Sound travels through the air in all directions, but it also bounces and reflects when it hits hard materials, such as walls. Inside the mausoleum there is nothing to muffle the air vibration, so sound bounces from the walls and creates reverberation.
After an introductory lesson demonstrating how sound travels in a circular pattern away from a sound source, the clip extends learning to highlight the fact that sound travels through some materials better than others. Ask the pupils to carry out a series of experiments to investigate this concept - tapping spoons under water, placing your ear on a wooden surface to listen to a ticking clock, using a string telephone. In each case, highlight the fact that sound travels by vibrations and the vibrations travel better through some materials than others. Before watching the clip, ask the children to think of any situations where sound doesn't appear to travel through a material (this will introduce the idea of insulators but may introduce the concept of echoes). The clip addresses the latter concept very clearly. Pupils could be challenged to suggest which type of materials allow reverberation and which do not.