Obviously mobile phones have an infinite number of benefits for communication and business; however, they also create certain threats of information leakage. One of the potential leakage channels is the phone’s microphone being able to pick up surrounding acoustics with a high sensitivity. The PHONE SAFE ULTRA has been developed by information security professionals to protect against this exact type of threat.

While developing this product the following features and vulnerabilities of modern phones were taken into account:

  • The phone can be intentionally, or covertly, ‘off-hook’ during important negotiations
  • Voice recording software can intentionally , or secretly, run on the smartphone
  • Listening software can run in a ‘stealth’ mode Spyware can be installed on the smartphone without the owner’s knowledge, allowing attackers to activate covert eavesdropping around the phone. There are known cases of transmission of such software by exploiting the vulnerabilities of some messengers
  • The acoustic environment around the phone can be transmitted to the server , or cloud service of the attackers either in real time or with a postponed uploading
  • Smartphone apps which have access to the phone’s microphone can be used for eavesdropping in cases of them having been hacked (usually messengers or social network apps)
  • Uploading of information can be done in the following ways: conventional voice call, mobile internet, Wi-Fi, Bluetooth, the phone’s connector


  • Blocks the microphone of the phone with the help of non-filterable ultrasonic interference
  • Efficiently prevents surround recording apps from capturing conversations and sounds
  • The frequency of interference has been optimally selected for the best performance and affects all existing models of smartphones
  • Made with the design of an attractive natural wood stand
  • The acoustically isolated phone can remain close to the owner where the screen can be easily observed
  • The phone stays online and available for incoming calls
  • No illegal radio jamming
  • Can be powered by the external USB, or from the built-in rechargeable battery
  • Has 2 sensors, increasing the battery’s resource: the device starts producing interference when a phone is inserted (IN USE sensor) and a conversation is present (ACTIVITY sensor)
  • The rechargeable battery provides a continuous working time of 6 hours if the USB source is unavailable
  • Is compatible with all types of phones (max. width 88 mm)


  • Type of interference: Ultra sound
  • Frequency: 20 kHz
  • Power of noise: <2W in the active area
  • Guaranteed suppression area: 10 cm from the transducer
  • Dimensions: 114x105x79 mm
  • Compatible phones: Width up to 88 mm
  • Weight: 0.5 kg
  • Power:
    • USB 5V
    • Built-in rechargeable battery
  • Current consumption:
    • 500 mA (noise mode)
    • 5 mA (stand-by mode)
  • Battery: Li-Ion, 3.2 V, 3200 mAh
  • Connector: USB Type C
  • Battery resource: >6 hours
  • Recharging time: 6 hours
  • Sensors: IN USE , ACTIVE


  1. 1. PHONE SAFE ULTRA device
  2. 2. USB Type C cable
  3. 3. Transparent cover
  4. 4. User manual