The idea is amazing. I would give it 5 stars if it gave the option to lower or set the volume of ALL videos coming from a particular webpage (for instance 9gag).

For some reasons videos from 9gag are EXTREMELY loud.

Youtube didn't have any audio and I checked all other settings + devices. This fixed it as soon as I installed. THANK YOU

I listen to game sound tracks on youtube - Super Mario World and the like - and very often, certain instruments play only in one ear, some in the other, which can be jarring. Thankfully, this extension exists. Now I can blast music in my ears all night long while cramming for my exams, and it sounds just the way it used to when I played the games on my old mono TV. The gain slider also helps me find that sweet spot where the sound is just perfect. Dear lovely dev, you just made my life SO much better. Thank you so much! <3
(found this extension as one of the top google search results on a reddit post)

Can you rename (add tags) to something like Volume Sound Booster Normalizer Normalization? I couldn't find this addon for few days!

good!

i have the youtube+firefox bug combo where the sound volume always is maxed out no matter what. This addon claims to work on youtube. It doesn't work, on youtube or anywhere else. Absolutely pointless, and it requires the permission to check on your browsing activity.
How it managed to get a 5 stars rating is beyond me.

App works for browser Twitch, and I'm super thankful because my comp volume is cranked just to hear a lot of streamers. Wish the gain could go up a little higher still though. But that's because Twitch/streamers, not poor design.

Is useless, as the setting resets even on page reload.

Does not work with different playpack speed for YouTube

Installation aborted because the add-on appears to be corrupt.

SoundFixer works well on non-cross-domain sites so I can hear what's going on through my not state of the art speakers. Unfortunately, when I leave a site after using SoundFixer, the volume level is reset very low, so the next time I go to a cross-domain site I'm up a crick and can't hear a thing.

Doesn't work at all