whale vocalization

whale vocalization, process used by whales that produces any of several vocal sounds that assist in communication and the collection of information about their environment. Whales vocalize primarily to navigate, share information with one another, find food, locate other whales, and compete (for food, mates, or territory), and some researchers speculate that whales may use vocal sounds to overwhelm senses of their prey. Whale vocalization includes clicks, whistles, grunts, moans, squeaks, and pulsed calls. Researchers note that the meaning of some of the sounds change according to their pitch, rate, and structure.

All whales possess a larynx; however, of the two living suborders, only baleen whales (suborder Mysticeti) use the larynx as a vocalization organ. Toothed whales (suborder Odontoceti), in contrast, communicate by passing air through their nasal passages.

Toothed whales

The utterances of toothed whales—which include pilot, sperm, beaked, and killer whales, along with dolphins and porpoises—are usually high-pitched clicking sounds that fall into the range of between 5 and 150 kilohertz (kHz). To produce the pulses of sound used in echolocation, a toothed whale blows air through a vibrating tissue, called the phonic lips, in its nasal passages, which lie beneath its blowhole. The clicking sound travels through a fatty organ, called the melon, on the whale’s forehead and then travels out through the water. Once the sound waves strike an object, they bounce back through the water to the whale, and vibrational energy is conveyed to the whale’s inner ear via a structure called the acoustic window in the lower jaw.

In at least one species, such communication may be more than simply rudimentary. The clicking patterns that occur in sperm whales (Physeter macrocephalus), according to a 2024 study, could be evidence of a phonetic alphabet. Researchers discovered that sperm whales create codas—that is, strings of between three and 40 clicks—when they communicate with one another. Of the 156 distinct codas in the study, some appeared be used to identify individual vocalizing whales, whereas the meanings of other codas were unknown. During the study, researchers also observed a phenomenon they called rubato, in which sperm whales changed the tempo of a coda when repeating it. In response, other nearby whales also changed their coda tempos. Members of the species were also shown to, on occasion, add an extra click, called ornamentation, to the end of a coda (see also coda, in music).

Baleen whales

To the human ear, the sounds produced by baleen whales—which include rorquals and humpbacks, right, and gray whales—are beautiful, eerie songs that contain repeating patterns. They are usually low-frequency signals that occur between 0 and 5 kHz, although higher-pitched sounds are also used in their songs, and the range of pitches varies between species. To sing, a baleen whale blows air through a U-shaped ridge of tissue at the top of its larynx. This structure uses recycled air, instead of inhaled air, and thus gives baleen whales the ability to sing underwater without drowning. The songs of baleen whales have been shown to change over time, as pods (that is, traveling groups of related individuals) listen to and incorporate the patterns of one another. Within some species, different pods use different versions, or dialects, of sounds, possibly to identify members of their own pod. Their songs can carry long distances through the ocean, some as far as thousands of kilometers. The sounds produced by shipping vessels occur in the same narrow band of frequencies, which makes it difficult for baleen whales to communicate, especially over long distances.

During the 1960s underwater microphones, which originally had been used to detect the movement of submarines, recorded the songs of humpback whales. Some of these songs were released on Songs of the Humpback Whale (1970), a record album made by American biologist Roger Payne, American zoologist Katharine Boynton Payne, and U.S. Navy engineer Frank Watlington. By the early 1970s several whale species, many of which had been hunted for their oil for centuries, including humpback whales, were listed as endangered species. The album became the best-selling nature recording in history, and its notoriety helped to raise public consciousness about the plight of whales. Excerpts from the album were included on the gold-plated copper phonograph record sent into space on the Voyager 1 and Voyager 2 spacecraft in 1977, and the album itself was inducted into the National Recording Registry of the U.S. Library of Congress in 2010.