Mind Control Helmet: A Fun Demonstration about Sound and Electromagnetism

Loudspeakers are devices that create sound, controlling the interaction between a permanent magnet and an electromagnet induced by a varying electric current in a coil. The physics behind loudspeakers makes them popular educational resources to discuss the principles of electromagnetism and the generation of sound waves. This same idea also applies to electric motors and generators. In this work, we combine electric motors and loudspeakers to build a set of headphones, which are presented to preservice primary school teachers as a “mind control helmet,” to demonstrate the basic ideas of electromagnetism and sound physics, but also the nature of science.