Weddell seals in Antarctica have been found to produce ultrasonic vocalizations reaching up to 50 kHz, a discovery made possible by the sensitive equipment of the McMurdo Oceanographic Observatory in McMurdo Sound. Researchers identified nine recurrent call types with ultrasonic frequencies, prompting speculation that these seals might be using echolocation or a distinct communication channel, as these sounds dissipate rapidly underwater. The unique electronic and synth-like nature of these calls, with 17% of recorded vocalizations being ultrasonic, challenges previous assumptions about pinniped vocal range and suggests a potentially overlooked aspect of marine mammal communication, though concrete evidence for echolocation remains elusive.