Adjusting the Volume of a Skype Call
Call Recorder records from the audio input and output devices (microphone and speaker) without any changes to the volume.
To adjust your own microphone volume level, use the input volume adjustments in the "Input" tab of the Mac's System Preferences "Sound" panel.
To adjust the other person's audio level, use the volume slider in Skype's Audio/Video preference panel. If you do not see volume adjustment control, ensure that you have the latest version of Skype. (The control was removed but then added back in Skype v7.33.)
Audio levels can be adjusted after the call using Ecamm Movie Tools.