No airport zoning regulations shall be adopted, amended, or changed under this Act except by action of the Department, or by action of the legislative body of the political subdivision in question, or by action of the joint board provided for in Section 14, after a public hearing in relation thereto, at which parties in interest and citizens shall have an opportunity to be heard. Notice of the hearing shall be published at least once not more than 30 nor less than 15 days before the hearing in a newspaper of general circulation in the political subdivision or subdivisions in which is located, wholly or partly, the airport hazard area to be zoned or, if no newspaper is generally circulated in any such political subdivision, then in a newspaper of general circulation in the county in which such political subdivision is located.