How Can Pitch Change? Grade Level: 3 I. SECTION ONE: Identifying standards and objectives A. PA Academic Standards for Science and Technology: 3.1.4.C. Illustrate patterns that regularly occur and reoccur in nature. Use knowledge of natural patterns to predict next occurrences. 3.2.4.A. Identify and use the nature of scientific and technological knowledge. 3.4.4.C. Observe and describe different types of force and motion. Identify characteristics of sound (pitch, loudness, echoes) 3.7.4.B. Use appropriate instruments to study materials. Explain appropriate instrument selection for specific tasks. National Standards: Content Standard A: Abilities necessary to do scientific inquiry Content Standard B: Properties of objects and materials Content Standard F: Types of resources Content Standard G: Science as a human endeavor B. Enduring Understandings: A. Pitch changes based on the frequency in which vibrations occur. Therefore, if a person were to hit a glass of water harder, it would create faster vibrations. When talking about pitch in a person s voice, this can be altered by a persons own self-control. When a person is scared and screams, generally the pitch of their voice becomes higher; in contrast, when a person is talking normally, that is the natural pitch of their voice and is usually much lower than a persons scream. Sound must have the following criteria to exist: 1. Vibrations 2. Contact with the air 3. The listener must be within a certain distance to hear the noise 4. The air contact between source and listener must be constant B. Even without water in bottles, the pitch level is affected by the different types of bottles you may be experimenting with. For example, when a container is wider and not very thick, it will have a lower pitch. When a container is skinnier and longer, it will have a higher pitch. The same goes for the amount of water present in those containers.
The more water, the lower the pitch, the less water, the higher the pitch. C. Essential Questions: A. What makes pitch change? B. In what ways is pitch affected by water levels in a glass bottle? D. Performance standards: (more standards in procedures) -To meet the standards, 1. Students will know a. Why water affects pitch b. How the words pitch, sound, amplitude and frequency differ c. That vibrations come through our throat to make sound d. If food coloring also alters pitch level e. How to work in pairs to complete a task f. To follow instructions given by the teacher and work in an efficient manner 2. Students will be able to a. Alter water level to change pitch b. Determine whether water in a smaller bottle will have the same pitch as a different, larger bottle with the same amount of water c. Explain how to achieve a low pitch level d. Compare their voice to a bottle and determine which bottle pitch matches their voice the closest e. Compare and contrast how pitch and sound differ II. SECTION TWO: Identifying assessment 1. Pre-Assessment: Checking for prior knowledge (Science Talk, KWL, pre-test) Intrigue with vibrations in neck while speaking Ask students to hum, speak, and sing while touching their throats. Have students notice that when they hum a song their pitch goes up and down or hum a song for the students and ask if they can hear the pitch going higher and lower and you go. 2. Formative: Periodically, check for understanding by Explain how water slows vibrations Ask students if you d need more or less water in a glass bottle to create lower pitch? Mix up jars and label highest to lowest pitch in groups of 3 or 4. 3. Summative: End of the lesson check for understanding, be sure to include a RUBRIC/ Task Sheet where necessary Explain why or why not food coloring affects pitch level
Create jars with various pitches and have students explain to one another how the sounds change. Be sure to have students use appropriate vocabulary. 4. Adaptations for Special Needs Students For those students who don t understand: bring a xylophone into the class and show students different sounds and how they range from low to high pitches. For an extension: find other things that make noises and have students compare one to another. Recognize which has a higher or lower pitch. III. SECTION THREE: Identifying lesson activities 1. Materials 13 single-serving glass juice bottles (8 for the initial experiment, 2 for the food coloring section, and 3 for the other liquids section) Pitcher of water Milk Rubbing alcohol Seltzer water Food coloring Whistle Unsharpened pencils Computer Website that has games for students to play that have various pitches: http://www.smartboardmusic.org/freegames.html Various sized glass bottles (not single-serving glass bottles) 2. Procedures Engage: 1, 3, 4, 5. i. First, ask students how sounds are made. Ask them to think about it to themselves for a few minutes and when they reach an answer to give a thumbs up. Have a class discussion about the various answers. ii. Next, ask students why does water move when trying to create sound. Demonstrate this by blowing a whistle right next to water, this will show waves in the water. Another example you could use is to talk about trying to talk to someone underwater in a swimming pool. Bubbles are visible (which is movement of water) and you can hear what they are saying up to a certain distance. iii. Discuss what the terms pitch, vibration, sound, amplitude and frequency mean. Pitch: the degree of height or depth of a tone or of song, depending upon the relative rapidity of the vibrations by which it is produced.
Vibration: the rapid movement of particles of a mass of air to create waves on a still surface. Sound: the sensation produced by stimulation of the ears by vibrations transmitted through the air or other medium. Amplitude: the size of the vibrations, which determines how loud the sounds are. Frequency: the speed of the vibrations, which determines the pitch of the sound. Explore 2, 5 i. Have students gather around the area where you will be performing the experiment. Make sure all students are able to see, as well as close enough to hear what you are saying and what pitches come from the glasses. ii. Arrange the 8 single-serving glass juice bottles side by side. Label bottles with letters A H. iii. Fill the first bottle with the most water and decrease the amount of water added to each bottle as you put water in. The first glass bottle should have the most water, the last glass bottle should have the least amount of water, and the rest of the bottles in between those two should have varying decreasing amounts of water. iv. Tap each bottle with an unsharpened pencil. NOTE: wait until one bottle s pitch is finished before you start to tap the next bottle. You won t want to cause confusion about these pitches among the students. v. Ask students if each note is higher or lower in pitch. Explain: 1, 2, 4, 5 vi. Explain the vibrations for each bottle. When you tap the bottles lightly, there are slower vibrations, which causes quieter noises. When you tap the bottles with more force, there are larger vibrations, which cause louder noises. vii. Class discussion What made the pitch change? Guide students to talk about water level and how that affected pitch level. Then, ask students how do you know that it was the change in water level? viii. What would happen if we put this same amount of water (from any of the bottles A-H) in a glass bottle that is smaller? Will the pitch be the same? What if we put that same amount of water in a glass bottle that is larger? Then how will the pitch change? Also, look at different widths of glasses. Elaborate: 1, 2, 4, 5 Begin with the question what would happen if you changed the color of the water? Also, what would happen if you tried to make noises with different types of liquid in the bottles?
i. Fill two glass bottles (of the same size) with the same amount of water. ii. Add 5 drops of green food coloring to one bottle. iii. Add 5 drops of red food coloring to the other bottle. iv. Tap the green colored bottle with an unsharpened pencil and listen to its pitch. v. When that bottle is done quiet again, then tap the red colored bottle with an unsharpened pencil and listen to that bottles pitch. vi. Discuss whether you think the pitch is different between the two bottles. Lead students to questions about what would happen if there were a different liquid in the glass jar. vii. Now fill three other glasses (of the same size) with different liquids and tap them. Fill one bottle with milk, one with rubbing alcohol, and the other with seltzer water. Evaluate: 1, 2, 3, 4, 5 i. Class discussion has pitch changed based on color? How do you know? ii. Did using different liquids other than water affect the pitch? iii. Ask students to determine different ways they could alter the pitch of a certain object. What are other ways students want to try to alter this experiment to change pitches.