I recently purchased an Asus ZenBook 3 to replace my aging Thinkpad X220. Most things work right out of the box just fine, but I noticed the audio function controls having no affect on the actual volume of the laptop.
After a bit of Googling, I came upon an old Ubuntu Forums post with a solution to my problem. Credit goes to a user named hanni_ali.
Taking Back Controls
First, we find and edit the PulseAudio config file for analog output:
Then, we locate the following configuration entry:
And replace it with:
Finally, we save the file and reboot the laptop. When things are all started up, the volume controls should work!