[skalos]

I have made a few panels surfaced with used wine corks.  From these I think I will get some absorption because of the soft material used, and some diffusion because of the shapes and surface of the corks. 

Anyone know how much absorption and diffusion I might get?

All I know is they look good to me and I really enjoyed "making the corks available for this purpose."

[Pez]

I don't think you'll get any absorption worth mentioning. It might be a little better than bare walls. And diffraction will depend on how you cut the cork. Did you stagger the different corks size or are they all the same? If they are the same then no diffraction. Maybe post a pic.

[richidoo]

The depth of the phase grate diffusor determines the low freq diffusion limit, while the narrowness of the cells determines the high freq limit. Random element heights make it diffuse without lobing. You have none of those factors in the cork board, so no diffusion. Cork is soft but is not permeable to air pressure so there is no absorption, except maybe a tiny amount by turbulent friction in the spaces between the corks.

If you keep drinking wine enough to get more corks, you can start gluing them together in a way that does diffuse sound, like this. Don't forget to leave some places empty to get extra depth.

[Rob Babcock]

I doubt it will hurt anything...and it probably looks pretty cool!

[Bob in St. Louis]

I've got a couple dozen corks I've been "saving" for some reason. They're yours if you want them. Honestly though, I think you'd have to have a wheelbarrow load to make a difference.

But it would look very cool. 

Bob

[Rob Babcock]

Not exactly PC.