I used to have many choices about sound/audio hardware:analogue sterio outputsurround sterio outputanalogue HDMI sterio output ... etcnow they seem missiong and also virtual box shows the message :No audio devices could be opened.obviously there is a problem with the sound drivers. I removed everything and re installed pulse and alsaI even reinstalled the kernelnothing seems to work by the way the sound works perfectly but I have these issues:when using headphones I must each timeuse alsamixer to unmute the headphones and increase their volumeand the sound does not go out by HDMI (to the TV monitor)$ inxi -ASSystem:    Host: mmmmmm-pc Kernel: 4.4.0-78-generic x86_64 (64 bit)       Desktop: MATE 1.16.1  Distro: Linux Mint 18.1 SerenaAudio:     Card Intel 7 Series/C210 Series Family High Definition Audio Controller       driver: snd_hda_intel       Sound: Advanced Linux Sound Architecture v: k4.4.0-78-generic$ 
Linux mint - How to reinstall sound drivers
linux;audio;alsa;pulseaudio