35 ILCS 200/12-40
The assessment of any class of property or of any township or multi-township or part thereof, or any portion of the county, shall not be increased by an equalization factor applied by a board of review until the board has made one publication of notice in a newspaper of general circulation published in the county, of such proposed increase and has given an opportunity to be heard, within 20 days of the publication date, to the owners of the property affected or any one representing them, and other citizens of the territory. The assessor or chief county assessment officer shall have like opportunity to be heard thereon, except where such action is taken in individual cases upon complaint. The board shall hear any person, upon request, in opposition to a proposed reduction in the assessment of any person or territory.
35 ILCS 200/12-40