Leila Hatch uses a variety of scientific tools to assist in her studies. One of her tools is a device called a hydrophone. Like a microphone, this research tool detects sound energy. The hydrophone, however, is designed for underwater use.

Below the sea surface, the hydrophone picks up sound waves that travel through the water. Although audible sounds are detected, the hydrophone also captures sounds outside the range of human hearing. By analyzing all of these frequencies, Leila learns more about how human generated sounds have an impact on the ecosystem.

In this activity, you will adapt a standard microphone for use as a hydrophone. Then, you will use this tool to explore the transfer and masking of underwater sounds. From what you experience, you will understand how sounds associated with large ships affect marine animals.