Voice Activity Detection (VAD)

Voice Activity Detection (VAD) or Sound Detection is a feature available for the IP Station range. Voice Activity Detection samples the peak amplitude detected at the microphone every 30 ms and converts it to dB. If the sampled amplitude is continously above a trigger amplitude for a set duration, then a DAK key is triggered.

The VAD feature is available only when the station operates in ICX-AlphaCom mode.

User interface

The Voice Activity Detection configuration is done from the IP-station web interface at:

• Advanced ICX-Alphacom --> VAD for INCA Stations
• Advanced ICX-Alphacom --> Sound Detection for Turbine Stations

The following settings are possible to configure:

Sound Detection configuration page in IP Stations

• Sound Detection status: Enable or Disable the feature
  • In Turbine v. 4.7 the options are expanded:
    • Disable
    • Enable (Disable When Audio Out) - The Sound Detection is disabled when the loudspeaker is playing audio, to prevent the station from triggering by its own audio
    • Enable Always) - The Sound Detection is active also while playing audio. Can be used on devices without speaker (e.g. TKIE kit acting as mobile radio interface)
• Minimum amplitude (dBA): Choose the trigger amplitude
• Minimum duration of audio (ms): Choose for how long the sampled amplitude must be above the "Trigger ampltiude" before triggering the DAK key
• DAK key to activate: Choose which DAK key to trigger. The station will simulate that this DAK key is pressed.
• Minimum time before reactivation (ms): Choose how long to wait before enabling VAD after triggering the DAK key
• Report DAK key off after (ms): This parameter sets the duration of the DAK key press.

Notes on operation

• The sound pressure SPL is dropping by 6 dB (four times) for every doubling of the distance from the microphone.
• The audio detection is before the noise reduction circuit, so in case Noise Reduction is activated, noise will always cause the detector to trigger.
• The VAD is working only when the station is in idle. It will not work if the Station is for example in conversation or in conference.
  • Turbine devices with firmware 4.7 or later can also trigger during converation or while in conference.
• The VAD feature is only available when the station is used in ICX-AlphaCom mode. The feature is not available in Pulse or SIP mode.

Software requirement

• INCA Station software 01.09.3.0 or later.
• Turbine: available in all versions

Related articles

• Scream Alarm using VAD