EO-3 Audio Acoustic And Ultrasonic Speech Protector

Directional ultrasonic generator with an integrated white acoustic generator – a discreet eavesdropping jammer resembling a common loudspeaker.

Code: U03CZ
$1 769
Category: Speech Protector and Bug Jammers
Dimension: 25 cm / 25 cm / 8 cm
Acoustic noise power: 3 W
The intensity of ultrasound generator: 19 x 120 dB

A directional ultrasonic eavesdropping jammer serves to devaluate any recording and makes interception attempts impossible. It protects you from bugs and other eavesdropping devices:


  • Digital and analogue dictaphones
  • Dictaphones of mobile phones
  • Laser directional interception through windows (remote interception)
  • Built-in and directional microphones
  • Third-party interceptions
  • Stethoscope interception
  • Eavesdropping devices connected to a 220 V network




A directional ultrasonic jammer belongs to the category of discreet devices that serve as a protection against interception. Its design resembles a common loudspeaker which is why it can be placed anywhere in the room without notice.


  • Ultrasound is inaudible to the human ear, so it can be used during any negotiations. The generator is camouflaged as a loudspeaker.
  • The combination of ultrasound and white noise provides a maximum level of protection during negotiations.
  • It devaluates any recordings made by analogue or digital dictaphone, cell phone or installed eavesdropping device.

See the video of the generator in practice, in the background of sound recording.



An ultrasonic jammer combines the advantages of jamming interception using ultrasound and white noise, secures conversations in the room, in a café or in a car. Any cell phone, placed on the table or hidden in a pocket, could be used to record any conversation, as a well as a hidden eavesdropping device in the room.


The jammer generates ultrasonic and sonic interferences and this way precludes eavesdropping. Ultrasonic transmitter precludes interception even by the best microphones used for listening. In combination with the white noise generator it serves as a perfect eavesdropping jammer and eliminates analogue recording devices. This synergy of 2+1 devices in one provides safety and security to the participants of the conversation and ensures protection of information.


Main characteristics


  • Ultrasonic jamming of interception: 19 ultrasonic generators with an intensity of 120 dB create a strong sonic barrier for microphones of all modern phones (incl. iPhone, Samsung and others) as well as for all modern dictaphones and eavesdropping devices.


  • Acoustic suppression of interception: high-quality and low noise acoustic loudspeaker with a maximum performance of 3 W is able to easily jam analogue microphones of phones and all obsolete voice recorders and microphones in range. The extent of suppression depends on the size of the room and the distance from the participants. It is controlled by adjusting the volume - using the handle on the front panel of the device.


Instructions for use


Place the jammer approximately in the direction of possible interception. Set up the volume of acoustic noise to your preferences, so it wouldn’t disturb the conversation in the room. Then turn on the jammer with a remote control to one of the following modes:


  1. Quiet ultrasound – suppresses all high-quality voice recorders.
  2. Device off – protection is off.
  3. Ultrasound + quiet acoustic noise – the main operating mode in which you can negotiate comfortably and be protected against all types of listening devices at the same time.
  4. Ultrasound + loud acoustic noise – the maximum protection mode used when you need to fully protect information at the cost of reducing negotiating comfort.



Technical parameters


An ultrasonic generator can work in two modes:


  • Ultrasonic generator with an intensity of 19 x 120 dB
  • 3 W white noise generator
  • Device size: 25 cm/25 cm/8 cm
  • Both modes can be combined


Alternative products


This device isn’t the right one? We have other offers of eavesdropping jammers for you:



Professional detection of interception

Do you have a suspicion that there is a listening device in your office, car or household? Contact us – we specialize in eavesdropping detection services, elimination of interception and installation of permanent protection against interception.


We deliver this device worldwide using DHL EXPRESS. Delivery time is 2-4 business days worldwide.

The goods are developed, manufactured and shipped from the Czech Republic.

For an offer on larger quantities or the complete solution please countact us:

e-mail: office@eo-security.com

tel: +420 774 429 006 (WhatsApp, Viber, Telegram, Signal)