Whale Sounds and Songs 
 
All marine mammal species use sound to communicate. Sound is used during social interactions, to find food, navigate, avoid predators and monitor their surrounding environment.  Increasing manmade ocean noise is drowning out whale signals and placing them in grave danger.
 
Noises in the Dark

Sunlight travels only a short distance in seawater, so that even in daylight, deepwater remains dark.  Given the scarcity of light in the underwater environment, marine mammals rely on sounds (not vision) as their primary sense for navigation, communication with other animals, and interaction with the surrounding environment.
 
Sound travels efficiently in water (5 times faster and 60 times further than in air).

 A Wide Range of Whale Sounds and Frequencies

Marine mammals make a wide variety of sounds, differing in type, frequency and strength. The sound frequencies used by cetaceans vary from below what humans can hear, such as the 10Hz calls of blue whales, to frequencies far higher than those we can hear, such as the 120kHz clicks of the harbour porpoise.

From the rapid clicks and whistles of dolphins, to the low-frequency booms of blue and fin whales, these extraordinary vocalizations and sensory abilities allow marine mammals to take advantage of the ocean's physics.

Toothed whales such as sperm whales, killer whales, beaked whales and dolphins use echolocation to find food and obtain information about their surroundings. By emitting sounds that create echoes from nearby objects, toothed whales can recognize the shape, size, direction, distance, and density of surrounding objects.

Acoustic communication is also important to the social habits of marine mammals that spend time on land.  Female seals, for example, use vocalizations to find their pups on crowded breeding beaches and the roars, grunts and other sounds of male seals are important ways to communicate threats or territorial displays.

Going the Distance

The loudest sounds come from the great whales, such as the humpback, blue and fin whale.

Male humpback whales sing long and complex songs during the breeding season that can be heard from several miles away. Each song contains a wide range of sounds, can last up to 20 minutes, and may be repeated for hours on end.   The song is different each year, but all males in the population sing the same song to attract females.

The deep booms of fin and blue whales can be detected over distances of up to 2,000 miles. Scientists are still debating whether these incredible sounds are being used as a form of communication or possibly also some form of long-range sonar to detect underwater features.