Microphone jammer "BugHunter DAudio bda-3 Voices" with 7 ultrasonic transducers, an improved jamming system and an option to connect additional external ultrasonic speakers. 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 up to 7 meters (23 ft) and at an even greater range when used with external ultrasonic speakers. For maximum 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 110/220V power supply unit or built-in battery.
"BugHunter DAudio bda-3 Voices" is a highly effective microphone jammer
"BugHunter DAudio bda-3 Voices" is an upgraded model that retains all of the advantages of its predecessor — interference system got improved, two additional ultrasonic transducers and a jack for external ultrasonic speakers were added.
"BugHunter DAudio bda-3 Voices" blocks any microphones in the range of 7 meters
"BugHunter DAudio bda-3 Voices" blocks any microphones in the range of up to 7 meters (23 feet)
Key differences from the old model:
New jamming system. "BugHunter DAudio bda-3 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 the side, it has two additional transducers located on the top panel of the device. By emitting ultrasound upward, these two transducers create a "virtual wall" that protects from any microphones or dictaphones located behind it.
Device is equipped with seven ultrasonic transducers. Two are located on the  top and five on the side 
The device is equipped with seven ultrasonic transducers. Two are located on the top and five on the side
Option to connect additional ultrasonic speakers. In comparison to "BugHunter DAudio bda-2 Voices" that supported only acoustic speakers to amplify the acoustic interference, the new model supports connection of ultrasonic speakers via mini-jack cable. Operating with an additional speaker "BugHunter DAudio bda-3 Voices" efficiently suppresses even hidden microphones, which are located outside of the range of seven main transducers. For maximum efficiency the 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. Up to 4 external ultrasonic speakers can be connected to one device.
Example of combined usage of a jammer with two speakers (one speaker is  located on the wall and the other one is under the table)
Example of combined usage of BDA-3 with two speakers (one speaker is located on the wall and the other one is under the table)
Important: Ultrasonic speaker is not supplied with the jammer and is sold separately. If required, you can attach two speakers via a common splitter for a 3.5 mm jack (shown on the picture below).
This simple adapter lets you connect two ultrasonic speakers to the jammer
This simple adapter lets you connect up to four ultrasonic speakers to one device
Other advantages of "BugHunter DAudio bda-3 Voices":
Acoustic speech-like interference guarantees 100% confidentiality. In addition to ultrasound, this 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. Modern component base offers the highest possible power of microphone suppression. Besides, high quality hardware increases reliability and extends operating time. We guarantee trouble-free use of the jammer! "BugHunter DAudio bda-3 Voices" will protect you for a long time without breaking which is not the case for many other devices.
100% PROTECTION — no 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 + white noise interference. Any spy equipment becomes useless: laser, wired and wireless microphones, professional dictaphones (such as Soroka, Gnom, E-dic etc.), directional microphones, cellular phones etc. "BugHunter DAudio bda-3 Voices" will jam any spy bug and help you protect your secrets.
UNIQUE! Incredibly high suppression power and range! "BugHunter DAudio bda-3 Voices" emits a very powerful ultrasonic and acoustic signals (up to 120 dB). It can jam microphones at a distance of up to 7 m (23 ft). Most competition, especially of Chinese origin, are at least 2-3 times weaker even by the declared characteristics. Emission power is so high that our specialists recommend to keep transducers away from hearing organs to avoid injury.
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 of 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 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, the use of external speakers allows to withstand recording by directional microphones.
Capability to connect one or two additional ultrasonic speakers makes "BugHunter DAudio bda-3 Voices" even more effective in protecting oneself from audio espionage (Attention! Package doesn't include the additional speaker. It is sold separately)
Capability to connect one or two additional ultrasonic speakers makes "BugHunter DAudio bda-3 Voices" even more effective in protecting oneself from audio espionage (Attention! Additional ultrasonic speakers are sold separately).
Operating principle
Device generates ultrasonic signal through 7 transducers. Frequency is determined by a micro-controller and varies 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, a powerful speaker creates acoustic white noise interference which destroys the meaning of the conversation - 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 specialized professional equipment.
Flexible volume adjustment
Acoustic white noise interference guarantees the confidentiality of the conversation but has one disadvantage — unlike ultrasound it is audible and may cause discomfort during the conversation. Our engineers took this into consideration and developed "BugHunter DAudio bda-3 Voices" with a capability to adjust the volume of the acoustic interference. If the suppressor is a nuisance, just turn the volume down. By turning the knob to the minimum, you