Yes, Your Phone is Eavesdropping on You – and Most Americans Don’t Know How to Stop It

Study by NordVPN reveals majority of American consumers in the dark on sonic snooping by devices

Half of Americans (53%) say they have seen an ad for a product or service pop up on their phones soon after talking about it or watching it on TV, new research by cybersecurity company NordVPN reveals.

Two in four (50%) consumers admit they have no idea how to prevent this from happening and one in ten (10%) who noticed the adverts said it scared them.

Rather than devices reading your mind, this personalised product placement is due to a type of data monitoring called ultrasonic cross-device tracking. This is where apps on your smartphone listen in to background noise — including conversations — to gather more information about you.

“Later, they share this data across other devices,” says Adrianus Warmenhoven, a cybersecurity advisor at NordVPN.

Smartphones were by far the most common place to find these tailored ads. Four in five (77%) Americans who recognised the phenomenon first spotted it on their handset, with half (52%) seeing it on their computer and a fourth (39%) on their tablet.

Information showing people’s behaviour across devices is extremely valuable to companies, but this type of tracking is controversial because of its lack of transparency and security concerns around consumers’ data.

A key part of cross-device tracking is the use of audio beacons, which are embedded into ultrasound — frequencies above the level that can be heard by humans — and can connect with the microphone on our devices without us knowing. This is one reason many apps ask for permission to access your smartphone’s microphone, even if they don’t involve using your voice.

“While it’s impossible to stop the ultrasonic beacons working, you can reduce the chance of your smartphone listening for them by simply restricting unnecessary permissions you have granted to the apps on your device,” says Warmenhoven.

Ultrasonic Cross-device Tracking — How Does It Work?

Ultrasonic cross-device tracking is used as a method to link all the devices you own to track your behavior and location. These ultrasonic audio beacons can be embedded in many things we interact with daily: TV shows, online videos or websites, or apps on our phones.

Imagine you are watching TV and you see chocolate being advertised. You pick up your phone, and the same chocolate ad appears on your screen. By using ultrasounds, audio beacons can detect when your phone is nearby, and apps on your phone can listen for approximate audio beacons to track what you are doing.

How Can You Reduce Cross-device Tracking?

NordVPN cybersecurity advisor Adrianus Warmenhoven has some top tips to keep snooping devices at bay: