Sperm whales change ‘vowel’ sounds when boats are nearby, scientists discover

Scientists working off the Caribbean island of Dominica say sperm whales appear to alter their clicking patterns when boats are close by, adding a new piece to the puzzle of how the animals communicate and react to human activity at sea.

According to a monitored public feed from The Guardian World, researchers involved in Project Ceti — the Cetacean Translation Initiative, a nonprofit effort focused on understanding sperm whale communication — spent four years listening to the calls of 15 sperm whales near Dominica. During that work, they detected a distinct pattern of clicks that showed up when marine traffic was nearby.

The researchers say the pattern is clear enough that it can now be used to anticipate the presence of ships. The finding suggests that sperm whales may not simply be making random noises, but adjusting their vocal behavior in response to disturbances in their environment. The feed summary describes the sounds as “vowel” changes, indicating that the whales’ audible clicks vary in a recognizable way when boats approach.

Sperm whales are among the most vocal marine mammals, and their clicks are thought to play a central role in communication. The new observation may help scientists better understand how the animals respond to shipping noise, a persistent feature of busy ocean routes that can overlap with marine life behavior.

Project Ceti has been studying sperm whale calls in an effort to decode aspects of their communication. The group’s long-term recordings off Dominica gave researchers enough data to compare whale sounds with the presence of vessels nearby. From that comparison, they identified a signal that stands out from the whales’ usual clicking.

The report highlights how advances in passive acoustic monitoring are allowing scientists to observe changes in animal behavior without direct interference. In this case, the work was based on listening to whales in their natural setting and matching those recordings with nearby marine traffic.

The researchers’ ability to predict boats from whale clicks also points to a possible practical use for the findings. Beyond the question of whale communication itself, the pattern could offer another way to detect the effect of shipping on marine mammals.

This article is based on a monitored public feed and attributed to The Guardian World. Source: The Guardian World - https://www.theguardian.com/environment/2026/jul/22/sperm-whales-dominica-clicks-vowels-language-changes-shipping-noise-project-ceti