Sound travels very differently in water because it is a denser, and therefore more elastic medium than air. This is why humans, whose ears are not adapted to hearing underwater, we cannot distinguish where a sound is coming from while submerged. Our marine mammal cousins have adapted to communicate on different sound frequencies. This ability – called echolocation – is essential to communication in whales and dolphins.
As humans are born, we open our eyes and see what is familiar. Eventually before we understand what is being said around us, we understand recognition in faces, rooms, shapes, etc. For dolphin this form of familiarity comes from sound.
Monkeys use one call specifically for one task, whereas dolphin can adapt and change the call for the command. This communication is so advanced that when different pairs (male dolphins tend to travel in couples), each dolphin will initially have their own call, but as they connect with another dolphin their calls become more similar until they are the same.
Humpback whales also have distinctive communication patterns that adapt and change. Like dolphin, these whales will change their songs over time as they mingle. The liquid environment allows for low frequency sounds to move globally. This means a whale can communicate to a whale half way across the globe and the acoustic transit time would only be 3.5 hours.
What is just amazing is that this is culture. An underwater symphony; it’s music. As the environment changes marine mammals reply. They sing to identify themselves, to warn of danger, they create common languages that are understood across the board.
It truly is a miracle, and this is why awareness on all fronts is important. We are only beginning to understand the complexity of the ocean and our impact on the environment. Right now, ships are the biggest source of human noise. Huge cargo ships can be so disorienting to whales that they will collide (generally fatal for the whale). Considering humans only figured out how to make transatlantic phone calls in the ‘20s, we have a lot to learn from the ocean (especially those that came out and went back in).
To learn more watch this TED video.