Skype has a feature called Automatic Gain Control which it uses to try to improve the audio quality of your call. When skype thinks your sound levels are not right it starts messing with your volume controls behind your back. Most of the time this works fine but not always. And when it gets things wrong you have a problem. There is no way to turn this feature off anymore! It used to be an option in older versions of Skype but not anymore. To be honest that’s a pretty retarded thing for the Skype people to do. Myself and Allison Sheridan ran into this problem when we tried to record our weekly ‘chit chat across the pond’ segment for the NosillaCast podcast over skype. No matter what Allison did her levels always dropped too low. She’d put them just right and then within 20 seconds they’d be all wrong again. Took us a while to figure out what was causing this, but in the end we figured out that it was Skype’s Automatic Gain Control ‘feature’. It took a lot of Googling but Allison found the right answer in the end.

[tags]Skype, Automatic Gain Control[/tags]

To fix this problem you have to edit a file called shared.xml which in OS X you’ll find in the Library/Application Support/Skype folder in your home folder. I have no idea where Skype hides this file on Windows so if you’re on Windows you’ll have to do a search. You need to open this file with a text editor (NOT a word processor, something that can read and edit plain text) and find the section starting with <VoiceEng>. Straight after that line you need to insert the following line:

<AGC>0</AGC>

BTW, if you wish to also disable echo cancelation you could do so by adding the following line in the same place:

<EC>0</EC>

Then just save this file. You should make this edit while Skype is not running.