Is it rude to talk loudly in a restaurant?

If nobody else is and your voice is carrying.

have you ever eaten at a Hard Rock cafe? you practically have to scream at each other.

oh hell yea! hate it when someone is on the next table & is speaking loudly - not saying talking shld be banned but when there are others, don't go so loudly! Was out last week within friends & someone on next table was so loud (and drunk!) i barely cud hear my mates!

i would consider it rude to speak loudly pretty much anywhere

If you're outright yelling out then yes.

Oh gawd yes,

it's rude.