Administrator’s Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
175
Default
1
Supported
Devices
CP920
Web UI
Settings > Voice > Noise Proof > Noise Suppression
Background Noise Suppression (BNS)
Background noise suppression (BNS) is designed primarily for hands-free operation and reduces background
noise to enhance communication in noisy environments.
Automatic Gain Control (AGC)
Automatic Gain Control (AGC) is applicable to the hands-free operation and is used to keep audio output at nearly
a constant level by adjusting the gain of signals in some circumstances. This increases the effective user-phone
radius and helps with the intelligibility of soft-talkers.
Voice Activity Detection (VAD)
VAD can avoid unnecessary coding or transmission of silence packets in VoIP applications, saving on computation
and network bandwidth.
Topic
VAD Configuration
The following table lists the parameter you can use to configure VAD.
Parameter voice.vad
<y0000000000xx>.cfg
Description It enables or disables the VAD (Voice Activity Detection) feature.
Permitted
Values
0-Disabled
1-Enabled
Default
0
Web UI
Settings > Voice > Echo Cancellation > VAD
Comfort Noise Generation (CNG)
Comfort Noise Generation (CNG) is used to generate background noise for voice communications during periods of
silence in a conversation.
Note
: VAD is used to send CN packets when the phone detects a “silence” period; CNG is used to generate comfortable
noise when the phone receives CN packets from the other side.
Topic
CNG Configuration
The following table lists the parameter you can use to configure CNG.
Parameter voice.cng
<y0000000000xx>.cfg
Description It enables or disables the CNG (Comfortable Noise Generation) feature.
Permitted
Values
0-Disabled
1-Enabled
