Entitlement to expression

I have been challenged lately by the concept of "entitlement to expression".  What factors influence whether someone is able to speak their mind or whether in their doing so they are impacting negatively on others or being destructive to the resolution of the issue at hand?

 Obviously there are guidelines for communicating effectively such as wisdom in one's choice of words, appropriate timing, awareness of the environment in which the conversation is taking place etc but I think what fascinates me is something beyond this.  

Let me use an example to showcase my point.  Often in committee meetings animosity is shown towards certain individuals when they raise a point and yet when another person makes the same point later in proceedings it is openly accepted and embraced.  

It is complex.  No doubt there are factors such as historical experiences between individuals, the tone and manner with which the point is made, the dynamic between individuals and the meeting facilitator, but is there something else?  

I am inspired to focus my energy toward answering this question because I believe it holds the key to genuine, high quality, community engagement.  How can we allow ALL voices to be heard, properly and effectively, in a way that allows for the most progressive, wholesome outcome possible?  To do this the volume will need to be turned up for some and down for others - the question is, which ones need to go which way and how is this best achieved?