In the case of a proposed zoning ordinance or proposed zoning ordinance amendment, at least one (1) public hearing shall be held by the commission appointed to recommend zoning regulations. Not less than fifteen (15) days notice of the time and place of the public hearing shall first be published in an official paper or a paper of general circulation in the City. The hearing notice shall also contain either the text or a short summary of the regulatory effect of the proposed ordinance or amendment.