The invention relates to a coating for acoustic treatment at the surface of an aircraft, in particular at the leading edge such as the air intake of an aircraft nacelle, said coating including an acoustically resistive layer (28), at least one cellular structure (30) and a reflective layer (32), characterised in that it comprises ducts (34) arranged between said cellular structure (30) and the acoustically resistive structure (28), the ducts being each defined by a wall (36) separate from the walls of the cellular structure (30) and one end of the ducts being connected to a hot air supply.