Problem 4: Having all that, we should be done, should not we? Well… no! I still hear nothing!
Playing a sound was surprisingly difficult, given browsers usually now limit that websites (browser extensions are basically websites) should not play a random sound out of nowhere.
I am still trying here, but depending on how you load the sound file, you may end up getting weird errors.
The worst thing is that you need to copy the sound element to have multiple sound effects starting at the same time, so they can overlap each other.