The sound device you made is the same design as a dynamic speaker found in almost all audio equipment made. It converts electrical energy into mechanical movement that produces sound. Let’s see how this works.   Take a look at this demonstration below:

When we allow electron flow through a coil it produces an electromagnetic field. This can oppose or attract a fixed magnet. This then is how electrical energy is converted to mechanical energy.  Now see how the manufactured speaker is designed:

There are good expanded descriptions on the web.  See (Links to an external site.) as an example.

Optional: If you want to make this demonstration for yourself, it is fun to see first hand. Take note in the videos above how the system operates and by using the materials below, make your own.

Materials Needed:

If you wish to make this demonstration you will need:

• Two water bottles

• Gravel or rocks

• Tape

• Cardboard strips (provided)

• 2 magnets  (provided)

• 2 corks  (provided)

• 2 blocks of wood  (provided)

• Double sided tape   (provided) or glue 

PLEASE RESPOND: With the speaker provided, try this experiment.  Feel the speaker cone as you strum the clip on the screen. Do you feel the mechanical motion of the speaker cone?

Move on to next assignment.