How to find wiretapping in an apartment

There are many listening equipment available today. Despite the fact that wiretapping is considered illegal in the Russian Federation, you can easily purchase various types of listening devices on the Internet. Search statistics for purchasing bugs or hidden video cameras are growing - in 2022, there are more than 10,000 searches monthly. Therefore, you need to know how to find wiretapping in an apartment on your own. First, you need to determine whether you fall into the group of people whose information is of interest to attackers, find out what listening devices look like and where they are most often installed.

Who can listen to whom?

With the help of bugs, confidential information about a person is collected in many cases. They often spy on business competitors or their significant other, who is suspected of cheating. But they also collect hidden information in other cases:

to owners of private companies;
for people who have sensitive or secret work;
for lawyers, journalists, politicians;
to business partners;
in case of divorce proceedings;
in litigation involving large sums;
when visiting certain sites, including prohibited ones.

Famous people can also attract the attention of attackers, and it makes sense to collect incriminating data on them. However, knowing how to find a hidden video camera in an apartment, you can avoid close interest in your personal life and business negotiations. Leakage of personal or commercial information is highly undesirable for anyone, because it can lead to the fact that many personal plans will be upset and planned transactions will fall through. Therefore, if you belong to any of these groups, you need to regularly check your home for listening devices.

Detection methods

Hidden cameras pose the greatest danger. The audio recording is often unintelligible. It will also be unclear from the conversation whether the person knows about the hidden equipment. Such a tracking gadget receives both sound and video. This opens up new prospects for obtaining incriminating materials. A hidden camera allows you to get a visual view of your home around the clock and find the location of valuables. Advanced models can be activated by movement, the start of a conversation, or by time.

Self-examination

A thorough manual inspection of premises is a labor-intensive, cheap, and fairly effective method. Allows you to identify hidden cameras and bugs. Pay attention to switches, lamps, sockets, adapters, and small household appliances. Often, surveillance cameras, mini-dictaphones, and bugs are installed in computer components, system units, and desk clocks. Inspect the ventilation ducts, check the baseboards, gutters, and window frames. You can block data transmission from remote wireless models using a jammer.

Special devices

Radar will help determine the presence of a listening device and find it. It reads the radio wave field, detecting unauthorized sources. The key parameters of such devices are:

search modes for digital and analog bugs;
detection range;
operating frequency ranges;
presence of an interference filter;
amount of energy consumption;
duration of work.

The cost starts from 1-2 thousand rubles.

Choose a detector for searching video devices depending on the potential degree of threat, financial capabilities, and the importance of the information being protected. Detectors determine presence in several ways: field indication, optical and electromagnetic methods. Electromagnetic-type models allow for discreet investigation, but they are the most expensive.

Listening Installation Goals

Bugs are installed to collect hidden or secret information about a person or a competing company for which he works. For example, many people are interested in plans to acquire a company, merge companies, take them over, etc. Also of considerable interest is information that is classified as a trade secret: data on major contracts, innovative developments that can increase the profitability of the company.

But ordinary people should not relax, since even citizens who do not hold high positions can find a bug in their apartment. In this case, attackers are interested in information about where valuables are stored: currency, jewelry, important documents, gold, the location of the safe and access codes to it. In addition, sometimes specific information about one's personal life can be used to put pressure on a person to make a decision in which someone else is interested. Blackmail is also possible not only for the sake of obtaining material benefits, but also with the aim of forcing a person to commit a crime.

Where to look

Spy devices will be installed in places that offer the best view of the guest.

For example, you should look for cameras in the area of bathrooms, dressing tables and closets near which you will change clothes, beds, as well as spaces where you will most often pass or spend time: the bathroom door, the front door, corridors and hallways.

Take a good look at the places where you will have conversations. Sound recording devices will be placed closer to the object of observation: inspect tables, chairs, sofas, beds and balconies.

What devices are used for wiretapping?

The vast majority of individuals who collect information on competitors or simply other people use affordable, simple equipment. Often, bugs are small blocks that have a built-in data transmission module or internal memory for recording information. Detecting wiretapping in an apartment presents certain difficulties for ordinary people, because you need to know what to look for. It can be:

microphones that transmit information to remote devices;
audio devices for recording that are listened to later;
mini-video recorders with a recording function or transmitting information online;
devices that read data directly from a computer, phone, tablet, etc.

This equipment is miniature in size and is powered by batteries that support its operation for a maximum of 14 days. Devices can transmit a signal over radio over several kilometers, and over a network, such as WiFi, to anywhere in the world. Attackers plant a bug in your apartment and can listen to your important conversations or other secret information or see everything you do at any time.

Vibroacoustic listening devices - what do they look like?

Less often than those listed above, you can find devices that can intercept acoustic vibrations propagating from the ceiling, walls, and heating pipes. Vibration interception devices are called radio stethoscopes.

I wonder what vibroacoustic type wiretapping looks like? It looks like a miniature “tablet” connected to wires:

Sound waves cause vibrations in solid rock, and the device picks them up through walls for subsequent conversion into understandable information.

Types of bookmarks for listening

There are several types of bugs that are used to collect confidential information. GSM bookmarks are widespread - ordinary mobile phones without buttons. You can call them and listen to the room where this device is left, thanks to the auto-answer function. And when there is sound in the room, the phone can call the specified number. It is installed in extension cords, charging wires, etc.

Radio bookmarks are the most effective and widespread. They work like a simple radio transmitter, but can have many different functions. Vibrating devices are often used that pick up voice vibrations even through walls. Such equipment can also remove information from water pipes, windows, ceilings, etc.

You can mount a miniature Wi-Fi bookmark into any piece of furniture. Typically this is a high-resolution, bare-bones camera with a very sensitive microphone. It broadcasts video footage to a computer or smartphone via a wireless network. Infrared devices convert sound vibrations into light vibrations for transmission in the infrared spectrum.

It is very difficult to detect wiretapping in an apartment if it is a network bookmark. They are mounted in power lines, household appliances, sockets, extension cords and transmit information through the electrical network. They work indefinitely and are very reliable.

Laser bookmarks are also used to collect information, but they are not installed indoors. The laser microphone reads the vibration of window glass at a distance of up to 300 meters and transforms it into the sounds of ordinary speech.

In addition, more modern types of listening equipment can be activated remotely - by responding to voices when people start talking in the room or turning on at a pre-programmed time.

What different types of wiretaps look like

Let's start with the most popular ones, which most often have to be removed from the premises being inspected.

What GSM bugs look like

With the advent of cellular communications, the possibilities of acoustic eavesdropping have expanded. A GSM bug is a more advanced version of a radio bug. The radio bug is tuned to the desired radio wave to transmit information, and the GSM bug only needs to be within the coverage area of your mobile operator. GSM bugs most often work with a SIM card.

The appearance of the GSM bug may vary, but its design includes a microphone, battery, antenna and GSM module. All this can be placed in the device body. The device can be made in the form of a flash drive, keychain, or lighter. Any technique you use can be a “housing” for a bug. Most often, to detect such a bug, you need to disassemble equipment - a computer mouse, socket, printer, etc.

One of our finds is a GSM bug camouflaged as a computer mouse. This device allows you to listen to the room using any telephone. Found in a box with other computer accessories. It was discovered using a professional field indicator.

Now you know what a GSM bug looks like. Sometimes it's just a computer mouse that you use all the time.

Bugs with a SIM card allow you to hear everything that happens in the car or indoors.

What a radio microphone might look like

A radio microphone can also be installed in a computer mouse. It can also be built into a pen, another small item that we are used to carrying with us. Microphones for wiretapping are sold just like that – built into various objects.

A radio microphone or radio wiretapping, a radio bug is a mini-equipment with a radio transmitter, a microphone and a battery or mains power. I wonder what wiretapping with a radio transmitter looks like in its “naked form”?

Here's what a device that can be bought directly on the radio market might look like:

A radio microphone works as follows: sounds around the wiretapping cause vibration in the microphone membrane, the device amplifies the captured signal and transmits it to the radio using an oscillating circuit. The radio frequency is usually floating so that the signal cannot be intercepted accidentally.

The radio bug picks up signals at a distance of 100-300 m, so they are installed directly in the area of possible important conversations - near the workplace, in a meeting room.

They are quite common because they are inexpensive and do their job well. Their advantage is their high sensitivity, which allows you to record even a quiet conversation in a listening room.

The photo shows one of our company's finds - a microphone in a meeting room. It was hidden in the ceiling slats and was discovered during a visual inspection of the ceiling space.

What do wired microphones look like for wiretapping?

Acoustic microphones remain the most commonly installed listening devices. They are built into walls, into electrical and telephone sockets, into any equipment. It is most convenient for an attacker to install wiretapping so that it is unnoticeably connected to the power system, and the information is transmitted through wires.

It is difficult to say what wiretapping like a wired microphone looks like. It can be camouflaged as any equipment, for example, it can look like an ordinary capacitor on a monitor board connected to the network.

Wired microphone for covert wiretapping in an uncamouflaged form.

Most often, wiretapped microphones transmit information over the electrical network, radio network, and alarm wires. They appear in premises after renovations, rentals, and visits from various “services.” They are difficult to detect but easy to eliminate.

Here, for example, is what the microphone found by our ventilation specialists looked like:

It was installed in the supply valve of the ventilation system in the manager's office. The wire was laid inside a metal sleeve. Visually he was invisible. It was discovered using a nonlinear locator.

Where can listening devices be located?

Given its small size, hiding eavesdropping equipment is not difficult. Therefore, before you detect wiretapping in an apartment, you will have to carefully check many things and look even into small cracks.

The most common places where bugs are installed:

Niches and interior features - skirting boards, window sills, cornices, ceiling moldings.
Batteries, pipes, vents.
Computers, household appliances - speakers, TVs, etc.
Furniture - on cabinets, bookshelves, under countertops, under large furniture.
Decorative elements - photo frames, toys, figurines, table stands, etc.
Home textiles - wall hangings, curtains, roller blinds, curtains.
Electrical power points - sockets, switches, chandeliers.

You can also receive a wiretap as a gift - it can be embedded in a present presented by business partners or acquaintances: in a telephone, a beautiful souvenir, a stand for stationery, or a computer mouse. It should be taken into account that listening devices are usually not hidden in places where there will be interference for good audibility - under sofa cushions, inside cabinets, cabinets.

What to pay attention to

If you have any suspicions that you may be the object of close attention from strangers, first make sure that someone is actually watching you or listening to your private conversations. For example, your neighbor or business partner let slip information concerning you that you did not tell him, and he could not hear it anywhere. If information appears in the media that no one knows except you and your loved ones. Pay attention to noise when talking on the phone: minor sounds, delays in other people's speech, changes in volume, hissing. All of these could be signs of eavesdropping.

You should also be wary if your apartment was robbed, but nothing really valuable was stolen. Check that the front door is closed and ask your neighbors to pay attention to this. If any of the above situations occurred, you should ask yourself how to check whether there is wiretapping in your apartment and how to identify foreign devices. You can do this yourself or turn to professionals - then the check will be 100% effective.

Objects vulnerable to the installation of spyware

Do all the devices and accessories in your room match other objects in your room or throughout the house? Are any of them located in strange places or in strange ways? Do they change from room to room?

Pay attention to smoke detectors, thermostats, outlets, plumbing fixtures and light bulbs. Common sense dictates that all of these devices should be similar to each other, since they usually appear in a room or building during construction.

This observation may reveal an anomaly that is worth investigating further. Are there similar devices in different rooms that are located in strange ways or in strange places? When examining a room, you should ask yourself questions like these and probe further if you have any suspicions.

Do the paintings match the decoration or style of the room or home you are staying in? Most often, hotels and rental homes have a common decorating style.

For example, in a modern hotel, the decorations, fixtures, furniture and fixtures are likely to be modern. A rural bed and breakfast may have more decrepit furnishings with period charm. Pay attention to plumbing fixtures and decorations that are suspicious.

How to look for wiretapping in an apartment on your own

You can conduct a search yourself, although there is no guarantee that you will find anything, since cameras and transmitting devices are becoming smaller, and microphones may not attract your attention at all. There are several ways to search for wiretapping that are worth using. However, remember: if nothing is found, this does not mean that your apartment is not being bugged.

Visual inspection

First of all, it is necessary to conduct a thorough visual and physical inspection of the most obvious places where bugs can be installed: cornices, floor and ceiling baseboards, ventilation holes, pipes. Check the furniture, cornices, curtains, paintings, vases, figurines, and other interior items.

Inspection of electrical appliances

Inspect sockets, lighting fixtures, switches, and adapters. If they are slightly shifted or show signs of damage, then they need to be checked first. Disassemble them with the electricity turned off and pay attention to unnecessary parts. Some devices require a power connection, therefore, during installation, certain things may have been moved from their usual places. In addition, new items could appear.

Checking Wi-Fi networks

Check available Wi-Fi networks. If there is an unknown person on their list that cannot belong to neighbors or a nearby cafe or store, then they need to check to identify cameras or wireless listening devices.

Detecting a video camera using a flashlight

The installed video camera can be found using a regular flashlight, because its lens has glare. You should turn off the lights, draw the curtains, turn on the flashlight and carefully inspect the walls, furniture, and interior items. If glare is visible somewhere, it may be a hidden camera.

Check your mirrors

It is recommended to always check all mirrors in the room to ensure they are not double-sided. The best way to check is to use your finger. The reflection of your finger in most mirrors will not make contact with your finger if you press it directly into the mirror. There should be a gap of about 5 mm between the reflection and the finger.

If you touch the mirror with your finger and the reflection in it comes into contact with your finger, you need to study the mirror in more detail.

It's important to note that places like bars or gas stations may use metal-based mirror film instead of regular mirrors, which looks like a two-way mirror. This is done in order to avoid possible glass fragments that could be dangerous for visitors.

Another test technique is to turn off the lights and shine a flashlight into the mirror to see if there is anything behind it.

How to check electronic devices

They need to be disassembled to detect wiretapping. It is important to remember that electronic equipment creates interference itself. It will be very difficult for a non-specialist to find a bug in it. Most often, foreign eavesdropping devices are installed in a landline telephone or computer monitor.

When checking and searching for listening equipment, you must be careful, as attackers may guess about it. Then they will turn off the wiretapping, and it is almost impossible to find a non-working device.

Telephone listening devices - what do they look like?

It’s not easy to answer what wiretapping a phone looks like, since there are so many options. We have learned to listen to mobile phones, landline phones and IP telephony, the transmission of information through which passes through completely different communication channels.

A landline telephone has a wire through which information flows. It is clear that you can embed into it to gain access to the conversation. The wiretapping device is connected to a telephone handset, where you can install a radio bug or a voice recorder, which is convenient since changing batteries is not required - the wiretapping circuit can be powered from the device’s wire. You can also wiretap the device or wire. You can intercept a conversation without even getting into the apartment - a bug can be inserted into an interfloor box, into a distribution box or into a telephone socket. It might look something like this:

You can also cut into the telephone wiring and install a bug, which is usually installed in sockets.

Equipment for searching for wiretapping

To find bugs in an apartment, you can buy special technical devices of varying prices. These are a radio wave detector with sound indication, detectors of hidden video cameras, field indicators for identifying active bugs, non-linear locators, and sets of search equipment. The devices can track foreign electronic devices by detecting their electromagnetic signal.

When choosing, you need to pay attention to their operating frequencies, maximum range, power supply parameters, battery life, dimensions, temperature conditions at which the device will function normally, and some other parameters.

Professionals use more complex multifunctional search devices and expensive radio monitoring systems to continuously check radio broadcasts and identify radio microphones with complex operating patterns. Spectrum analyzers, nonlinear locators, amplitude bearing devices and other devices are also used.

How does car wiretapping work?

To collect information and wiretap, devices such as:

Dictaphone.
Mini camera.
Microphone transmitter.
Tracker with audio monitoring function.
Hydroacoustic sensor.

Either the information is recorded on a memory card, or this data is transmitted directly online. They can work for a long time without charging. And some spy models are connected to on-board power. These listening devices can transmit audio, video, photos, as well as vehicle location data. Many trackers are activated either by a motion sensor or by voice recognition.

Help from professionals

If you couldn’t find the bugs on your own, contact a professional. offers services for searching for wiretapping in an apartment with complete confidentiality and legality of the actions performed. Specialists with higher education in the field of information security will promptly and responsibly check the premises for the presence of listening devices. 20 years of experience and professional equipment allow us to find bugs even in the most difficult cases.

Some tips when contacting our company:

do not tell anyone about your intention to check the apartment and do not tell the date of the inspection;
when ordering or discussing inspection details, you must not call from the premises that need to be inspected;
Explain to your loved ones that scheduled repairs are coming;
provide our specialists with full access to all rooms and other areas of the apartment.

The search is carried out by professionals with experience in intelligence services and the necessary knowledge in the field of information security. They will do the job efficiently using specialized equipment and provide complete information about the presence or absence of wiretapping.

What about thermal imagers?

Another device that helps in detecting tracking equipment that you need to know about is a thermal imager. Any tracking device, whether it records video, audio, or emits infrared rays, will also emit some kind of thermal radiation, which is easy to detect with a thermal imager.

Most security cameras get quite hot due to their small size and because they are usually hidden inside some object that does not arouse suspicion and does not provide good ventilation.

You can use, for example, a device such as FLIR ONE Gen 3 - it connects to a smartphone and allows you to use it as a thermal imager.

This thermal imager will allow you to find hot spots in a room using your phone. Once you find such a point in a wall, behind a painting, in a smoke detector, behind any other device, or in any other location that seems unusual or suspicious, you can investigate the anomaly. It would be wise to thoroughly inspect the area for tracking devices.

Advantages of contacting our company

By contacting us, you will receive a free consultation by phone or online. We approach each order with full responsibility, take into account all the nuances, and use an integrated approach. We search for bugs in the apartment, guided by the principles of confidentiality and legality. We use special equipment, so we find all types of listening devices, regardless of what operating mode they are in - active or “sleep”.

We offer optimal prices, and the cost of the service depends on the characteristics of each situation. We provide services in Moscow, the Moscow region, and travel to the regions. We conduct an apartment inspection at a time convenient for you. We will provide high quality services. We will find and neutralize bugs in your apartment.

Precautionary measures

Most likely, the room will be clean, but if a camera or bug was discovered, you need to get out of their sight and call the police. Perhaps the attacker got into the frame and can be identified, and unnecessary movements in the frame can erase an important fragment located at the very beginning of the recording.

Technology does not stand still, so some devices may go unnoticed. Just look at the development of researchers from Peking University - in 2022, they attached a robot spy to a sticky fish.

Have you ever felt like you were being watched? You can tell your stories in the comments and, of course, in our Telegram chat.

A few rules to protect yourself from wiretapping

To protect your confidential information in the future, try to follow these simple rules:

do not talk on the phone about topics that may contain personal or sensitive information;
limit access to your apartment for unverified people;
check gifts from partners for bugs;
do not take things lightly that are allegedly forgotten by visitors, because even a keychain or pen can be wiretapped;
regularly check baseboards, sockets, furniture, cornices, etc.;
Do not leave your mobile phone unattended where third parties can take it.

You can install a device that protects against wiretapping in order to create interference, noise, encode speech, that is, nullify all the efforts of attackers.

Experts will recommend what information security measures should be taken. They will provide high-quality technical protection for your apartment, because special information and timely measures taken helped to reliably protect the homes of clients who previously contacted us.

Preparing for the search

Experts advise entering a new room with the initial assumption that it is under surveillance. There is no need to panic, because it is similar to fastening a seat belt in a car - most likely, it will not be needed, but it will make you more confident in your safety.

The room should be divided into four sections and each of them carefully examined for suspicious details. They can be the same things like coffee pots, exposed wires, suspicious light bulbs - you should pay great attention to all of this.

Directional microphone

They are also divided into several types:

Tube microphones are tube-shaped devices with holes arranged in several rows to capture sound vibrations. At the end there is a microphone, a signal converter and a voice recorder for recording.
Gradient devices have two microphones next to each other, which also convert sound waves from the difference in the values they capture.
Phased arrays have multiple microphones that pick up sound and transmit it to a transducer.
Parabolic microphones are the most common type, consisting of a concave dish of 20 cm in diameter. In the center of the dish there is a signal receiver, which already transmits data to the recording device.

All such data collection devices record all sound, i.e. not only conversation, but also the rustling of leaves, rustling of packages, etc.

conclusions

To detect a professional listening device, it is better to invite professionals who will at least have a chance to remove the wiretapping in the office, so that you no longer have to worry about disclosing trade secrets to competitors.

And remember, timely protection of your premises or office from listening devices can save a lot of karma, material and monetary values and your peace of mind.

See similar materials:

What types of bugs are there for wiretapping?
Thermal imagers - what are they?
Phone wiretapping and computer monitoring from neospy
Examples of disguised spy wiretaps
Smartwatches for adults - how to choose what to watch

Telephone audio signal repeaters

A parallel telephone is placed anywhere on the target telephone line pair. For telephone eavesdropping, a parallel installed bug is activated when the telephone line is in use. Do these radio bugs require a microphone to hear a telephone conversation? Since speech is already in electronic format, parallel wiretapping converts sound signals via electrical lines, therefore, a microphone is not needed.

Where is the best place to install such eavesdropping equipment? Telephone bugs can be installed within a telephone line, anywhere along a telephone line within a building or home, on a telephone pole, distribution cabinet or terminal room in an office building where many lines are connected to electrical wires. Like telephone repeaters, parallel telephones do not require the use of batteries. The telephone repeater is powered by voltage on the telephone line.

In our catalog, you will find spy gadgets that are especially useful for companies that have large premises or offices and want to monitor the conversations of strangers. We recommend that you consult with one of our specialists to find a specific solution to your needs. We have technicians who can evaluate whether it is possible or not to implement your request.

How can I order this tracker?

These spy trackers are currently in the public domain. It is quite possible to purchase such a bug for a car even from car alarm sellers. Compared to a car alarm, a bug will cost a little more, but such a tracker is very useful and easy to use. You only need to install it once, and you don’t need to do anything afterwards. This bug will be powered from the on-board network.

A car alarm is not suitable as a full-fledged spy bug. For example, if a jealous spouse decided to install wiretapping in the car. Installing such equipment can be quite difficult. It will not be possible to use only one tracker module, since it cannot work in parts. Therefore, for these purposes, it is best to purchase an independent GPS GSM tracker with a microphone.

This thing can be viewed in the online store in the spy stuff section. Due to the fact that the tracker is not a special device, it is sold in many places. If you can’t find a suitable mini-bug on the Internet, you can look at automotive electronics stores and the car market.

By the way, it is worth noting that bugs can also be found on the popular AliExpress website. In Russia, such bugs are also made, so it is recommended to first look at domestic devices.

UHF listening devices

Professional radio bugs that use ultra-high radio frequencies and are designated UHF (UHF), operating at higher frequencies above 400 MHz. The main advantage over GSM and FM bugs is the sound quality, you will get completely clear audio with almost zero distortion and ultra-miniature dimensions. One of the main disadvantages is the need for a special receiver to be within range of a UHF listening device. There are many uses for UHF bugs, which can be installed on objects or simply disguised in a 220V power supply.

UHF radio microphones for indoor listening make up the vast majority of spy bugs. Voice-activated radio bugs are common. That is, when the voice is heard, the transmitter will automatically turn on. It will also turn off if there is no conversation for a certain period of time. The device will use the battery sparingly, and the listener will not need to change batteries for several days or months. The downside of this technology is that it does not respond consistently to ambient sounds, because The conversation may not be loud enough to turn on the device, and extraneous sounds are also affected, causing false activations. Some gadgets have an adjustment function that will allow you to set the desired switching threshold. Radio microphones of the same type can be equipped with remote control to turn on the transmitter. As a result of remote control, the listener himself determines when to turn on the device so as not to miss an important conversation. In addition to saving battery, this type of bug is advantageous because the detector cannot detect listening devices if it is turned off. Therefore, it can be turned off at certain times to remain undetected if necessary.

Disguised bugs are one of the most successful types of spy technology. These radio bookmarks are usually installed under the guise of ordinary home or office items. For example, a regular desktop calculator or computer mouse contains a miniature radio bookmark for listening.

Finding a bug using a visual inspection of the car

To find listening devices, of course, you can examine your car from all sides, but first, it’s still better to look in all the most secluded places. And if you manage to find a spy, then only if it was installed unprofessionally. And if it was installed by specialists, not in a hurry, then the likelihood of a search is small.

A regular tracker is most often installed under bumpers or magnetized under the bottom. It is a black box, about the size of a matchbox. There is also a possibility that the tracker could be installed inside the car. Therefore, it is recommended to first look under the seats, and only then you can visually inspect other places, but at the same time you need to imagine where this bug can be hidden in the attacker’s place.

It is worth noting that the most popular places for installing a spy are: seat trim, car seat, dashboard and many others. But before you start disassembling your car yourself, it is best to entrust this work to professionals with special equipment.

A Brief History of Bugs

Eavesdropping has been practiced since time immemorial. Even during the times of the Roman Empire, spies eavesdropped on the conversations of opponents, making their way into palace chambers and imperial palaces. However, it quickly became clear that ears alone were not enough. One of the first methods of eavesdropping was special acoustic channels built into walls, which made it possible to receive information even from distant rooms.

More advanced listening methods only appeared during WWII. They were used by the Third Reich and the USA. Due to the large size of the listening devices and the cabling required, it was very difficult to hide the equipment from prying eyes. For this purpose, chandeliers were most often chosen, which in most cases did not attract the attention of interested parties visiting the offices.