I can't communicate with other devices

Make sure that all terminals are operating on the same frequency channel (or group). Then, make sure that only one of the terminals has the role M1 (or identified by the number 01) and that they all have the network icon. Also check that your headset is properly connected to the terminal. 

One or more devices cannot connect to an audio conference

  • Check the connection of your headset.
  • Validate that the terminals are on the same frequency channel as the terminal with role M1. 
  • Make sure that the configuration (with fixed key encryption) has been carried out on each of the terminals in order to be able to take part in the conference, especially if you have added a terminal since the beginning of the conference. 

Communication is disrupted (cuts, hatching, sizzling)

  • Check your configuration and adjust the placement of your microphone in front of your mouth. 
  • Change the frequency to avoid possible disturbances. 
  • Make sure that 2 terminals with the Master role are not switched on at the same time (restart the configuration or switch off one of them if this is the case). 
  • The microphone of one of the terminals may be damaged. Replace it.
  • Another communication system other than VOKKERO must be operating near yours. Change the frequency channel to avoid interference.

I can hear myself talking, there is an echo

  • Check that the microphones of the different terminals are a few metres away from each other. 
  • On GUARDIAN, check that your microphone icon displays the letter "A", otherwise contact our technical support department. 

Noises come into the microphone

Omnidirectional and electret microphones are more sensitive and can let through loud noises such as chainsaws...  

What is the role of the M1 Master?

  • The terminal on slot n°1 of the configurator-charger is the Master ("M1" for GUARDIAN).
  • The role of the Master is very important because it sends a frame (beacon) to the other terminals to synchronise them in time and ensure that everyone can send and receive in the same conference.


  • If no Master on = no audio conference possible
  • Never keep 2 Master products switched on at the same time.
  • Ideally, the Master should have a rather central place respectively to the other users.

Why do I have latency?

Communication latency is due to 3 components:

  1. The integration of signal processing (Voice Activity Detector)
  2. The encoding of audio in radio / decoding without a base station.
  3. The radio protocol (cycle times)

The device does not switch on

Check that the battery is charged.

What is VAD?

VAD = Voice Activity Detector.

Its sensitivity can be adjusted in the configurator menu (Voice Gate Preset menu in GUARDIAN or Voice Detector in GUARDIAN SHOW).

Can the VAD be removed?

No, but the Whisper Mode makes detection more sensitive.

Only the GUARDIAN SHOW product designed for the entertainment world allows deactivation of the VAD under certain conditions.

What is the patented noise filtering?

The noise filter is an additional features in the audio signal processing. The VAD detects voice, while the filter attenuates non-speech components of the signal.

Microphone Gain Controller: regardless of the type of headset used, signal processing normalises the microphone volume, which allows each user to hear their colleagues at the same volume.

What radio modulation is used?

The modulation used is GFSK, Gaussian Frequency Shift Keying.

Which radio bands are used?  

The ISM bands (Industrial, Scientific and Medical).

How many frequencies are available and to what power?

10 frequencies are available with powers varying between 10 and 500 mW according to European regulations (refer to the table in the user manual).

What is the radio bandwidth?

~ 200 KHz

What is the maximum number of users?


Is there an impact by using the group mode?

The range may be slightly shorter.

Can 2 systems be used in parallel on the same frequency without interference if they have been configured with 2 different encryption keys?

No. The operators of the two groups will not get along thanks to the different encryption keys, but the systems will still interfere with each other (audio cuts, interference, etc.).

What is the audio sampling frequency?

  • GUARDIAN PLUS, STAFF, ATEX, ELITE: 16Khz (8Khz bandwidth) = like voice over IP
  • GUARDIAN STANDARD: 8Khz (4 Khz bandwidth) = like traditional telephony