The regional committee on school district organization shall also hold a public hearing or hearings on any proposed plan: PROVIDED, That three members of the committee or two members of the committee and the educational service district superintendent, or his or her designee, may be designated by the committee to hold such public hearing or hearings and to submit a report thereof to the regional committee. The regional committee shall cause to be posted, at least ten days prior to the date appointed for any such hearing, a written or printed notice thereof in at least three prominent and public places in the school districts involved and at the place of hearing.