Is noisy bad?

Well, school started, life got busy, Aggie football season is upon us, and I have not blogged in quite a while :)

While discussing the learning environment with my colleagues, the topic of compliant students arose.  Is it a misconception that compliant = engaged?  Are we as educators (specifically secondary) able to distinguish between strong classroom management skills and a compliant unengaged classroom?  How can we work to help others recognize this?  What level of comfort do we have with multiple activities, conversations, etc taking place at the same time?  Is noisy bad?

I have many elementary educator friends who are brilliant at managing centers, guided reading, and computers in one short segment.  Students are self directed, there are multiple things happening at once.  How can we bring this idea to the secondary environment?  Help!