Upon the filing of an application, the city commission shall fix a time and place for a public hearing thereon. Notice of such hearing shall be given to the applicant and to all persons to whom certificates of public convenience and necessity have been theretofore issued. Due notice shall also be given the general public by posting a notice of such hearing in the city hall. Any interested person may file with the city commission a memorandum in support of or opposition to the issuance of a certificate. (Prior code § 22-2-3)