Soundproofing coating comprising a cellular structure formed in a thickness of the coating between an open first face, permeable to acoustic waves, and a closed second face formed by a closure sheet, characterized in that the cellular structure is made up by joining, in a so-called transverse direction, several structures, each of said structures being formed by joining, in the transverse direction, a first longitudinal strip of a first geometry with a second longitudinal strip of a second geometry, the first strip and the second strip forming a structure being configured so that each structure exhibits successively and repeating in the longitudinal direction: - a first cavity extending between the first face and the second face and open at the first face and of which the cross section narrows progressively between the first face and the second face until said first cavity becomes closed, - a first joining of two walls (71, 72) belonging respectively to the first strip and to the second strip in contact with one another over part of the thickness of the coating so that a passage is created between the first cavity and a second cavity, - said second cavity, which has a cross section that increases progressively between the first face and the second face and which is closed at the first face and at the second face of the coating by the closure sheet, - a second joining of two walls (91, 92) belonging respectively to the first strip and to the second strip in contact with one another over all or part of the thickness of the coating. characterized in that the cellular structure is made up by joining, in a so-called transverse direction, several structures, each of said structures being formed by joining, in the transverse direction, a first longitudinal strip of a first geometry with a second longitudinal strip of a second geometry, the first strip and the second strip forming a structure being configured so that each structure exhibits successively and repeating in the longitudinal direction: - a first cavity extending between the first face and the second face and open at the first face and of which the cross section narrows progressively between the first face and the second face until said first cavity becomes closed, - a first joining of two walls (71, 72) belonging respectively to the first strip and to the second strip in contact with one another over part of the thickness of the coating so that a passage is created between the first cavity and a second cavity, - said second cavity, which has a cross section that increases progressively between the first face and the second face and which is closed at the first face and at the second face of the coating by the closure sheet, - a second joining of two walls (91, 92) belonging respectively to the first strip and to the second strip in contact with one another over all or part of the thickness of the coating. - a first cavity extending between the first face and the second face and open at the first face and of which the cross section narrows progressively between the first face and the second face until said first cavity becomes closed, - a first joining of two walls (71, 72) belonging respectively to the first strip and to the second strip in contact with one another over part of the thickness of the coating so that a passage is created between the first cavity and a second cavity, - said second cavity, which has a cross section that increases progressively between the first face and the second face and which is closed at the first face and at the second face of the coating by the closure sheet, - a second joining of two walls (91, 92) belonging respectively to the first strip and to the second strip in contact with one another over all or part of the thickness of the coating.