ubuntu16.04 headphones don't sound resolved __ubuntu

Ubuntu16 headphones are not sound-resolved.
Http://www.linuxdiyf.com/linux/25058.html
After loading the UBUNTU16 and installed the Nvidia graphics drive, the installation of NetEase cloud music, suddenly found that the computer does not sound, using the following methods to solve.

First of all, enter the following command in the terminal, download the PulseAudio volume control software:
sudo apt install Pavucontrol
Terminal input instruction Pavucontrol, allows the software, found in the output device has two output devices, a Nvida digital audio, a built-in audio, Nvidia HDMI output device has been working, theoretically there is a sound output, but why I can not hear it.

Think about the HDMI that should be digital audio output, and headphones plugged in on the computer should receive analog signal output, so can not use the digital audio HDMI, so in the Software "Configuration" menu bar, HDA nvidia drop-down selection box, pull to the bottom, select "Off", turn off the output of this device, Then, in the built-in Audio Drop-down selection box, select Analog Stereo duplex.

Then the computer headset still doesn't sound, then back to the Output Device tab, we found that there is only a built-in audio device, select the "Port" in the dropdown box, select "Analog Headset", then if you have to open the music player in the headset will immediately make a sound.