paul khristunov pavel come in, good afternoon, it will come in handy for us.nt with wood fiber boards made from softwood. this is spruce pine, the bonding agent in them is resin, which is good, this material, and due to the fact that it is porous. it is also like, uh, stone wool, in the intervals between the fibers it is extinguished by sound, but besides this, the fibers themselves are, if you take a cell, and wood is cellulose, it is hollow inside, like human hair or like wool, and therefore the sound is extinguished. even inside we have, uh, several cubes from different materials column with sound. we downloaded a chic drill sound. and now we will use a sound level meter to see how the sound spreads there, how much it dampens. well , it's noticeably quieter. here's the rumor and less, 82 the next cube of drywall. noticeably quieter. 10 db better than drywall daria we are testing a sample of wood fiber board. somewhere around 70.5 a little, but we better complicate the task, let's test the cube of two layers of drywall and fiberboard 66 and finally the last