Scream Alarm

From Zenitel Wiki


This article describes how to use the in-built Sound Detection (Voice Activity Detection - VAD) in the Zenitel IP stations as a Voice Alarm. This application can typically be used at:

  • Nursery home
  • Old peoples House
  • Correctional facilities
  • Mental Hospitals
Scream baby.png
Scream Alarm

The configuration is best illustrated by an example, and this article describes a nursery. A number of Nursery stations can detect when babies are crying, and a number of Staff stations will receive a visual (text) message and audible signal when this is detected. The Nursery stations have their inbuilt Sound Detection enabled, and the Staff stations can switch the function on/off by pressing a button (a DAK key dialing 9534). In case of a IP Flush Master station, a red LED in the DAK key will indicate when the Voice Alarm is active.

See also Silent Alarm


DAK1 on the Staff stations is programmed with the standard event trigger 9534 (feature 52, Event Trigger - Without Tone). The programmed event toggles a UDD, and also switches the red LED in the same DAK on/off. All IP stations have the VAD function inbuilt in their software. In this application the VAD is enabled on all Nursery stations. When the station microphone picks up sound according to the settings in VAD, it will trigger DAK5. In the ICX-AlphaCom Event Handler there is an Station Input or Station DAK key event programmed to check a UDD before sending a mail to the Staff stations. If the UDD is off, no mail is sent. But if the UDD is on, then the Staff stations will recieve a mail message saying that there is Voice Alarm activated at that particular station. The message is sent to a group, and by using the group delete flag the mail is removed from the other Staff stations when one of them deletes it.


  • Staff stations are put in UDP group 1 - "Staff"
  • Nursery stations are put in UDP group 2 - "Nursery"
Scream Al UDP.PNG
UDP Group membership

  • Staff stations are members of group 7 - 891 Staff group
Scream Al Grp.PNG
Staff Group membership

Event Handler programming

Create the events below, and copy/paste the action commands into your Event Handler.

Event 1 - Toggle "Sound Detection" on/off

A "Staff" station can enable or disable the Sound Detection by dialing the code 9534. It might be that the feature should be turned off during daytime, and turned on during nighttime. When dialing the code, the display will show current status, e.g. "Alarm is ON". If the number 9534 is configured on a DAK key with LED's, the red LED will turn on when sound detection is enabled. Information will be sent to the System log whenever a staff station enable or disable the Sound Detection.

Toggle Sound Detection flag on/off

Action commands:

IF %udd(600)
WUDD 600 0
IND %1.phy %1.dak(I%2.dir) 1 1 OFF
$DTS L%1.dir 'Alarm is OFF' U1
LOG "Alarm disabled by %1.dir %1.nam"
WUDD 600 1
IND %1.phy %1.dak(I%2.dir) 1 1 ON
$DTS L%1.dir 'Alarm is ON' U1
LOG "Alarm enabled by %1.dir %1.nam"

Event 2 - Sound Detection event

This event will be triggered when Sound Detection notification is sent from a Nursery station. If Sound Detection is enabled (UDD 600 = 1), a text message like "Alrm: Nursery 3" will be sent to all stations in group 891, and information wioll be sent to the System log.

Send text message when Scream Alarm is triggered

Action commands:

IF %udd(600)
$STM L%1.dir L891 U145 'Alrm: %1.nam' U6
LOG "Voice Alarm detected from %1.dir %1.nam"

Enabling the Sound Detection (VAD)

  1. Log on to the IP station that should monitor sound.
  2. Navigate to Advanced ICX-AlphaCom > Sound Detection, and set "Sound Detection status" = Enabled (Disabled when Audio Out).
  3. It is also possible to change the audio level, duration before activation, and the DAK key to activate when audio is detected (default is DAK 5).


Related articles