US Patent 11495201 Sound absorption panel

In a sound absorption panel formed by stacking a plate perforated with a hole having a hole size smaller than a fiber length such as expanded metal, a honeycomb material, and felt-like fiber between the perforated plate and the honeycomb material, and joining the perforated plate, the felt-like fiber, and the honeycomb material to each other with an adhesive, the adhesive applied to the perforated plate is permeated into a surface of the felt-like fiber exposed from the hole to fix the fiber on the surface.