The person in charge of long discussions is the chairman, or the speaker. They also say who gets to talk and for how long.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
The chairman got through the crisis.
The man in the black suit sitting in the last row of the bus is the speaker.
I am acting as chairperson of this meeting.