Acoustic laminated glazing, acoustic interlayer and method for selecting the interlayer for optimal acoustic damping

Laminated glazing (2) comprising a viscoelastic plastic insert (3) comprising at least two damping films (30, 31) each having a loss factor tan δ greater than 0.6 and a shear modulus G′ less than 2×107 Pa over two temperature ranges tA et tB respectively, characterized in that the film which has, at a frequency of 200 Hz, the highest loss factor tan δ over a given temperature range included within the temperature range tA or tB, has an equivalent shear modulus G′eq less than the equivalent shear modulus or moduli of the other film or films, with G eq ′ = G ′ ⁢ e tot e where G′ is the shear modulus of the material constituting the film, e is the thickness of the film and etot the total thickness of the insert.