I wanted to show my kid how the music scores work so installed NtEd. Unfortunately the sound was not produced, the only way to workaround was to export to midi and play using some MidiPlayer (tmidity or sth.). I tried to fix the problem so installed ALSA mixer and some other stuff available through Ubuntu SW Center, even tried GNU Denemo. It all failed, so uninstalled all of that (I suppose, I went through history in software Center), but a strange thing occurs. Now, once OS loads I hear white noise out of speaker, and can not control it through standard volume control app which comes with Ubuntu (11.04 using). Mute does not work (on both mic and speakers), and it looks signal from mic is directly routed to speaker (when I am closing the laptop I can hear feedback at high frequencies.
Any idea how to disable it and back to normal ?
Thanks in advance.