Pitch can refer to intonation, but it can also refer to the overall level of brightness in tone that a speaker consistently maintains. For example, I've read and heard that BrE speakers generally speak with a higher pitch than AmE speakers. Of course, each individual is different, but by listening to the BBC World Report on NPR, I think there's at least some truth to this. I would say it's accurate to say so.
The higher one's pitch is, the louder one's voice will sound. To the extent that pitch is like intonation, there is the potential for misunderstandings when we consider pragmatic language. As well, there is the potential for simply not being understood at all by using intonation and stress patterns in both words and phrases that are foreign and unfamiliar to native speakers.