A New Privacy Threat
Researchers at Pennsylvania State University have uncovered a startling vulnerability in modern communication: radar sensors can eavesdrop on phone conversations by detecting the minute vibrations inside a smartphone. When someone speaks on a call, the phone’s earpiece speaker generates subtle internal vibrations. Although humans cannot see these movements, highly sensitive millimeter-wave radar detects them from several feet away.
Turning Vibrations into Speech
The team built a system that captures these vibrations and translates them into speech using advanced artificial intelligence. They combined radar signals with a modified version of OpenAI’s Whisper speech recognition model and successfully reconstructed significant portions of conversations. Their approach, called WirelessTap, achieved around 60 percent accuracy at distances of up to three meters, enough to expose words and phrases that could compromise privacy.
Everyday Technology, Extraordinary Risks
What makes this finding even more concerning is that off-the-shelf radar components—already common in vehicles and consumer electronics—make the technique possible. As radar technology grows smaller and cheaper, attackers could hide sensors in everyday objects and use them to listen in. The researchers warn that even partial reconstructions of speech, much like lip-reading, still provide enough context to reveal sensitive information.
Preparing for the Future
The study does not just highlight risks—it also raises awareness. By revealing how radar can be weaponized, the researchers aim to encourage the development of defenses before malicious actors exploit the weakness. Engineers may need to redesign phone hardware, shield components, or create detection systems that alert users to hidden radar surveillance.
Why It Matters
This research shows how radar technology, when combined with artificial intelligence, threatens personal privacy. Our conversations may now be vulnerable in ways we never imagined, and proactive protection has become more urgent than ever.
