The playback tab of pulseaudio volume control gives you the ability to the control the output device, mute, or change the volume of each application. To change the Volume of each application on the playback slide the slider to the right for more volume or to the left for less volume. The button with an X over the speaker is a mute button and if it is a darker gray that application is currently muted and can't make any sound. The drop down menu has next to the word on shows the output source.
To launch pulse audio volume Control from the menu -> Sound and video -> Pulse Audio Volume control or run pavucontrol-qt from the command line. Another way to launch Pulse audoio volume control is to click on the volume applet in the panel and click the mixer button.
