Testing the upper limits of dolphin range accuracy

Bottlenose dolphins are known for their intelligence. Using echolocation, they can distinguish between microsecond delays in the return call to track their prey.

Researchers can test a dolphin’s range accuracy — how precisely it can estimate the distance of an object using echolocation — with a jitter-delay task. This utilizes a phantom echo generator (PEG) to manipulate the time it takes an echo to return to the dolphin.

Pardini et al. explored how the accuracy of this technique can be affected by the number of jitters.

“The echo delay gives the dolphin information about how far away an object is, so by jittering the echo delay, quickly moving the object back and forth, we can determine the limits of echo delay or range accuracy,” said author Madilyn Pardini.

The dolphin Comet, who had participated in jitter-delay experiments before, was trained to make clicking sounds and then produce a noise only if the returned sound was jittered.

The researchers observed that Comet’s accuracy in detecting jitter delay increased with the number of jittering echoes, but only up to a certain point.

This shows dolphins can combine information across multiple echoes, consistent with the previously studied multiple looks decision model, and confirmed a probable upper limit of information processing.

“We plan to continue to use the PEG system to manipulate different parts of the returning echoes to fine-tune our understanding of which properties of the echoes are most important to the dolphins,” Pardini said. “The motivation behind this research is to gain a deeper understanding of how dolphin echolocation functions, with the potential to use these findings to build better man-made sonar systems.”

Source: “Effect of the number of jittering echoes on jittered delay accuracy in a bottlenose dolphin,” by Madilyn R. Pardini, Austin O’Kelley, James J. Finneran, Katie A. Christman, Jason Mulsow, and Dorian S. Houser, Journal of the Acoustical Society of America (2026). The article can be accessed at https://doi.org/10.1121/10.0046470 .