Station 1: Homemade Telephone Could a whisper be heard across the room through the air? Could a whisper be heard across the room through the cups? What did whispering do to the bottom of the cup? Talk into one end while pinching the string. Describe what happens. Why? Talk into the phone while the string is slack. What happens? Why?

Station 1: Homemade Telephone Sound needs a medium to travel through. Would you hear sound in space?

Station 2: The Decibel Scale What is the loudest sound that you recorded on the decibel meter? What happened to the sound’s intensity when the meter was farther away?

Station 2: The Decibel Scale Look at the decibel scale on page 288 of your textbook. What do you think the loudness of the classroom is right now?

Station 3: Finding Your Way in the Dark Were you able to detect exactly where your partner was standing when you weren’t using the tube? Were you able to detect exactly where your partner was standing when using the tube? Which ear did the sound hit first when you were using the tube? What’s the difference?

Station 3: Finding Your Way in the Dark Sound moves about 340 m/s (about 760 mi/hr), although it depends on the pressure and temperature of the air. Lightning causes thunder; they occur at the same time. You hear a delay because sound travels much slower than light.

Station 4: Tuning the Water Record what you see and hear for the small and large tuning fork. What happens when it faces other directions? Do you think that sound travels through water? What causes the waves? SOUND IS CAUSED BY ____________! VIBRATIONS

Station 5: The Singing Glass Record your observations on what you hear both times. What is your finger actually doing when it rubs the glass rim? What can be done to create a higher sound? Lower sound? SOUND IS CAUSED BY ____________! VIBRATIONS

Station 6: Reed Straws Record your observations for what you hear and feel for the three different reed instruments. What is causing the sounds to be different? How is the length of the straw related to the pitch of the sound? SOUND IS CAUSED BY ____________! VIBRATIONS

Station 7: The Swinging Tube Record your observations describing the sound that you heard as you swung the tube. Define frequency, hertz, and pitch. In a couple sentences, describe how those three words relate to the swinging tube observations that you made.

Station 8: Palm Pipes Design an experiment to create a sound using the pipes. Describe what you tried and explain what happened. Try hitting the pipes on the palm of your hand to create a sound if you haven’t already. What happens to the sound as the length shortens. What is creating the sound?

Station 8: Palm Pipes Happy Birthday MelodyCCDCFECCDCGF HarmonyAABb A MelodyCCCAFEDBb AFGF HarmonyFCBbCA

Station 8: Palm Pipes Twinkle Twinkle Little Star MelodyFFCCDDCBb AAGGF HarmonyCCAABb AGGFFEEC MelodyCCBb AAGCC AAG HarmonyAAGGFFCAAGGFFC MelodyFFCCDDCBb AAGGF HarmonyCCAABb AGGFFEEC

Station 9: Sound Frequency What is the lowest frequency that you can hear? What is the highest frequency that you can hear? Do you think that all people can hear the same frequencies?

Station 10: Slinky Sound Wave How does the longitudinal wave (like sound waves) compare to the transverse waves? How you can you make different longitudinal waves with the slinky? Experiment and explain how the waves you created are different. Does the relationship between wavelength and frequency hold true for longitudinal waves? How do you know? Draw one of the longitudinal waves you created with the slinky.

Station 10: Slinky Sound Wave

Air is made up of molecules constantly in motion, bumping off each other.

Station 10: Slinky Sound Wave High pressure means lots of molecules in a certain volume (very dense), low pressure means few molecules in the same volume.

Station 10: Slinky Sound Wave A sound wave looks something like this. Sound is a longitudinal wave where there is high pressure and low pressure.

Station 10: Slinky Sound Wave

Example of sound being longitudinal waves of air pressure: Flame Tube

Station 11: Oscilloscopes and Sound Waves What did a wave look like for loud sounds? What about for soft sounds? What did the wave look like for high sounds? What about low sounds?

Station 11: Oscilloscopes and Sound Waves Identify each wave as high or low and loud or soft.

Station 11: Oscilloscopes and Sound Waves Draw a wave the represents noise and one that represents sound. Sound Waves are not usually perfect waves like you think of them.

Station 12: Complex Sounds Describe the sound of the four frequencies 264 Hz, 330 Hz, 396 Hz, and 528 Hz when they were played together. Describe the sound of the four frequencies 264 Hz, 317 Hz, 396 Hz, and 528 Hz when they were played together. How do the two sounds compare?

Station 13: Beats What do you hear when there are two different frequencies at the same time? What do you hear when there are two of the same frequencies at the same time? The sound pattern you hear is called a beat. What happens to the frequency of the beat when the two sounds have close frequencies? What about when the two frequencies get farther apart?

Station 13: Beats Read about beats on page 301. What causes beats? Think about your wave interference assignment.

Station 14: Perfect Circles Picture 1 describes how sound normally travels. It travels away from a central point in all directions.

Station 14: Perfect Circles Picture 2 describes the Doppler Effect. Doppler Effect If there is a higher frequency, the pitch sounds ______. If there is a lower frequency, the pitch sounds ______. higher lower

Station 14: Perfect Circles Picture 3 describes a sonic boom. When something travels faster than the speed of sound, the waves get built up in a shock wave. We hear a SONIC BOOM!

Station 14: Perfect Circles Examples of sonic booms: Really fast airplanes Lightning Bullets They say that you will not hear the bullet that kills you.

Conclusion In a few sentences, summarize your ideas of how sound travels and the factors that influence pitch and amplitude.