mph!! • Speed of Sound Video 2m10s • Beyond the Speed of Sound Video 38 s Rapid condensation of water vapor due to a sonic shock produced at sub-sonic speed creates a vapor cone

23. Moving Faster than Sound • Oct. 14, 1947, Chuck Yeager became the first person to fly faster than the speed of sound. He flew at a high altitude in order to do this. Why? • At higher altitudes the air is colder, so sound travels more slowly. • So, to break the sound barrier at a high altitude, he did not have to fly as fast as he would have at a lower altitude. • LOWER TEMPERATURE = • SLOWER TRANSFER OF ENERGY = • LOWER SPEED OF SOUND • Oct. 15, 1997, Andy Green became the first person to drive a land vehicle faster than the speed of sound. Why did he choose to drive in the desert? • Cooler at night and in the morning • Flat • Large open spaces

24. DID YOU KNOW…“Cracking” the whip • The cracking sound a bullwhip makes when properly wielded is, in fact, a small sonic boom? • The end of the whip, known as the "popper", moves faster than the speed of sound, thus resulting in the sonic boom. • The whip is the first human invention to break the sound barrier.

25. Page 15- Graph the Data • Show how the speed of sound through air changes with temperature. Show temperature from -20°C to 30°C on the horizontal axis. Plot speed from 318 m/s to 348 m/s on the vertical axis. • Should you choose a line graph or a bar graph for this data?

26. Page 15- Graph the Data • Show how the speed of sound through air changes with temperature. Show temperature from -20°C to 30°C on the horizontal axis. Plot speed from 318 m/s to 348 m/s on the vertical axis. • Should you choose a line graph or a bar graph for this data?

27. Objective 11/01/2012 Page 50 SW familiarize the properties of sound with the speed of sound and relate it to temperature through graphing and video. Jumpstart Explain the difference between Ultrasound and Infrasound. Outro What exactly is a “Sonic Boom”?

28. Outro Answer • When an object passes through the air it creates a series of pressure waves in front of it and behind it. • These waves travel at the speed of sound, and as the speed of the object increases, the waves are forced together, or compressed, because they cannot get out of the way of each other….eventually merging into a single shock wave at the speed of sound.

29. Mythbusters Video- page 8“Breaking Glass” 16m28s • In this video, Adam and Jaime try to test the myth that a singer can break glass using only their voice.