Covert listening device

Self-contained electronic covert listening devices came into common use with intelligence agencies in the 1950s, when technology allowed for a suitable transmitter to be built into a relatively small package.

By 1956, the US Central Intelligence Agency was designing and building "Surveillance Transmitters" that employed transistors, which greatly reduced the size and power consumption.

With no moving parts and greater power efficiency, these solid-state devices could be operated by small batteries, which revolutionized the process of covert listening.

[8][9] A "wire" is a device that is hidden or concealed under a person's clothes for the purpose of covertly listening to conversations in proximity to the wearer.

A stereotypical scene might include an individual being suspected by criminals of wearing a hidden microphone, and having their shirt torn open to reveal the deception.

[15] Not only microphones but also seemingly innocuous motion sensors, which can be accessed by third-party apps on Android and iOS devices without any notification to the user, are a potential eavesdropping channel in smartphones.

[1] With the Covid-19 pandemic came an increase in remote work spurring on a new advent of Employee Monitoring Software which remotely collects many forms of data from laptops and smartphones issued by employers, including webcam and microphone data, raising concerns that a new era of corporate spying has shifted the power balance between workers and businesses.

Researchers have also prototyped a method for reconstructing audio from video of thin objects that can pick up sound vibrations, such as a houseplant or bag of potato chips.

If a government body or organisation intends to use listening or recording devices they must follow the laws put in place by the Regulation of Investigatory Powers Act (RIPA).

Many people use listening devices on their own property to capture evidence of excessive noise in a neighbour complaint, which is legal in normal circumstances.

[37] Furthermore, the US passed the Wiretap Act which prohibits unauthorized interception of "wire, oral, or electronic communications" by the government or by private citizens.

Such laws were passed in response to congressional investigations that found extensive cases of government and private wiretapping without consent or legal authorization.