Killer whales, also known as orcas, are not only the largest members of the dolphin family but are also renowned as powerful apex predators in the marine world. However, did you know they might also have the ability to speak?

These fascinating creatures, equipped with the largest brains of any marine mammal, have evolved to swim up to 40 miles a day and can even hunt on land. According to National Geographic, their intelligence and adaptability are unparalleled in the aquatic world.

What may come as a surprise, though, is that orcas can apparently mimic basic human words such as 'hello' and 'bye bye.' This unexpected skill has been documented and is now drawing a mix of amazement and unease.

Amazingly, this phenomenon has been captured in a recording, which you can listen to below. Be warned, though—the sound is undeniably eerie and might send a chill down your spine.

The recordings were part of a 2018 study published in the journal Proceedings of the Royal Society B: Biological Sciences. This study brought together experts from Germany, Spain, the UK, and Chile to investigate the ability of orcas to mimic human language.

Josep Call, a professor at the University of St Andrews and co-author of the study, explained that the research team wanted to determine just how flexible orcas could be when it came to replicating sounds they weren’t accustomed to.

"We thought what would be really convincing is to present them with something that is not in their repertoire - and in this case 'hello' [is] not what a killer whale would say," Call told The Guardian.

To conduct the study, the researchers trained a 14-year-old orca named Wikie. She was first asked to replicate three sounds commonly made by her three-year-old calf, followed by five unfamiliar orca sounds. Finally, Wikie was exposed to six human sounds, including 'hello,' 'Amy,' 'ah ha,' 'one, two,' and 'bye bye.'

Wikie the whale succeeded in mimicking a number of human soundsAbramson et. al/CBS News

After analyzing Wikie's responses, the team found that she was able to imitate the sounds with surprising accuracy. In fact, she nailed two human utterances on her very first try, leaving researchers both impressed and intrigued.

Recordings of Wikie's attempts reveal a range of results. While some of the sounds she produced were surprisingly accurate, others sounded more like something out of a horror movie, drawing comparisons to goblins or other spooky creatures.

Listeners shared their reactions, with one describing the sound as: "The hello sounded demonic."

Another listener, adding a humorous spin, remarked: "OK, that second hello was a little demonic. Was that really an orca, or the Devil speaking through a ghost box LOL The funniest and scariest thing EVER! That's my day, can't stop laughing my head off lol."

Despite the unsettling nature of some of the recordings, many were left in awe of the orca’s ability. One person captured this sentiment perfectly: "This makes me tear up, the fact that we live in a such a beautiful world filled with wonderful creatures,"

Wikie the whale has impressed people with her soundsAbramson et al/CBS News

Although Wikie was only able to correctly replicate one human word—'hello'—more than half the time during subsequent trials, the findings marked a groundbreaking discovery. It was the first clear evidence that orcas might learn new sounds through vocal imitation.

"This is something that could be the basis of the dialects we observe in the wild - it is plausible," Call explained, shedding light on the significance of the study’s results.

What makes Wikie’s performance even more extraordinary is the vast difference between her vocal anatomy and that of humans, showing just how adaptable these animals can be.

Call expanded on this, saying: "Even though the morphology [of orcas] is so different, they can still produce a sound that comes close to what another species, in this case us, can produce."

However, he added an important caveat: "We have no evidence that they understand what their 'hello' stands for."

While the study with Wikie provides an intriguing starting point, Call emphasized that more research is needed. Future trials with wild orcas could offer additional insights into how these incredible creatures learn and replicate sounds.