So you can use the volume bar in the menu under Mac OS X
- You can open the necessary settings in your Mac OS X by tapping on the Apple Icon and "system preferences..." to choose.
- Click on "sound".
- You put the check mark in the Option "show volume in menu bar".
- You want to have the volume control in the menu bar, remove the check mark again.

Mac OS: volume control
The Declaration refers to Mac OS X 10.9.3. Other versions might slightly differ. In a further article to read you, as you Skype for Mac to turn the sound off.
