What You Need:
- 2 empty containers with lids (soft plastic or metal recommended)
- Roughly 20-30 large wooden beads, plastic magnetic marbles or pennies
- 2 blindfolds
- 4 participants
- Duct tape
- Large space (e.g. exhibit floor, conference room, lobby, outdoors)
To Do and Observe:
Put about 10-15 marbles in each container and seal with duct tape. Give the containers a hard shake up and down to get a loud sound. Designate 2 of the participants as whales and the other two as their partner guides. Explain the instructions and roles of the participants: Each whale will be blindfolded and assigned a partner guide who will gently hold onto their arm underneath one of their elbows. The guides will lead the whales around the room until they are far apart. Important: Once the whales begin to communicate, the guides can no longer lead the whales. They must only protect the blindfolded participant from bumping into obstacles or people. One whale will use the shaker to send a sound. The other must receive the sound, then answer or “echo” with their shaker. Whales repeat this back and forth until they find each other. Once whales have found each other, the participants switch roles.
What's Going On:
Echolocation is how whales use sounds to locate objects (such as prey) and to orient themselves in their vast three-dimensional ocean realm. Water is an excellent sound transmitter and whales have capitalized on this characteristic of water to make up for reduced vision in the often dark and cloudy water of the sea. When sound is reflected after it strikes an object, it creates an echo. So, whales emit short sounds (called clicks) and locate objects by listening for the reflected echo. The animal can tell how far away the object is by measuring the time it takes for the echo to return to them.
As the children get more comfortable with this activity you can make containers with different materials to create different sounds. As one child is blindfolded, shake the container that you want them to reach. As they walk around (guided by their partner) you can have other children shake the other containers one at a time until the blindfolded person finds their match. This allows the person to recognize that there are different sounds and focus in on the one that they are listening for.