I have several sound input and output hardware options on my current Mac system: the internal hardware, Logitech Webcam C930e and Monoprice Bluetooth headphones. To switch among these input and output sources, I used to repeatedly open the Sound preference pane in System Preferences and then select my desired choice:

Mac OS X Sound System Preference


 A much faster method

Sound icon in menu barBy default, the OS X menu bar sound icon allows you to adjust the system output sound volume. But if you hold down the option key before clicking the menu bar sound icon, it reveals all your options for both sound output and input. Simply select the option you want without ever opening your System Preferences.