Polycom SoundStructure C16 Design Manual page 711

Designing Audio Conferencing Systems
In a room that has sound-reinforcement with inappropriately high gain
settings, there is no longer any such thing as a "side conversation". Everyone
in the room will likely be able to hear all conversations, making it impossible
to have side comments that are private.
With reinforcement applications, remember that the key to success is setting
the appropriate performance expectations with the end user and it is the
responsibility of the conference room designer to set that expectation.
C - 29