Some embodiments are directed to an elementary acoustic metamaterial cell, including a body made of solid material and at least one resonator defining a groove of width l and depth p, the groove being open on the surface of the body, wherein the depth p is set by a resonant frequency (f) of the cell according to a relationship x, c being the speed of sound in air and the width l is set by an energy density confined in the cell according to a logarithmic relationship Emax αlog (l) determined experimentally, the groove having an acoustic absorption controlled by a ratio between the depth p and the width l of the groove. Some embodiments are also directed to an acoustic screen including such an elementary cell.