This file is an extension to my 'Linux on Laptop' web site, although it is not strictly a linux problem (Windows and Mac users also appear on web sites discussing Skype echo problems) nor a laptop problem.
It seems that many people have problems with audio echo when attempting to use Skype. This can have various causes and various cures. See http://www.skype.com/help/guides/soundsetup.html However the linux link from that page does not have the important information I found elsewhere (at least it did not when I looked on 3 Nov 2007).
The most obvious cause of echo is a microphone picking up the sounds coming from a nearby speaker. This should not occur if you are using a headset. Other causes can be transmission problems on the internet.
The problem I had was that I could use the skype test call service and everything seemed fine. Other people I called said they had no problem communicating with other skype users, though when talking to me they kept hearing their own echo, and I found their sound levels going up and down making it difficult to hear what they were saying.
It was clear from all the facts that the problem had something to do with my audio settings. However when I ran alsamixer, kmix or gnome-volume-control I could not find anything that looked wrong.
Eventually I found the solution here:
http://forum.skype.com/index.php?showtopic=23373
The version of the solution for windows was:
1. Download the latest version of the realtek driver (important)
2. double click on the windows speaker icon
3. select playback properties
4. MUTE the microphone in the playback section
5. select recording properties
6. SELECT the microphone in the recording section
So I translated that for my situation, as follows:
1. run alsamixer
2. set it to show playback
3. turn off mic
4. set it to show capture
5. turn on mic
After that when I tried talking to a colleague the echo problem had
gone. I hope this information is useful to others. I suspect the
alterations can also be made using kmix or gnome-volume-control but
have not checked.
Maintained by
Aaron Sloman
School of Computer Science
The University of Birmingham