How It Works

How are telephones tapped?

Phone tapping enables people to listen in on conversations, either legally or illegally. It can be achieved in a variety of ways, each requiring different techniques and tools. Regardless of the method, all tapping techniques rely on exploiting a phone’s internal cabling, microphones and speakers.

The most basic method is to manipulate a person’s phone line outside their home or office. This is achieved by attaching a gateway phone onto the line by ‘piggybacking’ off the device’s cabling. This works as phones transmit audible noises (such as the human voice) as a fluctuating electrical current through their wires, which are encoded and decoded via handsets’ microphones and speakers. As such, by simply adding a splitter to any line and then plugging in another phone – ideally with its microphone wire disconnected – a line’s activity can be heard remotely. The advantage of this technique is that it’s incredibly easy to carry out and requires little in the way of equipment. The main downside is that physical access is needed to the line both before and during tapping operations.

The second, slightly more complex method of tapping a telephone involves installing a ‘bug’ in the handset. The bug is actually a minuscule radio transmitter that either through direct connection to the handset’s wiring – the same piggybacking process as before – or via the addition of a microscopic microphone of its own, is capable of picking up and transmitting a conversation and then broadcasting it wirelessly on a specific frequency to a receiver. This option enables someone to remotely monitor a phone’s activity without having to be in the locale, however it does require a greater level of access to the physical handset in the first instance.