I always forget and search why when I create new user and I have no sound but in root acount I can hear any sound from my speaker.
It solved by adding username user that have no sound to file /etc/group,
Open /etc/group file with your fav editor and find line with "audio" in begining and add a username with problem in the end line, like this:
audio:x:29:yihaa"yihaa" is username with audio problem. save file you have editted and problem solved.
