Is my phone listening to me? What is really behind those adverts
Almost certainly not. Researchers at Northeastern University tested 17,260 Android apps in 2018 and found none sending recorded audio. The adverts feel uncanny for a different reason: the apps on your phone contain trackers that report what you search for, buy, read and where you go. That is enough to guess what you were talking about.
By Archie Crossland, Head of Product and Growth at BLOKK. Updated 10 November 2026.
What the research found
The best known test is a 2018 study called “Panoptispy”, by researchers at Northeastern University and the University of California, Santa Barbara, published in Proceedings on Privacy Enhancing Technologies. They ran 17,260 Android apps from Google Play and three other app stores and watched what each one sent out.
Their finding on audio, in their words: “no apps appeared to exfiltrate audio in our tests”.
What they did find was different, and in some ways worse. Some apps were sharing screenshots and screen recordings of what people did inside the app, through outside code “without informing the user and without requiring any permissions”.
Two honest limits. The study is from 2018 and covers Android. And “in our tests” means what it says: automated testing cannot try everything an app might ever do. It did not prove that no app could listen. It found no sign that apps do.
So why do I see adverts for things I only talked about?
Because your phone does not need to hear you. It already knows a great deal.
- What you search for and read. If you talked about a holiday, someone in the conversation probably looked it up.
- Where you are and who you are near. Location data and shared Wi-Fi link you to the people around you. If your friend searched for a sofa in your living room, advertisers can connect the two of you.
- What you buy. Shops and apps pass purchase data to advertising companies.
- What you do inside apps. Many apps contain trackers from other companies that report which screens you open and what you tap.
There is also plain coincidence. You see hundreds of adverts a day and notice the one that matches something you just said.
What do apps actually collect?
Most apps include code from outside companies, built for advertising and measurement. This code runs whether or not you are using the app’s main features. It can report your device, your rough or exact location, what you do in the app and an advertising identifier that links all of it together across apps.
When BLOKK tested the first five apps shown for “free VPN” on Google Play in October 2025, they contacted 1,164 domains in their first minute, including advertising and tracking services, before the VPN had been switched on. That is five apps. A phone has dozens.
How to check whether an app is using your microphone
Both phone systems show you this.
- Android. Google’s help pages describe the Privacy dashboard, found in Settings under “Security and Privacy” or “Privacy”. It shows “which apps are accessing data, which permissions apps are using, and when that access is happening”. It covers the last 7 days on Android 13 and the last 24 hours on Android 12.
- iPhone. Apple’s App Privacy Report is in Settings, under Privacy & Security. Apple says it shows “how many times and when an app accessed privacy-sensitive data”, such as the microphone, over the past seven days. It needs iOS 15.2 or later.
Both phones also show a small dot or icon at the top of the screen whenever the microphone is in use.
If an app has microphone permission and no reason to need it, switch the permission off.
How to stop the tracking that is really happening
- Remove microphone and location permission from apps that do not need them.
- Reset or delete your advertising identifier in your phone’s privacy settings.
- On iPhone, choose “Ask App Not to Track” when an app asks.
- Block the trackers themselves. Permissions control what an app can reach on your phone. They do not stop the trackers inside the app from sending what it already has. A tracker blocker stops those connections leaving your phone.
Where BLOKK fits
BLOKK’s free Privacy Shield blocks known trackers in every app on your phone, on the phone itself, with no account needed. Activity shows you which apps tried to contact which trackers, and Map of Your Data shows the countries and companies those connections were heading for. It is the closest thing to seeing, with your own eyes, what your phone was doing when you thought it was listening.
Download BLOKK on Google Play or download BLOKK on the App Store.
