What is Apple up to at this secret facility?

BANGS, thumps and humming noises are heard under the cover of night at this mysterious Apple facility.

IT’S Apple’s very own Area 51.

Mysterious noises in the dead of night emanating from a secretive Apple facility have residents of a working-class suburb of California spooked and demanding answers.

They claim to have been harassed by heavy-handed security guards while walking their dogs near the complex, located in an industrial area just off a busy freeway, the San Jose Mercury News reports.

Apple, which has occupied the land since 2014, has refused to comment. But speaking to the local newspaper, residents complained of being disturbed by all kinds of bizarre sounds for the past few months.

Bangs, thumps, the beeping of trucks and something Jamie Rouleau, 58, described as sounding like someone “waving around” a large piece of sheet metal.

Strangest of all is a “whine or hum” that rises in pitch, like industrial machinery winding up, “loud enough to wake you”, Mr Rouleau told the paper.

Another local told CBS News: “At three in the morning, they have deliveries. It’s very dark, very secretive. We don’t know what’s going on, but almost every night there is noise that wakes the dogs up.”

Jamie Porter, 19, and her father James, 48, said whenever they walk their two dogs along San Gabriel Drive where the facility is located, they are followed by white Prius cars.

They said when they get half way up the street, they are usually “intercepted” by security guards who use clipboards to hide the logos on their shirts.

They allege one guard once told them “there are dog parks in Sunnyvale” after they threw a ball onto Apple’s grass.

Residents from the neighbouring houses have complained of strange noises.

The Porters, who can see the Apple facility from their rooftop, said it was unclear what was inside. “Just buildings, and there’s a big steel box; otherwise the fence is way too high,” Ms Porter said.

Her father said of the noises: “It’s almost like they want to do it under cover of night.”

Clues point to this being the facility where Apple is developing something auto-related — quite possibly its answer to Google’s self-driving car.

No longer a science fiction gimmick, driverless cars have been hailed as the next great leap in motoring technology that could transform the way we live.

The first trials of the technology in the southern hemisphere took place in November in Adelaide, with Volvo conducting a series of tests in conjunction with Flinders University, Carnegie Mellon University, the RAA and Cohda Wireless and Bosch.

Last month, Google was left red-faced after one of its self-driving cars struck a bus in a “minor crash”. It was thought to be the first case of a driverless car hitting another vehicle at the fault of the self-driving car.

According to the San Jose Mercury News, planning permit documents from 2014 and 2015 refer to an “auto work area” in one of the buildings and a “repair garage” in another.

The night-time noises could be explained by Apple taking advantage of cheaper off-peak electricity if it’s pulling lots of energy from the grid.

MIT engineer John Carrier speculated the mysterious hum could come from charging a high-intensity electrical capacitor. “I wonder if they’re trying to build up a lot of electricity to see if they could surge-charge a battery,” he said. “Could I charge a car up in seconds?”

Is Apple working on its own driverless car to counter Google?

However, a discussion on Hacker News threw up some other theories. Some suggested the whining noise could be a rolls machine or dyno — a treadmill for cars.

“They are used for running tests on vehicles and are outrageously loud,” wrote one user.

“They can be used during prototyping. In a car factory it’s at the very end of the assembly line and sometimes used for debugging vehicles that have come off the line with issues.”

Another took a different view altogether, suggesting the complex is actually a small data centre being constructed by converting an existing building.

“Large amounts of HVAC [heating, ventilation, and air conditioning] equipment for the size of the building,” they wrote.

“Cooling towers. Big fuel tank. Cummins Diesel emergency generator, size around 1MW. Lots of electrical conduit on outside of building. Picnic area and half basketball court.

“Several construction trailers on site, so some remodelling is going on. Beeping trucks and banging on sheet metal sounds like HVAC work.

“It’s annoying the neighbours because it’s directly across a drainage ditch from suburban houses. Nobody likes night-time industrial construction opposite their backyard.”

Whatever the truth, Apple isn’t saying.

A spokeswoman told the San Jose Mercury News: “Yeah, no, we’re not going to provide an official response,” but pointed out Apple’s “long history of developing auto-related products and services” for traditional cars.

Contacted by news.com.au, an Apple spokeswoman said she had “nothing to add”.

“We don’t have a comment for this story,” she said.