Strange bug

so lately, i have been getting this very unique bug where after getting to summoner's rift, i end up with NO sound at all, the announcer lines (like killing spree, double kill, minions have spawned, etc..) appear and disappear right after, and i have mini interference-like freezes every 5 secs. but the worst part that sometimes, together with no sound i enter the EMPTY rift, like cant see any living thing like champs or minions, nor towers, only the empty plain rift... Anyone has an idea what is causing this ?