How Can We Hear So Many Different Sounds From Across The Room? (v1.0)
This middle school unit on sound starts off with students exploring a perplexing phenomenon where sounds and voices are heard coming from a paper cup and needle as a plastic disc (a record) is spun underneath it. This phenomenon fuels a series of questions and ideas for investigations to pursue about how sound is produced, how it travels, and how it is detected and encoded.
What STUDENTS INVESTIGATE
Students investigate dozens of phenomena over the unit, to help them uncover important pieces of the puzzle. Each piece of the puzzle they figure out helps them incrementally develop a model to explain their anchoring phenomena and answer their original questions. Here are just a few of these investigations...
We really wanted to inspect the record more closely. We use a magnifying glass, and some really interesting patterns on the surface of the record. We want a closer view. Looking at the surface of the record again through a powerful microscope reveals some really important clues about how different sounds might be produced and how all this information might be encoded.
Maybe some objects like the table or the floor don't vibrate when we hit them or walk on them. Or maybe these objects are vibrating just a little bit (at a scale that is too fast or too small for us to see). We come up with lots of ways to detect and inspect such motion, by slowing it down or scaling it up.
Graphing the motion of a vibrating object provide us clues about what might causing a sound to be louder vs. softer. There are so many interesting features in these graphs to compare, such as the repeating pattern it makes, the distance it travels, how long it takes for this pattern to repeat.
There are lots of instruments, like guitars, pianos, harps, xylophones, that produce different notes when we play them. A music box is another thing that does this. When we inspect the structure of all these devices more closely, we uncover a relationship between the length of an object and the pitch of the sound it produces when struck or plucked.
What students figure out
By the end of the unit, students develop powerful ideas about the nature of matter, energy, and waves to account for a variety of phenomena. These ideas include...
- All solid objects can be bent and will spring back, up to a point; this causes them to vibrate for a bit after being struck or plucked.
- Vibrating matter can produce sound; the volume and pitch of the sound that is produced is related to the amplitude and frequency of vibrations of the sound source.
- Collisions between the particles that make up matter can transfer energy through that material; sound is a pressure wave traveling through that material.
- Sound can make matter vibrate; different structures in our ear vibrate in response to different sounds and transmit signals to our brain through nerve cells
- The patterns of these vibrations can be encoded in either a digital or analog form; digitized signals are a more reliable way to encode and transmit information.
- Sound can be tracked as energy flows through a designed or natural system.
- When a wave meets a surface between two different materials or conditions, part of the wave is reflected at that surface and another part continues on.
Brian Aycock currently serves as the Third Grade Curriculum Coordinator for West Aurora SD 129. He is also the Elementary Director for the Illinois Science Teachers' Association. He is passionate about science education, and specializes in three-dimensional curriculum development and implementation. He resides in Downers Grove, IL with his wife Samantha, and his two children Brooklyn and Donovan.
Lisa Brody is a PAEMST Finalist and Illinois Science Teacher Association recipient and a middle school science teacher. Lisa holds a Bachelor's degree in Education from Indiana University and a Master's degree in Curriculum and Instruction from National-Louis University in Illinois. She has collaborated with leading science education researchers and has provided IQWST (Investigating and Questioning Our World through Science and Technology) workshops to teachers and administrators. Lisa focuses on what is best for her students and how they can propel their own thinking.
Malika Jones is a certified Teacher Leader in Science in the state of Illinois. She holds many degrees, among which are a B.S. in Biology, as well as a M.S. in Curriculum and Instruction. She has taught for over 10 years. In 2014, she was awarded the Teacher of the Year for Beach Park School District. She currently teaches 8th grade biology, trains teachers to use Next Generation Science methods and creates science and math curriculum.
Tara A. W. McGill is a Curriculum Development Specialist at Northwestern University. Prior to her current position, she taught ninth-grade biology in Chicago Public Schools and developed curriculum materials with Ag in Progress Partnership, NFP. She researched honey bee biology and behavior in the Entomology Department at the University of Illinois-Urbana/Champaign (UIUC). While at UIUC, she also performed informal science outreach and collaborated on several science education projects. McGill is also a facilitator and member of the design team for the Next Generation Science Exemplar System for Professional Development (NGSX), a web-based professional development system designed to help educators grow in their understanding of three-dimensional learning.
Michael Novak is a 2014 Golden Apple Fellow and National Board Certified teacher and a middle school science and social science teacher at Park View School. He has authored instructional units and computational models for the Center for Connected Learning at NU and has worked with partnerships in multiple states to develop NGSS-designed storyline based curriculum materials. Novak is also a facilitator and member of the design team for the Next Generation Science Exemplar System for Professional Development (NGSX), a web-based professional development system designed to help educators grow in their understanding of three-dimensional learning.
Keetra Tipton is an Illinois Science Teacher Association Outstanding Teacher of Science award recipient, and currently teaches middle school science. She holds a Bachelor’s degree in Zoology from the University of Wisconsin - Madison and a Master’s degree in Secondary Education from DePaul University. Keetra was a national field trial participant piloting science materials that were developed to help students engage in three-dimensional learning. She has collaborated with leading science education researchers and has provided IQWST (Investigating and Questioning Our World through Science and Technology) workshops to teachers and administrators. Keetra wholeheartedly believes that all students are able to learn to ask questions and design investigations to answer their own questions about the world. Her passion is coaching them through this process.