How to export X Display with Audio?

///OLD: Left just in case! This worked for me

edit /etc/group

sudo nano /etc/group

Next, search for audio, you shoud find somethink like this:

audio:x:29:pulse

Add a coma and your username afther pulse

audio:x:29:pulse,username //whatever your username actually is

change username with the one you wish to log in!!!

Save and restart ubuntu, it should work. If I switch between sessions(Cn+Alt+F7), I loose sound in the one I started, just to let you all know. I suppose it is a bug.

///OLD

EDIT: According to Reinis(see comment below) it is not recommended to edit the file manually. It's better to :

sudo adduser _username_ audio

Change username with your actual username. Restart :)