I have also face similar issues. Our school is set up in a pod style, so there are six classrooms in a pod area surrounding a common area. None of the classrooms have doors. To start off, I was really the only teacher in my pod doing a lot of WBT. There were some complaints about the noise level at first, but since then there are times when we are really quiet even though we are using WBT. The great thing about WBT is that you can really control the level of your class. You can have a super excited classroom, or a quiet, excited classroom. One of my favorite lessons was one when we were doing shared reading on the carpet, and I was practically whispering, so my kiddos did too. It was a blast and they loved it. Of course, there are times when you want to celebrate or do something loud and over the top. I agree with Deb about checking with your neighbors and working out a quiet riot time. Also, I presented to my entire building on WBT, and that got a lot more teachers on board. I haven't had near the problems with our voice levels since the presentation and some of them have been trying it in their classrooms. They see the benefits, so they are more supportive. It doesn't sound like you are going to get that right away, so I would try the quiet riot that Deb mentioned and try quieting your tone, because you will see that the students will follow.
Staci