Bloodhound-Detect Audio Attacks « Spectral Guard

By: Spectral Guard  09-12-2011

Bloodhound-Detect Audio Attacks « Spectral Guard

Traditionally, the TSCM professional uses a variety of tools, including a portable oscilloscope, precision multi-meter, and specialized multi-function cable meters, time-domain reflectometers and clip-on audio amplifiers to test each line in a facility for the presence of audio, a mic or a line tap – a time consuming and complex approach to finding room audio. The traditional complicated equipment training  is in excess of one week!

The ShearwaterDigital Bloodhound, designed using electro-magnetic principals, incorporates an ASMD - Acoustically Stimulated Microphone Detector for detecting audio eavesdropping. This revolutionary and highly specialized tool, developed by the designers while in Government service, and updated with highly selective DSP technology last year, is fully portable and easy to learn. We can teach a typical student to use the Bloodhound and become an effective ‘mic and wire sweeper’ in less than a day!

Bloodhound operates by detecting the very tiny electromagnetic spatial field created when an audio signal from a microphone is generated. Bloodhound uses a special and proprietary field probe unit with high amplification and incorporates elaborate digital filtering algorithms and high speed DSP technology to remove extraneous power line noise frequencies so that only the audio on the compromised line is detected. 

The Bloodhound has two modes: Active and Passive.

In the more covert Passive mode, when one doesn’t want to alert the attacker’s ‘listening post’ the operator simply tests all areas of the room under investigation for the presence of audio. Generally, we find that the sensitive Bloodhound digital probe only needs to be within a foot or so of the mic, or it’s associated conducting cable, in order to pick up room audio.  Of course, the Bloodhound’s comprehensive kit of components provides the tools to generate common everyday sounds, typical of any environment, so the attacker won’t know you are there. With Bloodhound there is no more time-consuming and often dangerous probing of  telephone wires, CAT 5 cables, power lines.  

In the Active mode, the operator can use the advanced digital probe and associated high gain audio amplifier to induce acoustic feedback to easily detect microphones.  The characteristic acoustic howl cannot be mistaken!

With a combined usage of the Active and Passive mode, Digital Bloodhound detects: 

  • Amplified wired microphone attack system where the target site is wired directly to a listening post.
  • Audio attack on telephone instruments.
  • Audio presence on cables of all types and varieties.
  • Radio Microphones – audio component.
  • Tape recorder attacks (many types).
  • Video camera surveillance (many types). 
  • Carrier current microphones.

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Services « Spectral Guard

Our sweep team is equipped with the latest commercial test instruments and proprietary TSCM equipment designed to detect and analyze signals with precise measurements to enable detection and response to technical attacks. Spectral Guard conducts technical surveillance countermeasures sweeps and evaluations for private and government facilities.