In most all scenarios the problem should be fixed using one of the solutions above. If you are still having issues you can try restarting the program that is not working or even restarting your system (complete reboot).
If there is still no sound than it could be your speakers are malfunctioning. You can test this out by connecting them to another device or test working speakers or headphones with your system where you previously had no sound.
Well… hopefully you have solved the problem and now have a better understanding of how to troubleshoot Sound issues. Hopefully the sounds of silence won’t be a source of frustration this time around.