An acoustic panel for a turbine engine includes a first strip and a second strip each comprising an alternation of first ridges and second ridges connected by sidewalls. The first and second strips are joined to each other to form a plurality of cells, each delimited by a first ridge of the first strip and a first ridge of the second strip. A third strip is interposed between the first strip and the second strip and includes a first lateral wall bearing on the first strip The third strip further includes at least one tab that extends inside one of the cells and delimits all or part of a passage inside the associated cell.