NOVELTY - The interlayer film comprises two individual films of plasticizer-containing polyvinyl acetal, in which a first individual film comprises a polyvinyl acetal with a content of polyvinyl acetate groups of 0.1-11 mol.% and a second individual film comprises a polyvinyl acetal with a content of polyvinyl acetate groups of 5-8 mol.%. The polyvinyl acetate group contents and/or plasticizer content are different in the respective films. The second individual film comprises a polyvinyl acetal with a content of polyvinyl alcohol groups of less than 14 wt.%.    USE - The interlayer film is useful for laminated glass and in a windshield, facade element or film of photovoltaic modules (claimed), where the windshields or side windows are useful in automotive sector and the laminated safety glass is useful in construction sector.    ADVANTAGE - The interlayer film can be produced at reasonable cost by selecting the plasticizer-containing polyvinyl acetals with improved sound-absorbing characteristics and adequate damping characteristics.    DETAILED DESCRIPTION - The interlayer film comprises two individual films of plasticizer-containing polyvinyl acetal, in which a first individual film comprises a polyvinyl acetal with a content of polyvinyl acetate groups of 0.1-11 mol.% and a second individual film comprises a polyvinyl acetal with a content of polyvinyl acetate groups of 5-8 mol.%. The polyvinyl acetate group contents and/or plasticizer content are different in the respective films. The second individual film comprises a polyvinyl acetal with a content of polyvinyl alcohol groups of less than 14 wt.%. The individual films have a plasticizer content that differs by 5 wt.%. The first individual film comprises a polyvinyl acetal with a content of polyvinyl alcohol groups of 17-22 wt.%. The individual films further comprise 0.001-20 wt.% of silicon dioxide. The interlayer film is: produced by coextrusion of the individual films; fully or partially pigmented; and made of a three layer ABA construction, in which the A layers of the ABA construction comprise a first individual film and the B layer comprises a second individual film.. A test piece produced with the interlayer film of 2 mm glass/0.8 mm interlayer film/2 mm glass has a first mode damping value of greater than 22% in accordance with ISO/PAS 16940 at 10 degrees C. An INDEPENDENT CLAIM is included for an improvement in a windshield, facade element or film of photovoltaic modules containing a polyvinyl butyral film.