It is important that you understand the difference between the word Allow and Automatic. You want ALLOW,
Enabling on Chrome:
Go to the lock on the left side of the URL input box and click. That will reveal a permission menu. If you have a sound setting on that menu, make sure it says ALLOW not automatic. If not, choose ALLOW.
If you do not have a sound setting then click on the Site settings at the bottom of the menu:
Once in Site settings, scroll down and find sound and set to Allow.
Enabling on Firefox:
Go to the lock on the left side of the browser’s URL input box, click to reveal the permission menu. If you have Autoplay make sure it says Allow Audio and Video.
If you do not have an Autoplay setting go to the blue shield to the left of the lock and click:
On this menu select Protection Settings and click:
Once the protection settings menu is up, scroll down until you find Autoplay and click on settings:
Click on Allow Audio & Video and you should be all set!