Today’s phone microphones are perfectly adept at picking up sound in all sorts of conditions, and they’re backed by all kinds of processing techniques to filter out noise and capture clean audio. [mcore1976] has been working on a device to jam phone microphones that might be listening in, however, countering fancy processing techniques in turn.
The build uses a microcontroller brain to control an array of ultrasonic transducers. [mcore1976] has created many revisions of the project, each time improving its ability to jam microphones in modern hardware. The latest revision uses an RP2040 microcontroller and a MOSFET drive stage to control 20-80 ultrasonic transducers. They’re driven with a PWM signal generated from the RP2040 itself. The signal output is specifically modulated to try and confuse the automatic gain control systems used in many modern phones in order to make it difficult for them to record clear audio when the jammer is running. As [mcore1976] demonstrates with an iPhone 17, his voice is completely lost amidst unintelligible garbled noise while the jammer is switched on.
It’s a niche idea, and perhaps most interesting because it affects phone microphones while being largely inaudible to the human ear. We’ve featured other interesting jamming devices of late, too. Video after the break.
I recall a college project which was two wrist band bangles made of ultrasonic transducers as a means of mic jamming with a fashion accessory.
I have made one of these. It does work, but the range is incredibly short, it is large, highly directional, can be blocked by clothes, and some people can hear it. It also makes some people feel ill.
“It also makes some people feel ill.”
None in a consulate I hope.
Might be fun to go hang out in an Apple store with one of these in my pocket.
How many people are recording audio in an apple store and what do you want to accomplish?
https://www.youtube.com/watch?v=J-SH18dtBlY
The cone of silance is here. Shhhht.
With the advent of video glasses that can record anything anytime, this tech might provide a modicum of privacy.
I dont think cats and other pets won’t appreciate this device, if some people can hear it cat surely can
Like one of those ultrasonic pest repellents?
I recall Naomi Woo making a neck lace full of those transducers and being able to block recording from near phones., Sighs, I miss that girl ,for the right and the wrong reasons.
I had to have a microphone jammer for my prior line of work. What I used was the propane tank with the cyclops heater. This was proven effective to make any microphone diaphragm flutter making the speech unintelligible. I would stand next to the heater and in the summer I used a Kenmore HEPA filter the size of a 5 gallon bucket.
Hello guys. I am the creator of this project. It currently completely jams all of android phones and most of iphones including the newest models from couple of meters. The concept was to provide a bit of privacy in current environment full of devices spying on you. Yes this is a niche project but I think you may need such kind of device at some moments in your life. The platform is open and the source code and the design may be modified according to your needs for example remote activation of the jammer or activation only when human voice detected
ok, i’ve read the article, not watch the video, i wonder if a simple low pass filter run over the recoreded data wouldn’t get rid of the noise, i mean, you can’t hear anything in the raw data, but after passing it through a filter? being the fact that the jammer is ultrasound, seems easily cleaneable if someone really wanted to spy and had some electronics knowledge right?
this is not as easy as you think. The point is that the jammer is not generating just a simple noise. Consider that iPhones have AI system and up to 4 microphones to get the human voice right. It took me 5 years to figure out how to jam it in proper way. That is why commercial microphone jamming solutions cost 1000+ USD and… I am giving you all of this knowledge and fully working solution FOR FREE :-) Try to build the newest version, you will be amazed