I often stumple upon users who have problems playing audio. A common problem is that Adobe Flash (or another application) doesn’t play any sound even though other programs like Totem, Rhythmbox etc. work fine.
Usually those people have more than one sound device in their system. E.g. a internal sound card, a USB webcam with microphone and a USB headset. The problem is that that those users have more than one “sink” where applications can send their audio output to. Eventually you listen to music over your usb headset, muted your internal sound card and use a application which uses your internal soundcard as sink. The result: No sound with certain applications…
The solution for those issues is pretty simple, but you have to install a couple of tools to be able to manage PulseAudio. The first one is PulseAudio Volume Control.
$ sudo apt-get install pavucontrol
After the installation you can start the program via “Applications -> Sound&Video -> PulseAudio Volume Control” (Eventuell you’ll have to activate this menu entry first by opening alacarte) . Inside the Tab Output Devices you’ll find every sink of your system which is able to output sounds. In my case this is a internal sound card and a usb card.
The second important tab is Playback. Every program which currently plays audio will appear here. With the adjacent buttons and sliders you can manipulate every single stream. You can mute individual applications, you can reduce the volume of e.g. Pidgin so that you won’t get a heart attack when you watch a movie and someone writes you a message etc…
Finally you’ll find here also a way to direct the stream of every single application to a different audio sink. E.g. you can redirect the sound of Ekiga to your USB headset while totem uses your internal soundcard which is connected to a decent set of speakers.
This is also the solution to your problem. Check here if your “muted” application uses the right sink! All in all you gain a lot of flexibility with PulseAudio. You can choose for every single application how loud it should be able to play audio and which device it should use.
And additionally: You are not limited to a single computer! A couple of days before I blogged about Avahi and it’s possibilities possibilities (Sorry: Only in German available , i didn’t translate this article yet), PulseAudio uses Avahi to find other PA servers inside your LAN. This way it is possible to redirect e.g. the output of a media player on your netbook to a server which is connected to a decent music center. To be able to do this you have to install the program PulseAudio Preferences via
$ sudo apt-get install paprefs
After this you can start this tool “System -> Settings-> PulseAudio Preferences”. Here you can enable that your PA server discovers other PA servers inside your LAN or even allow other computers to connect to your PulseAudio server.
If you set your PA server to search for other PA sessions inside your LAN you can redirect the output of applications to other PA servers the way I explained before.