Dolphins and toothed whales navigate and find food by producing high frequency, pulse *clicks", which bounce back off solid objects. They communicate with each other using a variety of other sounds - groans, moans and wwhistles. Baleen whales, like humpbacks, produce low frequency songs that travel for miles underwater. These sounds are produced by the respiratory system, especially the nasal cavity, rather than vocal cords.
Underwater sonar used by many ships and submarines can interfere with the echolocation and communication channels of Cetaceans, making it difficult to find mates and locate feeding grounds.