US Patent 11514879 Sound absorbing apparatus and sound absorption structure

A sound absorbing apparatus includes a first member including at least one first opening portion for enabling Helmholtz resonance, and a second member that is on the first member, has a plate shape or a sheet shape, and is formed of a porous material. The second member includes at least one second opening portion overlapping one-to-one with the at least one first opening portion in planar view. A periphery of each of the at least one second opening portion coincides with or is located outside a periphery of each corresponding one of the at least one first opening portion in planar view.