As the technology behind recording devices becomes more advanced, the devices themselves become more powerful, yet also more discreet. As a result, it is harder than ever to detect them. Luckily, many commercial detectors are available that allow you to locate even the most effectively hidden recording devices.
The first step in identifying recording devices is to purchase a radio frequency (RF) signal detector. Different variations of this type of detector allow you to identify small cameras, phone-tapping recorders, and other recording devices, which emit RF signals. As of 2009, prices range from about $19.99 for a standard RF signal detector all the way up to $199.99 for a detector that can find a wider variety of recording devices.
When using your RF signal detector, it is important to unplug or remove the battery from all other electronics in the room. Many household devices, such as your cell phone, TV, computer, stereo, radio receiver, and video game system, that can also emit RF frequencies that will confuse the detector. Eliminating any potentially conflicting frequencies allows you to isolate the devices you are trying to find.
How your RF signal detector alerts you to the presence of a device emitting a signal depends on the model you purchased; most commonly, such detectors emit a series of beeps or flashing lights. The device will indicate not only that it has identified a signal, but also the signal's strength. Move in the direction where the signal gets stronger: the signal will be strongest at the location of the device emitting the radio frequency.