Audio Recorder Smartphone Microphone Jammer GTG-2020 Voices /w external speaker


99 Items


More info

The Professional Choice

Since 2006

Worldwide shipping
Immediate customer support
1 YEAR Warranty

Audio jammer Ultrasonic + White Noise Suppressor (External Speaker Option) GTG-2020

7 ultrasonic transducers, Super-effective Virtual Wall system, voice imitation, Turbo mode, 100% jaming!!!

"GTG-2020 Voices" Improved version that provides an even more effective defense! New model retains all of the advantages of its predecessor, interference system got improved, two additional ultrasonic transducers and a jack for an external ultrasonic speaker were added.

 The device is designed to protect conversations areas from eavesdropping. Device blocks wireless microphones, tape recorders, RF transmitters, hard-wired microphones and most of professional digital tape recorders including tape recorders installed in mobile phones (smartphones). Ultrasonic inaudible noise signal as well as acoustic speech-like noise signal are used in jamming the eavesdropping devices. ​​​​​​​


   Effectively protects against eavesdropping and recorders. Protect confidential conversations, meetings, business conferences and secret meetings against eavesdropping.

Microphone jammer GTG-2020 Voices with 7 ultrasonic transducers — new 2019 model with an improved jamming system and an option to connect an additional external ultrasonic speaker. It has 2 additional transducers on the top panel that create a "virtual wall" for maximum protection from sound recording devices. Device blocks any microphones, dictaphones (including professional ones) in the range of 7 meters (23 ft) and at even greater range when using the external ultrasonic speaker. For a maximal efficiency of ultrasonic interference it is advised to engage "TURBO mode". Acoustic interference volume can be adjusted (and even turned off for a completely silent operation), power can be supplied through a 110V/220V power source or built-in battery.

Key differences from the old model:​​​​​​​


New jamming system. "GTG-2020 Voices" has a new ultrasonic pattern that guarantees even more reliable jamming of spying equipment in its range.


Two vertical ultrasonic transducers create a "virtual wall" In addition to 5 transducers on GTG-2, the new model has two additional transducers located on the top panel of the device. Emitting interference in a vertical direction these two transducers create a "virtual wall" that protects you from any microphones or dictaphones located behind it.

Ability to connect an additional ultrasonic speaker. In comparison to "GTG-2020 Voices" that supported only acoustic speakers to amplify the acoustic interference, the new model supports connection of ultrasonic speakers via mini-jack cable. Working with an additional speaker "GTG-2020 Voices" efficiently suppresses even hidden microphones, which are located outside the range of seven main transducers. For maximum efficiency additional speaker can be placed on the side of the speaking person (so that transducers are pointed at him from different directions) or under the table.

Capability to connect one or two additional ultrasonic speakers makes "GTG-2020 Voices" even more effective in protecting oneself from audio espionage (Attention! Package include the additional speaker)

Additional external ultrasonic speaker for GTG-2020 for Super-effective ultrasonic jamming 

Advantages of "GTG-2020 Voices":


Acoustic speech-like interference guarantees 100% confidentiality. In addition to ultrasound, the new model has a powerful speech-like interference that generates randomly and makes eavesdropping completely impossible. You can't filter out such interference even on the modern equipment, so no matter what adversaries do they will only record meaningless noise instead of your conversation. You can be 100% sure in your safety!

Upgraded hardware. Ultramodern elements base gives you the highest possible power of microphone suppression. Besides, high quality hardware increases reliability of device and extends its operating time. We guarantee trouble-free use of the jammer! "GTG-2020 Voices" will protect you for a long time without breaking which is not the case for many other devices.

100% PROTECTION — not a single spyware with a microphone will be able to "eavesdrop" on your conversation. This reliable protection is possible as a result of using two efficient technologies at the same time: ultrasonic signal + speech-like interference. Any equipment becomes equally useless: laser, wired and wireless microphones, professional dictaphones (such as Soroka, Gnom, E-dic etc.), directional microphones, cellular telephones and etc. "GTG-2020 Voices" will jam any "bug" and won't let anybody learn your secrets.

UNIQUE! Incredibly high suppression power and range! "GTG-2020B Voices" emits a very powerful ultrasonic and acoustic signals (up to 120 dB). It can jam microphones at a distance up to 7 m (23ft). Most analogues, especially of Chinese production, are at least 2-3 times weaker even going by the declared characteristics. Emission power is so high that our specialists recommend to keep transducers away from hearing organs to avoid injury.

NEW! TURBO mode for even more effective suppression when you need absolute confidentiality. TURBO mode activates a special generator which emits ultrasound of a slightly different frequency. Interaction of ultrasonic signals of different frequencies creates frequency beats which raise suppression efficiency without raising emission power. It is a unique development of our specialists! You will not find a similar function in other devices. If you need maximum possible protection against spyware, use acoustic interference together with the TURBO mode and do not worry about anything.​​​​​​​ Note: The only inconvenience in using TURBO mode is that overlapping signals can be heard by a human. That means that when you are not using acoustic interference but TURBO mode is on, you will not be able to use the jammer absolutely secretly. But it will not prevent you from talking, you do not have to strain your voice to speak louder.


Ability to connect speakers to cover larger rooms and/or suppress directional microphones. You can output acoustic interference to external speakers via audio jack located on the front side panel of the device. It will let you protect even very large rooms from eavesdropping. Besides, external speaker makes directional microphones useless.

Operating principle

Device generates ultrasonic signal through 7 transducers. Frequency is determined by a micro-controller and variates according to a specially developed algorithm. Ultrasonic signal affects recording paths of spyware which results in them fixating only indiscriminate noise in which conversation can't be distinguished.

Besides, powerful speaker creates acoustic speech-like interference which destroys the meaning of the conversation: because of it spyware fixates only indiscriminate muttering, restoring the conversation becomes physically impossible. Acoustic interference is generated randomly so it can't be filtered out even on special equipment.

Flexible volume adjustment

Acoustic speech-like interference guarantees the confidentiality of the conversation but has one flaw — unlike ultrasound it can be heard and my be a nuisance in a conversation. Our developers took this into account and developed "GTG-2020 Voices" with an ability to adjust the volume of the acoustic interference. You can always adjust the volume so that device won't muffle your speech and you could speak comfortably. If suppressor is a nuisance, just turn the volume down. Turning the knob to a minimum you will turn the acoustic interference off.

If acoustic interference is turned off, suppressor will be working completely silently (except TURBO mode). One will not pay attention to the working device. If you hide it under the table, for example, there will be no clear evidence that jammer is working.

But without the acoustic interference reliability of protection becomes lower. If you want to be 100% certain that ALL devices with microphones are suppressed, you will have to tolerate small inconvenience.

Using the jammer

Anybody, even a non-professional can use the jammer. All you need to do is point the transducers in a direction of an expected location of recording devices and turn it on. You can adjust the volume level of the acoustic signal if needed. Notice that you can make your protection more reliable by using an additional ultrasonic speakers.

Use the jammer stationarily or portably

"GTG-2020 Voices" can be powered by power supply or by a built-in battery. Its charge will last for a few hours which is a good number for a device of this power. Wherever you go, jammer will always be with you ready to protect you from spying. And you can charge it and use stationarily when you get access to a power supply.

Technical Characteristics

  • Dimensions: 170х95х31 mm (6,7x3,7x1,2 in)
  • Weight: 0,3 kg (10,6 lb)
  • Batteries capacity: Built-in battery 1200 mAh
  • External source of power supply: 12 V, 110/220V network
  • Sound pressure level at 1 m distance from the device, dB: Up to 120
  • Range: optimal — up to 2 m (7 ft); maximal — up to 7 m (23 ft)
  • Jamming method: Ultrasonic interference + acoustic speech-like interference​​​​​​​
  • Charge indication stages: ​​​​​​​4 (green light: lit, flashes once per second, flashes 2 times per second, not lit)

Related Products