When Apple released a software update at the start of November that enabled its new hearing aid features in AirPods Pro 2 earbuds, Rithwik Jayasimha immediately went out with his dad to buy a pair for his grandma. “We came back home, we took them out of the case, and I was looking for the feature and it was just missing,” Jayasimha says. India, where Jayasimha and his family live, is not currently one of the many countries where Apple’s hearing aid features are available. “It was a huge bummer,” Jayasimha says.

Instead of abandoning the headphones, Jayasimha and two friends, Arnav Bansal and Rithvik Vibhu—both of whom say they have grandmas who use hearing aids as well—hacked together a way to bypass Apple’s location restrictions and enable their hearing aids in Bangalore.

To dodge Apple’s geolocation restrictions, the trio built a rudimentary, signal-blocking Faraday cage on top of a microwave with aluminum foil, which ultimately allowed them to enable the hearing aid settings. “We don’t even think it’s Apple’s fault. The feature is amazing,” Jayasimha says.

The group, which has a mixture of hardware and software skills and first detailed their hack as part of a technology collective called Lagrange Point, say a couple of dozen people have contacted them asking for help with their AirPods. “We’ve got a huge amount of interest from folks in India who have these AirPods or whose grandparents need them and they’ve not been able to use them,” Jayasimha says. Others have documented the same issue in social media posts.

The researchers demonstrated that they could bypass Apple’s geographic restrictions with a set of AirPods Pro 2 connected to a 10th generation Wi-Fi-only iPad. They note that it would be possible to do the workaround on an iPhone or iPad connected to a mobile carrier as well, but it would be more involved.

To find the workaround, the researchers first looked at the different ways that iOS establishes where a device is in the world. For Wi-Fi-only devices, there are a few checks. The server looks at which Apple Store region the device is connected to, as well as the timezone, language, and region the device is set to. Additionally, the operating system sends a simple web request to an Apple web service that then responds with the country code of the country the device appears to be in based on the location associated with its IP address.

The researchers first tried manually changing the time zone and region settings for the iPad, but it ultimately wasn’t clear whether this impacted their ability to hide the iPad’s true location. When masking the iPad’s IP address so it would appear to be connected in the United States didn’t work, the researchers assessed other metrics the device might be using to establish its geographic location. It turns out that iOS also examines Wi-Fi “Service Set Identifiers” or SSIDs that help devices connect to the right Wi-Fi network when there are many network signals in the air—like in an apartment building or at a coffee shop.

The operating system also uses GPS triangulation and device identifier “MAC addresses” of nearby devices, including routers, to establish a device’s location. In other words, even if a person in Bangalore uses a proxy to make it seem like their iPad has a US-based IP address, all the nearby routers and devices are associated with India-located IP addresses that give the real location away.

To deal with this, the researchers rigged up a Faraday cage, which blocks electromagnetic signals, to isolate the iPad from the other devices and wireless networks around it. They built their aluminum foil-clad enclosure on top of a regular kitchen microwave and then turned on the microwave whenever they wanted to block signals to the iPad. The setup worked because consumer microwaves heat food using electromagnetic waves that are at the same frequency as Wi-Fi signals—2.4 GHz. Essentially, the researchers had turned their microwave oven into a Wi-Fi jammer.

“We put several layers of aluminum inside and outside [a cardboard box] and we’d see some signal strength drop,” Bansal says. “Of course, it’s not going to be great, but combined with the microwave, it worked.”

Ultimately, the researchers designed a less ingenious, but simpler and more reliable Faraday cage to make their manipulation more practical. With the iPad placed in its own shielded bubble, the researchers used an open source Wi-Fi location database and Wi-Fi SSID cycling tool to trick iOS into locating the iPad in California. With this complete, the AirPods could work as hearing aids in India.

Apple currently offers the hearing aid features in more than 100 countries, and it has great promise as a tool for making hearing aid tech more accessible—and more palatable—to millions of people around the world. But the company isn’t able to offer the feature everywhere and restricts access in certain countries, like India, likely because of regulatory hurdles related to medical devices. The fact that it’s possible to circumvent these restrictions may offer a solution, at least temporarily, for people in blocked countries who are looking for a workaround.

Apple did not return WIRED’s request for comment about the findings, but the researchers note that it seems like it would be possible for Apple to close the loophole they discovered fairly easily. They say they haven’t heard from the company.

Alan Woodward, a cybersecurity professor at the University of Surrey, says their work is “very interesting” and demonstrates how there may often be ways around “safeguards” put in place by Big Tech. “It shows that those with the technical understanding can bypass the geofencing of apps relatively simply,” Woodward says. “Not that everyone could do it, but they probably know someone that can.”

“I’m not sure how many people realize the number of variants in something like iOS even on what is apparently the same version—the build number is what really matters,” Woodward says. “It’s more a lesson to people that you have more than you realize on your phone.”

Services offered by Big Tech companies such as Apple and Google often have had staggered launches around the world as lawmakers have introduced regulations to control technology companies’ power and protect people’s rights. In the EU, for instance, several AI products have been delayed or not launched due to strict privacy laws. Apple has also been required to allow alternative App Stores due to EU rules. At the same time, right-to-repair movements have grown in popularity, and people have increasingly been hacking into the products they buy.

While the three researchers in India believe that it is likely Apple’s hearing aid features will officially come to the country in the coming months, they plan in the meantime to help the dozens of people they say have reached out to them about their own headphones. They also plan on using the second version of the Faraday cage to set people’s AirPods up. From their own grandmas’ experiences, the hearing aid features appear to be valuable in their everyday lives.

Bansal says his grandma has some hearing loss and other health challenges, but has typically worn hearing aids while watching television. “She used to wear her old clunky hearing aids, and they were really problematic because they had these tiny little buttons on them,” Bansal says. “But now she uses the AirPods, we’ve set it up with her hearing profile, and she can use it to watch the TV just fine and it’s a lot nicer. She doesn’t feel like a patient wearing it.”