Distinct Echolocation and Communication Signals Across Odontocete Clades

Air-Driven Sound Production System Provides Physiological Basis

Tissue Vibration in Different Registers Produces Distinct Signals

Scientists have discovered that toothed whales, including dolphins and porpoises, use tissue vibration in different registers to produce distinct echolocation and communication signals. This finding, published in the journal Nature Communications, provides a physiological basis for the diverse vocalizations observed across all major odontocete clades.

Odontocetes are known for their complex echolocation abilities, using high-frequency sound waves to navigate and hunt in dark marine environments. The new study shows that these whales possess a unique sound production system based on air driven through nasal passages. This system allows them to produce sound vibrations in at least three registers: the vocal fry register, the modal register, and the falsetto register.

The researchers found that the different registers produce distinct echolocation and communication signals. The vocal fry register, for example, generates low-frequency sounds used for short-range communication, while the modal register produces mid-frequency sounds used for echolocation. The falsetto register, on the other hand, generates high-frequency sounds used for long-range communication.

This study provides new insights into the evolution and diversity of vocal communication in toothed whales. It also has implications for understanding the vocal repertoire of other marine mammals, such as seals and sea lions.