Genuinely curious... lingustic question.?

I am NOT saying this as a racist question, I genuinely want to know: whenever I hear Chinese or Japanese people talking together, it seems that they speak with a very loud voice; is this just the way I hear it, are their voices naturally shrill, or does the language demand that they intone in this fashion? I mention it because it occasionally causes mild annoyance when I am travelling by bus or Metro in Downtown Montreal, to myself and other passengers. Is it a cultural, a linguistic, or just a perceptional thing?