PulseAudio is the new sound server that’s being included in Ubuntu 8.04 and other recent Linux distros. A sound server lets changes be made to sound between the applications and sound hardware layers. Among other features, PulseAudio provides per-application volume controls, a plugin architecture, low-latency, networking features, and good application compatibility.
PulseAudio can do a lot, but one great feature is the ability to adjust the volume of individual applications. This is great for applications such as Flash applets that usually don’t let you adjust volume.
Ubuntu 8.04 is not currently including a user interface for this feature, but it’s easy to install one. Install the package pavucontrol from your package manager or by using the command below:
sudo apt-get install pavucontrol
Run pavucontrol in a terminal to start the PulseAudio Volume Control. (You’ll probably want to add an application menu item through System->Preferences->Main Menu.)
As new applications that use sound are launched, they will instantly appear in the window. You can adjust the volume sliders for each application and the sound output will also change instantly, different channels can even be adjusted separately. In the other tabs, you can adjust the volume for entire input and output devices just like applications.
PulseAudio will remember your volume settings when you reopen applications, so don’t forget to change the volumes back to 100%.