D-Link DCS-6010L User Manual page 52

Section 4: Configuration
Fixed quality: Select the image quality level for the camera to try to
maintain. High quality levels will result in increased bit
rates.
Encoding Choose between G.726 or G.711
Audio in off: Selecting this checkbox will mute incoming audio.
Audio in gain level: This setting controls the amount of gain applied to
incoming audio to increase its volume.
Audio out off: Selecting this checkbox will mute outgoing audio.
Audio out volume level: This setting controls the amount of gain applied to
outgoing audio to increase its volume.
D-Link DCS-6010L User Manual 52