# To install Alsa sound (alsa-base, alsa-utils, alsa-tools and libasound2) enter this command:
sudo apt-get install alsa alsa-tools

# Add yourself to the group audio:
sudo adduser username audio

# Reboot System to take effect
sudo init 6

# Alsamixer is sometimes muted by default, so you might need to unmute it. Run alsamixer:
alsamixer