Recording Level Monitor:
Checking your output sound is easy as you can just play any Mp3 file etc. & hear it playing, but you might also want to check recording from a microphone (known bug) or some other external source. One of the easiest way’s to do this is to use the Recording Level Monitor.
This handy little programme is installed by default in Ubuntu, but is normally hidden on Gnomes Applications menu.
Unhide it by doing the following..
Navigate to Applications/Accessories/Alacarte menu editor in the top Gnome panel, click on Sound & Video within the newly opened programme (left hand pane of window), then make sure that recording level monitor option (in the right hand pane) has a tick in the box next to it.
Once that’s done close the Alacarte programme, as you won’t be needing it any more & start the recording level monitor from the menu. Leave it running until you’ve finished testing the sound.
Double click the speaker icon (on the top Gnome panel) to start the volume control application.
Open the Preferences option from the Edit menu.
Enable (by placing a tick next to them) the following options..
Everything else can be left disabled.
Click the close button to save the changes.
Click on the Capture tab that should now have appeared within the volume control application & move the volume slider to about a third of the way up.
Next click on the Options tab that has been added & make sure that the first Input Source is set to Mic & the second one is set to CD.
Don’t close down the volume control application just yet, as you first need to check that the microphone is working ok.
Plug in your microphone, start up the Recording Level Monitor & start chatting. You should see the bars on the Recording Level Monitor lighting up, as you talk. If it’s not working, then this is due to a bug in Ubuntu (already reported it to the devs) & it will take an extra step to get your microphone working..
Go back to your volume control application, click on the Options tab, change Mic to front Mic & then change it back again straight away.
Check your microphone again now, as it should work fine.
Unfortunately you will probably have to do this every time you turn on/restart your computer, or resume from suspend/hibernate.
This will be fixed soon I hope.