If you haven't downloaded Audacity yet, do so now (http://audacity.sourceforge.net/
). Of course, if you have any other preferred software, you can use that as well. However, I'll be assuming that you're using Audacity for this instructable. Go ahead and install Audacity, the default options will do fine. Once installed, go ahead and run it. You might have to configure which input your computer should capture sound from, do this by going to Edit > Preferences and selecting "Line-In" under the Recording section. Also, you should enable "Show Clipping" by going to View > Show Clipping.