Patent ID: 7654364

Claim:
A sound absorbing structure for suppressing noise generated on a sound source side, said sound absorbing structure comprising: A perforated panel having a large number of through holes and a fiber material, which are oppositely provided on said sound source side and provided so as to be stacked on each other; and An air layer provided behind said perforated panel or said fiber material, wherein said fiber material satisfies Equation 1 below and said perforated panel satisfies Equation 2 below: p×t≧ 0.01 kg/m 2 ; Equation 1: β≧10 x Equation 2: Where x=( 4/3×log 10 d−⅓) p: density of fiber material (kg/m 3 ) t: thickness of fiber material (mm) d: hole diameter of through holes of perforated panel (mm) β: aperture ratio of through holes of perforated panel (%).