In this activity (11th activity on the page), learners use pennies to test their hearing acuity. Learners collect pennies, drop them one at a time on a hard surface and listen to the sounds they make. They may observe that newer pennies have a duller sound than older pennies that seem to "ring." Learners collect data, compare and can share their findings with the author of this activity. This activity page includes a link to background information about the ear and hearing.