There is a problem on EnglishCentral that PC users with Windows 7 and IE 7 or Firefox browsers may experience: the volume when recording goes very low on videos.
It is frustrating but after recording a line, suddenly the volume will become very low. It is actually a problem with Windows 7 and its audio controls reacting to soften volume when needed. They have yet to release a fix but here is what you should do if you experience this problem. It’s easy to do and you’ll be back to normal and using EnglishCentral like a pro – right away!
source: http://www.ehow.com/how_5820564_fix-windows-low-volume-problem.html
