User Manual
Network Video Recorder User Manual   
UM NVR v4.xx 111717NA  136 
1)  Select the Exception Detection tab. 
2)  Check the Audio Loss Exception, Sudden Increase of Sound Intensity Detection, 
and/or Sudden Decrease of Sound Intensity Detection checkbox(es). 
Audio Loss Exception: Detects a steep sound rise in the surveillance scene. You can set 
the detection sensitivity and threshold for steep sound rise by configuring its Sensitivity 
and Sound Intensity Threshold. 
-  Sensitivity: The smaller the value, the more severe the change must be to trigger the 
detection. Range [1-100]. 
-  Sound Intensity Threshold: It can filter the sound in the environment. The louder the 
environment sound, the higher the value should be. Adjust it according to the 
environment. Range [1-100]. 
Sudden Decrease of Sound Intensity Detection: Detects a steep sound drop in the 
surveillance scene. You need set the detection sensitivity [1-100]. 
Step 6 Set the arming schedule. Refer to Chapter 12.1 Configuring Arming Schedule.     
Step 7 Set the linkage actions. Refer to Chapter 12.2 Configuring Alarm Linkage Actions. 
Step 8 Click Apply. 
13.10 Sudden Scene Change Detection 
Purpose 
Scene change detection detects the change of the surveillance environment affected by 
external factors such as intentional rotation of the camera. 
Step 1 Go to System > Event > Smart Event. 
Step 2 Click Sudden Scene Change. 










