aec stuff

git-svn-id: http://svn.xiph.org/trunk/speex@12811 0101bb08-14d6-0310-b084-bc0e0c8e3800

1 files changed, 26 insertions, 0 deletions

diff --git a/doc/manual.lyx b/doc/manual.lyx
index da2550e..f5e3429 100644
--- a/doc/manual.lyx
+++ b/doc/manual.lyx
@@ -604,6 +604,27 @@ Acoustic Echo Canceller
 \end_layout
 
 \begin_layout Standard
+In any hands-free communication system (Fig.
+ 
+\begin_inset LatexCommand \ref{fig:Acoustic-echo-model}
+
+\end_inset
+
+), speech from the remote end is played in the local loudspeaker, propagates
+ in the room and is captured by the microphone.
+ If the audio captured from the microphone is sent directly to the remote
+ end, then the remove user hears an echo of his voice.
+ An acoustic echo canceller is designed to remove the acoustic echo before
+ it is sent to the remote end.
+ It is important to understand that the echo canceller is meant to improve
+ the quality on the 
+\series bold
+remote
+\series default
+ end.
+\end_layout
+
+\begin_layout Standard
 \begin_inset Float figure
 wide false
 sideways false
@@ -647,6 +668,11 @@ end{center}
 
 \begin_layout Caption
 Acoustic echo model
+\begin_inset LatexCommand \label{fig:Acoustic-echo-model}
+
+\end_inset
+
+
 \end_layout
 
 \end_inset