 - In Voice over IP (VoIP), voice activation
detection (VAD) is a software application that allows a data network carrying
voice traffic over the Internet to detect the absence of audio and conserve
bandwidth by preventing the transmission of "silent packets" over the
network. Most conversations include about 50% silence; VAD (also called
"silence suppression") can be enabled to monitor signals for voice activity
so that when silence is detected for a specified amount of time, the
application informs the Packet Voice Protocol and prevents the encoder
output from being transported across the network.
Voice activation detection can also be used to forward idle noise characteristics
(sometimes called ambient or comfort noise) to a remote IP telephone or gateway.
The universal standard for digitized voice, 64 Kbps, is a constant bit
rate whether the speaker is actively speaking, is pausing between
thoughts, or is totally silent. Without idle noise giving the illusion
of a constant transmission stream during silence suppression, the listener
would be likely to think the line had gone dead.
| LAST UPDATED: |
06 Mar 2008
|
 |
Do you have something to add to this definition? Let us know.
Send your comments to techterms@whatis.com
|
|
More resources from around the web:
|
|
