I was trying to fix my audio problems using suggestions from this forum. One of the comments suggested I execute this and only this:
killall pulseaudio
So I did, and I restarted my computer just in case, but all it did was remove my soundcard and I still couldn't hear anything. Now I don't know how to get my soundcard back.
Please note that I am extremely inexperienced when it comes to Ubuntu.
killall pulseaudio
should only kill the current running Pulseaudio process - not disable the sound card...