How to Bug a Room With Bluetooth

So you want to be a spy? Well, one of the tools a spy occasionally employs is called a bug. It can be as simple as a microphone hidden somewhere in a room where your enemies are consulting. These are instructions on how to make a relatively simple wireless bug.


Seriously reconsider.

Eavesdropping is rude! But if you just have to do it, continue.

Turn on your Bluetooth headset.

Make sure it is paired with your phone, and that the battery is reasonably fresh.

Hide the Bluetooth headset somewhere in the room where it will be able to pick up sounds clearly, but make sure that it is well hidden.

Leave the room, but don’t go too far; your Bluetooth connection should work through walls, but if you get too far away, it won’t work very well.

The range is about 30 feet, or 10 metres.

Wait for the conversation of interest to start.

When it does, turn on the voice recorder on your phone. It should record through the microphone of the Bluetooth headset.

At the end of the conversation, stop recording.

If the phone stops recording automatically after a while, you may need to start it again. Retrieve the headset and play back at your leisure.

Optionally, use a microphone and Audacity, a free, open-source audio recording application, to dub the conversation to your PC.

From there it can be emailed, or burned onto a CD.


  • The range of a bluetooth device is about 30 feet, or 10 metres. To test it, place your phone somewhere you can see from a distance, make a call, and see how well you can converse with the other person for 10-30 seconds at 6 feet or 2 metre increments. If possible, place the phone where you’ll be placing the headset and see just how far away you can get while the voice is still clear.
  • When placing the headset, consider where people will probably be standing in the room. If there is a television or a radio, consider that these may drown out the conversation (and might actually be used with that in mind, so you, outside, cannot hear what is going on). If the headset is closer to the people talking than the television or radio, chances are you will hear more.


  • People may be offended if they find your equipment… or you.
  • It is illegal in the United States to make a recording of somebody without their permission, and depending upon what you do with the recording, you could find yourself in trouble.
  • Evidence of a crime obtained this way is inadmissible in court for the above reason. It’s only legitimate if the subject knows they are being recorded.
  • This could be an excellent way to give away a $30 piece of equipment to someone you don’t trust.
  • Never, ever, use this method to record intimate relations. The legal consequences of that are much more severe, not to mention the personal consequences.

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