How Can We Hear So Many Different Sounds From Across The Room? (v1.0) 



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In this unit, students start by observing a perplexing phenomena.   When a sewing needle taped to a cone, is dragged over the surface of a plastic disc spun under it, voices and musical notes are heard coming from it.  This leads students to start noticing and wondering about other sound related phenomena, which in turn leads to wealth of new questions about…

  • What causes different sounds?
  • What is traveling from a sound source to my ear?
  • Why does the same thing sound different for people in different places


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...

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.