Generally speaking, whales are believed to make noise to either navigate, communicate, locate food or find other whales.
All whales are very social creatures that travel in groups called “pods.” They use a variety of different noises to communicate and socialize with each other. The three main types of sounds made by whales can be specified as clicks, whistles, and pulsed calls.
In the animal kingdom these clicking sounds are believed to be used for navigation and identifying their physical surroundings. You may have already heard of bats using this exact same technique, known as echolocation or biological sonar, to fly in the dark and locate potential prey and predators. But they are not the only ones. Dolphins, toothed whales and some types of birds are also well known for using this extraordinary technique, as it allows them to move around in pitch darkness, while still being able to navigate, hunt, identify friends and enemies, and avoid obstacles.
This is how it works: When the soundwaves produced by one of these animals bounce off of an object, the echoes returning from all directions help the animal to form a 3-dimensional picture of its environment, helping them to identify the shape and distance of the object and thus allowing the animal to ‘see’ further than their eyes are able. Specifically for Dolphins and toothed Whales these sounds are produced by squeezing air through their nasal passages near the blowhole. These soundwaves then pass through the forehead, where a big blob of fat called the melon focuses them into a beam. If the echolocating call hits something, either an object or another animal, the reflected sound is picked up through the animal’s lower jaw and passed to its ears. Echolocating sounds can be really loud, hence the ears of dolphins and whales are shielded to protect them.
Experts also believe these special clicking sounds to play a role during social interactions, suggesting they may also have a communicative function.
Similar to the variety of languages and dialects of the human language, differing vocal “dialects” have been found to exist between different pods within the same whale population. This is most likely so that whales can differentiate between whales within their pods and strangers.
Did you know that some humans are also able to use echolocation? Some blind individuals have learned to use echolocation to sense details of the environment by making clicking sounds with their mouths. Studies have shown that this is possible with lots of training, even for people who are not sight impaired.
In addition to clicks, most toothed whales also produce whistle-type sounds. Humpback whales for example are famous for their singing abilities, as you probably remember Dory demonstrating in the iconic Finding Nemo scene. Interestingly only males sing, and their singing is heard most often but not exclusively during mating season. The singer is usually alone in a head-down, tail-up position, but occasionally another Humpback will join in. Humpback whales do not have vocal cords, so the way they produce sounds is by pushing air through tubes and chambers in their respiratory system. Using underwater microphones, whale researchers have recorded the sound of different species communicating underwater as a method of detecting, tracking, and identifying whales. One way to analyze these recorded signals is to digitize them using a computer and to display them as a spectrogram, which are visual representations of the spectrum of frequencies of a signal, in simpler terms a way to visualize sound like a picture. Hypotheses to why whales sing exist, but researchers do not know the absolute reason. The most common theory is not much different from the clicking explanation, as it is believed to serve as a way to communicate their location to other males, attract females, navigate, find food, and communicate with each other.