low sound on my refurbished HP ENVY 17-j013cl laptop that runs Windows 7.

I have a HP ENVY 17-j013cl that was refurbished and now runs Windows 7 and Firefox OS.  Windows 8 was there previously, but replaced.  I have some hearing loss, but even at max audio control panel settings AND max video volume sound within an item, like a YouTube video, I have difficulty hearing it.

Solution? Any add on widget/sort of thing?

THX