I have an bluetooth headset connected to my computer, the buttons play/pause/volume are working fine, but i have no sound in the headset, but in the speaker of the computer. In fact i played with the sound settings of my headset in the sound settings of ubuntu, and after choosing "switch off", the headset did "disapear" from the settings. My question is, how can i make it appear there again, to be able to hear the sound via the headset? Thank You all for help.
For some more settings I would advice to install pavucontrol. It saved me some troubles diagnosing sound issues. It also will list any possible output where Ubuntu sound sometimes forgets to show outputs that should be available (though it keeps getting better: HDMI used to not show up; 1 update after 12.10 release it started showing up.
You too will be able to find your headset and control it from here.
If I recall correctly after I used pavucontrol to activate my hdmi ubuntu control picked it up too (but that might have been caused by an update too). Otherwise do not use Ubuntu sound settings but switch to this program since it also has far more options.
Command line install
or hit the button ...
if not already installed install pulseaudio-module-bluetooth, this will add the required pulse audio sink that is needed.
Then make sure in the bluetooth manager your headset is connecting to the audio sink. At this point it should also appear in pacucontrol, make sure it uses the high quality audio protocol.