I'm new to Ubuntu and Linux so don't know much about commands, config files etc.
Anyway some sounds are working on system - only system sounds like when you change the volume, or hold down backspace, but it seems like any other sound from other apps like Firefox don't work. A friend of mine tried something called espeak to see if it would work from terminal but that did not work either. However if I use headphones plugged directly into audio jack instead of monitor speakers through HDMI all sounds work, including from Firefox.
Any ideas? Thanks