When Will drunk dials Sue, he says "hey sexy lady" after he says "I know it's late and I know you're taken, I've had a couple drinks". When Sue is playing the voice message over the PA system, however, it starts with the "hey sexy lady" but then cuts straight to "there is something I really, really wanna say to you". It skips much of what he says the first time he drunk dials.
When Becky does the outro on the xylophone and Sue stops her, the speaker is already switched off so the students wouldn't even hear it.