The Acoustical Association Ontario (AAO) is an Employers’Association, which represents approximately fifty (50) unionized contractors engaged in interior finishing construction in the Industrial, Commercial and Institutional (ICI) sectors of the construction industry in Ontario. Specifically, AAO members perform drywall, acoustic, insulation and fireproofing work throughout the Province of Ontario, including such areas as Windsor, London, Cambridge, Kitchener, Waterloo, Niagara, Hamilton, Toronto, Oshawa, Kingston and Ottawa.