Discovery+Center


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DISCOVERY CENTRE ACTIVITIES:__ 1. Magical Whisper Tube 2. Name That Sound 3. Musical Instruments (Drum, Acoustic guitar, Xylophone, Tuning Fork) 4. The Human Ear 5. What's The Sign? 6. Can ou Hear Me Now? 7. Slinky Activity 8. Water and Pitch 9. Sound Transmission 10. What's That Sound? 11. The Science of Sound 12. Hearing **

__**1. Whisper Tube**__ • The sound waves bounce off the sides of the tube.  • They reinforce each other and amplify the sound that reaches your ear. 1. One person whispers in one end of the tube. 2. Other student hold the other end of the tube to ear and listens. 3. Switch roles!
 * Activity**
 * Use a much softer voice than your normal speaking voice.

Activity** We hear many different sounds everyday. There are 20 different sounds on the CD. They are all sounds we have heard before, whether it be at home, at school, or outside in our own backyard. Put on the headphones, press play, and try to figure out what each sound could be!
 * __2. Name That Sound__

__**3. How Does An Acoustic Guitar Work?**__ The most important piece of the body is the **soundboard ** . This is the wooden front of the guitar's body and its job is to make the guitar's sound loud enough for us to hear. In the soundboard is a large hole called the **sound hole ** . Attached to the soundboard is a piece called the **bridge ** , which acts as the anchor for one end of the six strings. The bridge has a thin, hard piece embedded in it called the **saddle ** , which is the part that the strings rest against. When the strings vibrate, the vibrations travel through the saddle to the bridge to the soundboard. The entire soundboard is now **vibrating ** . The body of the guitar forms a hollow soundbox that **amplifies **  the vibrations of the soundboard. 1. Try strumming the guitar. Watch the strings vibrate! 2. <span style="font-family: Baskerville,helvetica,sans-serif; font-size: 18px;"><span style="font-family: Arial,Helvetica,sans-serif; font-size: 70%; letter-spacing: 0px;">Touch the **<span style="font-family: Arial,Helvetica,sans-serif; font-size: 70%;">tuning fork ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 70%; letter-spacing: 0px;"> to the bridge of a guitar. You will see that the vibrations of the soundboard are what produce the sound in an acoustic guitar! **__How does a drum work?__** A drum is a musical instrument in the percussion family. It is technically classified as a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over one or both ends of the drum. Using parts of a player's body or a drumstick, hit the drumhead which will then vibrate to produce sound. It is usual for a drum to have some sort of hole in to let air move through the drum when it is struck. If the hole is covered, the drum is very quiet. When the vibration passes through the air hole a louder and longer the notes of the drum. The sound of a drum depends on several variables including shell, size, thickness of shell, type of drumhead, position of the drum, location, how it is struck, etc. Drums are among the world's oldest and most ubiquitous musical instruments, and the basic design has been virtually unchanged for hundreds of years. Hit the drumhead in the center using the drumstick. Describe the sound you hear. Then, using the same instrument hit near the edge of the drumhead this time. Describe the sound that you hear. Is it different then the first sound? If it is, is it higher or lower? Why do you think this happened? Now, repeat the activity using your hand. Is there a difference between the sound that the drumstick made and the sounds your hand makes? <span style="font-family: Arial,sans-serif; font-size: 10pt;">__**The Tuning Fork**__ A tuning fork is a small metal instrument with a handle and two prongs or tines. Tuning forks, made of steel, aluminum, or magnesium-alloy will vibrate at a set frequency to produce a musical tone when struck.The pitch that a particular tuning fork generates depends on the length of the two prongs. Its main use is as a standard of pitch to tune other musical instruments. **<span style="font-family: Arial,sans-serif; font-size: 10pt;">What’s Happening? **<span style="font-family: Arial,sans-serif; font-size: 10pt;">As a tuning fork vibrates, it causes molecules in the air to move. The molecules bump into other molecules nearby, causing them to move. This process continues from molecule to molecule. The result is a series of compressions (molecules crowded together) and rarefactions (molecules spread apart) that make up sound waves. <span style="color: black; font-family: Arial,sans-serif; font-size: 10pt;">The xylophone (Greek for "wooden sound") is a musical instrument in the percussion family. This instrument consists of wooden bars of various lengths that are tuned to a specific pitch and struck by a mallet to create a sound. What’s Happening: ** <span style="font-family: Arial,sans-serif; font-size: 10pt;">As pitch is created by the frequency of vibrations per time, the more vibrations created, the higher the pitch will be, and the fewer vibrations created, the lower the pitch will be. When the wooden bars of the xylophone are struck with the mallet they vibrate, pushing and pulling the air particles around them. The shorter the bar is on the xylophone, the higher the pitch, and the longer the bar the lower the pitch.
 * Activity**
 * Activity**
 * <span style="font-family: Arial,sans-serif; font-size: 10pt;">Activity: **<span style="font-family: Arial,sans-serif; font-size: 10pt;"> Grasp firmly on the end of the tuning fork, keeping your wrist flexible and fingers and arms relaxed. Bend your elbow when holding it. Pick a hard surface you feel comfortable striking with metal (such as a desktop). Hold the tuning fork on its side so you're striking only one of the prongs. The "U" shape causes both sides to vibrate and produces a smooth sound wave. Strike the tuning fork prong about one-third of the way from the top (this is important to get the best sound). Set the vibrating tuning fork carefully on a hard surface like a desk or a chair seat. This acts as a sounding board and amplifies the pitch.
 * <span style="font-family: Arial,sans-serif; font-size: 10pt; line-height: 26px;">__The Xylophone__ **
 * <span style="font-family: Arial,sans-serif; font-size: 10pt; line-height: 26px;">Activity: **<span style="font-family: Arial,sans-serif; font-size: 10pt;">Play the Xylophone! Try striking a short bar and then a longer bar. What do you notice? Can you find a relation between the length of a bar and the pitch it creates? Why do you think this is? **<span style="font-family: Arial,sans-serif; font-size: 10pt; line-height: 26px;">

<span style="font-family: Arial,Helvetica,sans-serif;">Of course you know that if you spin around in circles you will get dizzy. But do you know why? When you spin, fluid in the semicircular canals of your ear moves around. This stimulates the hair cells. When you stop spinning, the fluid still moves a bit. Because the fluid is still activating hair cells, your brain stills gets a message that you are moving and you feel dizzy. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%; letter-spacing: 0px;">** Activity ** Read the following paragraph silently, or with a partner. The human ear has three main sections, which consist of the outer ear, the middle ear, and the inner ear. Sound waves enter your outer ear and travel through your ear canal to the middle ear. The ear canal channels the waves to your eardrum, a thin, sensitive membrane stretched tightly over the entrance to your middle ear. The waves cause your eardrum to vibrate. It passes these vibrations on to the hammer, one of three tiny bones in your ear. The hammer vibrating causes the anvil, the small bone touching the hammer, to vibrate. The anvil passes these vibrations to the stirrup, another small bone which touches the anvil. From the stirrup, the vibrations pass into the inner ear. The stirrup touches a liquid filled sack and the vibrations travel into the cochlea, which is shaped like a shell. Inside the cochlea, there are hundreds of special cells attached to nerve fibers, which can transmit information to the brain. The brain processes the information from the ear and lets us distinguish between different types of sounds. •Fill out the fill-in-the-blank paragraph.
 * __4. The Human Ear__**

For centuries, people who were hard of hearing or deaf have relied on communicating with other through a series of visual cues. Sign language is a visual language that incorporates gestures, facial expressions, head movements, body language and even the space around the speaker. Hand signs are the foundation of the language. Actions are often expressed through hand signals that mimic action being communicated- for example if you wish to sign the concept “eat”, you would bring your fingers and thumb of your dominant hand together as if holding food and then move your hand towards your mouth. The alphabet is an important series of signs. Some hand signs for letters resemble the written form of the respective letter. When you use the hand signs for letters to spell out a word, you are **finger spelling**. Finger spelling is useful to convey names or to ask someone the sign for a particular concept. <span style="font-family: Verdana,helvetica,sans-serif; font-size: 12px; line-height: normal;">**Activity** While completing this activity you are not allowed to use your voice. Using the sign language chart, try finger spelling the alphabet. Once you are familiar with the individual letters, try finger spelling your name! If you’re looking to be challenged try finger spelling your first, middle and last name. •** What was the biggest challenge you encountered when you couldn’t use your voice to communicate? • What alternative way(s) did you use to communicate? • Did you find it easy to communicate? If so, why? • Could your partner understand what you were trying to say?
 * __5. What’s the Sign?__**
 * [An alternative way to communicate]**
 * What did you think?
 * Record your thoughts in your science journal.

Have you ever wondered what it’s like to completely loose your ability to hear or loose your hearing to some degree? Well now is your opportunity. Grab a pair of earplugs (provided) and put them in your ears. Answer the following questions in your science journal: Next, explain how to play your favorite sport or activity with a partner.
 * __6. Can you hear me, now?__**
 * Activity**
 * Can you hear? If yes, what?
 * Are sounds as clear as they used to be, or is it difficult to hear sounds clearly?
 * Was it easy to understand what they were saying?
 * Did your partner have to repeat themselves?
 * Could you hear everything they were saying to you?

**<span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;"> __7. Sound Waves: Slinky Activity__ ** Activity ** <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;">Stretch the Slinky out on the floor or a table with a partner holding the other end. One of you represents the sound source and the other represents the sound receiver (the ear). The person representing the sound source gives the slinky a slight push. Now do the same thing but with a firmer push. <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;">What is moving from one end of the Slinky to the other? Do the coils of the Slinky travel away from one person and towards the other? When the intensity of the push changes is there a difference in the wave created? <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;">A slinky can model sound waves traveling through solids, liquids or gases. Each coil represents a molecule of the material. With a push, the coils compress against each other. The compression travels to the other end of the Slinky as a wave. Sound travels through solids, liquids and gases as a compression wave. Energy is transmitted through the coils and travels from source to receiver. When an object begins to vibrate, the molecules next to it are compressed or pushed together. This compresses molecules further out. When the object moves back, a space in the air is created next to the object. The first molecules of air expand to fill this space, causing molecules further out to expand too. This compression and expansion of the air molecules is called a sound wave.
 * <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;">
 * <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;">Questions to Consider: **
 * <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt;">How the Slinky Models a Sound Wave: **

Activity: **<span style="font-family: Arial,sans-serif; font-size: 10pt; line-height: 26px;">Using the spoon provided, tap each water glass gently on its side. What do you notice about the pitch of the sound created? Do all of the glasses create the same pitch? Why do you think this is? <span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 26px;"><span style="color: black; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 150%; mso-ansi-language: EN-CA;">The less water there is in the glass, the higher the pitch will be, just as the more water there is in the glass, the lower the pitch will be. This is due to the vibrations of the water. <span style="font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 150%; mso-ansi-language: EN-CA;">The more water that is in the glass, the more vibrating material there is and the lower the pitch when struck with a spoon.
 * <span style="font-family: Arial,sans-serif; font-size: 10pt; line-height: 26px;">__8. Water & Pitch__
 * Questions to Consider:**
 * <span style="color: black; font-family: Arial,sans-serif; font-size: 10pt; line-height: 26px;">What’s Happening: **

__**9. Sound Transmission**__
 * Activity:** <span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">Position the steel tube over the watch on the table. Can you hear it ticking? Now, remove the steel tube and lower your ear at the same distance from the watch as you were with the steel tube. Can you hear the ticking? If so, is the ticking louder or softer than when you listened to it through the steel tube? Next, take the plastic bag filled with water and place it against your ear. Have someone hold the watch against the bag of water. Can you hear the ticking? Did the water transmit the sound?


 * <span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">What’s Happening: **<span style="font-family: 'Arial','sans-serif'; font-size: 10pt;"> Sound waves can travel through any substance, including gases (such as air), liquids (such as water), and solids (such as steel). Sound waves disperse less energy when travelling through liquids and solids, compared with air. This allows them to travel more quickly and to retain intensity. Did you know that sound cannot exist if it doesn't have something to travel through? For example, sound cannot travel through outer space because it is a vacuum and contains nothing to carry sound.

__**10. What’s That Sound?**__ Questions to consider**:** * Respond to these reflection questions in your science journal.
 * Activity**
 * Using the audio recorder (provided), go around the classroom or entire school (but make sure you have permission before you leave) and record as many different sounds as you can find. Then, bring the recorder back to our classmates and play the sound(s) you have recorded. After they have listened to the sound(s) have them guess what the sound is and where you would find it. Write down your guesses and compare them to the actual answers after you’ve tried to identify all of the sounds. You can do this activity in pairs, as a group or as a class. **
 * Were there some sounds that were hard to identify? If so, why?
 * Were some sounds similar? If so, which ones?
 * What part of the sound helped you identify it’s source [for example, pitch, length, etc.]?

__**11. The Science of Sound**__

<span style="font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 115%;">1. Watch the video “The Science of Sound”. 2. Answer the 8 questions on the sheet provided. Try to answer them as you watch the video (press pause if you need to). 3. Don’t forget to put your name!
 * <span style="font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 115%;">Activity **

<span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">Sounds enter your ears through the pinna, which is the part of the ear that you can see. The sounds travel along the ear canal to the eardrum. When sounds hit the eardrum they make it vibrate. **<span style="font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 115%;"> Activity: How does the eardrum work? ** <span style="font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: 115%;">Here is a model eardrum. The plastic wrap on the bowl represents the eardrum. Now m <span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">ake some noise! Hold the cookie sheet close to the plastic wrap. Hit the cookie sheet with the spoon to create a "big bang" noise and watch the rice grains jump. Now you know how sound causes your eardrum to vibrate, sending messages to your brain about the sounds you're hearing!
 * <span style="font-family: Arial,sans-serif; font-size: 10pt;">__12. Hearing__ **