Eerie ‘woman’s voice’ recorded by NASA deep in ocean still a mystery 25 years later

A loud and eerie noise coming from deep in the ocean remains a mystery to scientists, years after it was first discovered.

The noise, which sounds like a 'woman's voice', was captured in the Pacific, but it's completely baffled researchers.

In 1999, the National Oceanic and Atmospheric Administration (NOAA) recorded the sound in the Pacific Ocean.

After trying their best to pinpoint the noise and where it was coming from, the NOAA managed to narrow it down to an area of the Pacific that lies between the Branfield Strait and Cape Adare.

It was detected over 3,000 miles away and lasted for approximately three minutes. Nicknamed 'Julia', the sound is undoubtedly creepy and sounds like a woman humming.

But 25 years on, and it's still not entirely clear where or what it's come from.

The noise was heard deep in the Pacific Ocean (Getty Stock Photo)

The locations of Branfield Strait and Cape Adare aren't exactly close, and have hundreds of kilometres between them.

Since there wasn't any definitive theories at the time, many people have come up with eerie conspiracy theories regarding the origin of the noise.

For example, some people claim it was some sort of alien ship travelling underwater.

A Reddit post claims that at around the same time the noise was heard, 'pictures from NASA's Apollo 33A5 shows a large shadow swaying through the southwest section of Cape Cadre at the same time as the recorded sound'.

If you want to hear it for yourself, then you can listen to it here:

People are sceptical of the alien claims, however, with one writing: "Not really... if it's true, than this creature never bothered to attack us, or even cause trouble by travelling near one of our boats. Basically, nothing changes wether this is true or not. Sailing the ocean will be like it is right now."

While another said: "Actually there are several other cases of loud unidentified noises like this, and every single one has some lunatic conspiracy theory tied to it. It's the Internet, after all."

The NOAA has given their own suggestion that the noise might have been the result of an adrift iceberg.

They explained: "This sound was recorded on March 1, 1999 on the eastern equatorial Pacific autonomous hydrophone array.

"The most likely source of the sound formerly known as 'Julia' is a large iceberg that has run aground off Antarctica.

"Due to the uncertainty of the arrival azimuth, the point of origin could be between Bransfield Straits and Cape Adare with an origin time of 1999 JD60 21:05GMT."