For a recent project I needed to record audio of a speaker over the phone, and wanted to record using Skype. This isn't as easy as one would think. For Windows users, apparently you can do this through Audacity, plain and simple. For Mac users, we aren't so lucky as I found out. You can watch a video here that does an okay job explaining what to do: http://www.youtube.com/watch?v=nqfog_Ve5Rc Or, since I needed to outline it for myself, you can read below for the basics for recording WITHOUT an external microphone, and without recording YOUR vocals:
What you'll need besides Skype: 1. Garageband. This big application is a resource hog. Your computer will start to heat up. Oh well. 2. LineIn. A free application from Rogue Amoeba that allows you to "play input through output device" which apparently you used to be able to do on Mac OS 9- http://www.rogueamoeba.com/freebies/ 3. Soundflower. Another free application that allows applications (like Garageband or LineIn) to pass audio to other applications (like Garageband or LineIn). http://cycling74.com/products/soundflower/ How to set it up using no external microphone or speakers: 1. Open system preferences, under Sound, choose Input of "Line In - Built in Input" 2. Open system preferences, under Sound, choose Output of "Internal Speakers - Built-in Output" 3. Open SoundFlower. It'll appear as an icon up by your clock, power indicater icon, etc. Click it and make sure it is checkmarked on Soundflower (2 ch) "Built-in Output" 4. Open Garageband. Select "Vocal" if you have to for a new project. Keep the settings they give you for that file. Under preferences, change Audio Input to "Soundflower (2ch)" and change Audio Output to "Built-in Output" 5. In Garageband, in the lower right, put Monitor to "Off" unless you want feedback. You'll still be able to hear the caller, but not yourself. The caller will hear you. Garageband will not record your vocals. 6. Open LineIn. Make sure you have selected Input from "Built-in Input: Line In" and Output to "Soundflower (2ch)." Now click Pass Thru. 7. Open Skype and place your call. 8. Go back to Garageband and press Record. 9. After recording, if you want to "export" an uncompressed file from Garageband, you have to "Share With Itunes" and make sure to select as an AIFF. All of this for what should be a relatively simple process to record and save an uncompressed audio file of an IP based phone call.
Lastly, check out this tutorial on using Skype for interviews: