Our Bella, a 5 month old boxer, is VERY vocal. She does a high-pitched version of the woo-woo thing whenever she is happy. I have to explain to people that she does that when she is happy because she goes crazy around people. It is like the cry of the banchee. She does something similar when she wants something or has to do something she doesn't want to. She will also sigh and groan then too. When she gets really worked up she will bark, but we try not to react to that. She knows the speak command, but will not learn the 'no speak' command. Overall, it is really cute. She is nothing but sweet. In fact, she is trying to get on my lap now in a tiny computer chair at 40 lbs.
-Jill