User Guide

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8.10. Phone->Audio
Echo Canceller: Echo Canceller: To remove acoustic echo from a voice
communication in order to improve the voice quality .
Mic Volume: To adjust the handset mic volume.
VAD(Voice Activity Detection): Allow IP phone to detect the presence
or absence of human speech during a call. When detecting period of
―silence‖, VAD replaces that silence efficiently with special packets that
indicate silence is occurring. It can facilitate speech processing, and
deactivate some processes during non-speech section of an audio
session. It can avoid unnecessary coding or transmission of silence
packets in VoIP applications, saving on computation and network
bandwidth.
CNG(Comfort Noise Generation): Allow IP phone to generate
comfortable background noise for voice communications during periods
of silence in a conversation. It is a part of the silence suppression or VAD
handling for VoIP technology. CNG, in conjunction with VAD algorithms,
quickly responds when periods of silence occur and inserts artificial