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. 


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.