HIKVISION DS-2CD6425G1-20

It is a switch of the device audio output. When it is disabled, all the device audio cannot output.
The audio output display varies with the device modes.
4.3.4 Environmental Noise Filter
Set it as OFF or ON. When the  is enabled, the noise in the environment can be  to
some extent.
4.4 Two-way Audio
It is used to realize the two-way audio  between the monitoring center and the target in
the monitoring screen.
Before You Start
●
Make sure the audio input device (pick-up or microphone) and audio output device (speaker)
connected to the device is working properly. Refer to  of audio input and output
devices for device 
●
If the device has built-in microphone and speaker, two-way audio  can be enabled
directly.
Steps
1.
Click Live View.
2.
Click on the toolbar to enable two-way audio  of the camera.
3.
Click
, disable the two-way audio 
4.5 Display 
It  the parameter  to adjust image features.
Go to  → Image → Display  .
4.5.1 Scene Mode
There are several sets of image parameters  for   environments.
Select a scene according to the actual  environment to speed up the display 
Image Adjustment
By  the Brightness, , Contrast and Sharpness, the image can be best displayed.
Network Camera User Manual
17