I have idea using another insulation material: Hollow Fiber. Too is a fiberous material.
Can found inside the pillows.
Hollow fibers are polymeric fibers that have a continuous hole running down the middle; the hole is created by the introduction of air or other gas (nitrogen) in the polymeric solution (in wet spinningprocess) or by melt spinning through speciallydesigned spinnerets.
Such structure would have air inside its lumen which increases the air volume in the fabric and, in turn, increases its ability to absorb sound waves rather than reflecting it.
What do you mean about this?
At least looks as more healthcare material without sound quality decreasing