Geophysicists use sound waves to build a picture of the magma and rock beneath this active volcano, most of which is underwater. It's like CT scanning the Earth.
Data from hydrophones in the Indian ocean has raised new questions about what happened to MH370.
Noisy waters may be making it harder for southern resident killer whales to communicate with each other and find their food.
The noise from motor boats, sonar and other industrial activity interferes with the underwater chatter of fishes.
Loud noise from underwater seismic surveys can drive penguins from their normal foraging grounds.
A new method of analysing underwater sound waves has led to the creation of a faster, more informative tsunami early warning system.