Abstract: An active noise control system (500) includes a structure (80) and a plurality of piezoelectric speakers (10). The piezoelectric speakers (10) are disposed on a surface (80s) of the structure (80). The piezoelectric speakers (10) each have a radiation surface extending along a first direction (D1) and a second direction (D2). The first direction (D1) is a direction along which centers of the radiation surfaces of the piezoelectric speakers (10) are arranged so that the piezoelectric speakers (10) are adjacent to each other. The second direction (D2) is a direction orthogonal to the first direction (D1). The radiation surface of each of the piezoelectric speakers (10) is shorter in a dimension (L1) in the first direction (D1) than in a dimension (L2) in the second direction (D2).