Well, I've been a user of Ubuntu 12.04 LTS since April now, and it's been a very pleasant experience. I'm a big fan of electronic music, and I tend to have my tracks playing in the background while I do things on my laptop, either in YouTube or in Clementine, my default music player. All has worked very well until now.
A couple of days ago my entire PC started to lag really badly. Almost everything was unusable. I opened up System Monitor via the terminal to find a process called "pulseaudio" using nearly 1GB of RAM and over 80% of my CPU. I needed to get some important work done and so I killed the process without thinking.
Once again today, pulseaudio decided to lag the hell out of my PC, and so I killed it again. Nothing seemed to happen immediately, but once I opened up YouTube all the audio on videos stuttered a lot, while the videos played smoothly. I restarted Firefox to find that the audio was now not working at all, with both headphones and speakers, and the volume up quite a bit (it's not muted, I've checked that!).
A little bit of research later and I've discovered that pulseaudio plays an important part in Ubuntu's audio. Even after restarting my PC the audio still ceases to work in any applications or with any output. The pulseaudio process refuses to start up again.
So, can you help me out here? What can I do to fix my problem, and why was pulseaudio doing this in the first place?