(1) The hearing board shall select from its number a chairman.
(2) The hearing board may hold a hearing en banc or may designate two (2) or one (1) of their number to hold a hearing.
(3) If two (2) or three (3) members of the hearing board conduct a hearing the concurrence of two (2) shall be necessary to a decision.
(4) The hearing board, not less than two (2) being present, may, in its discretion, within thirty (30) days rehear any matter which was decided by a single member.