I don't understand threads on the relationships board when people say things like "all couples argue" and "we row fairly often like most couples" and "we shout quite often". If that's the case, surely you're in the wrong relationship?
I think arguing is a sign that you are invested in a relationship, not ever disagreeing suggests you don't care and have checked out of the relationship.
I do suspect there is some semantics going on here, really what's the difference between annoyed voices, heated discussion, niggles, disagreements, arguments, text ding dongs, raised voices, shouting, a row? All sound like arguments to me although if someone feels unsafe like a couple of the PPs then that is obviously not OK.
Shouting is something that can happen when you're happy (heard the neighbours shouting with excitement during the cricket world cup final, kids shout and scream in the garden when they are having fun) or when you are dealing with lots of people and need to be heard above the chit chat. A raised voice is not always worse than a quiet voice; you can whisper a threat. Shouting is not inherently bad.