This short clip features a simple demonstration of how we humans hear sounds in stereo. It is ideal for use as a lesson starter in KS3/4 science. A physicist has invented a device called a 'Confusaphone'. When worn, the Confusaphone mixes up the sound going into your left and right ears. He gets a volunteer to put on the Confusaphone, then plays a sound, and asks the volunteer to point to where the sound is coming from. The volunteer can't differentiate between sounds that come from left and right. However, he can differentiate between sounds made in front of him and behind. The questions posed for students to answer are: How is sound getting to the ears? Why are two ears better than one? See the accompanying teachers' notes for a full explanation of the science underpinning the demonstration, plus suggested extension activities.

Video Series: Lesson Starters
Release Date 2009