1. A multi-mode speech communication system having a plurality of different operating modes for a plurality of different speech applications, the system comprising: a speech service compartment that contains a plurality of system users; a plurality of input microphones within the service compartment that develops microphone input signals from the system users to the system; a plurality of output loudspeakers within the service compartment that develops loudspeaker output signals from the system to the system users; a signal processing module in communication with the speech applications and including: an input processing module that processes the microphone input signals to produce a set user input signals for each speech application that are limited to currently active system users for that speech application, and an output processing module that processes application output communications from the speech applications to produce loudspeaker output signals to the system users, wherein for each different speech application, the loudspeaker output signals are directed only to system users currently active in that speech application; wherein the signal processing module dynamically controls the processing of the microphone input signals and the loudspeaker output signals to respond to changes in currently active system users for each application.