How do whales communicate and how do researchers learn about underwater vocalizations? Objective *How do scientists record and analyze underwater sounds? *What can scientists learn about whales by listening to their sounds in the sea? *How can this information help scientists in their efforts to protect whales and other marine animals? Background Our "Underwater Acoustics" curricula unit is divided into three lesson plans, each taking one class session to complete. They are part of our "Middle School Scientists" series that explore the fascinating research and resources of Glacier Bay National Duration: 60 Minutes.