Some years back I completely renovated 2 old sydney apartments, one above the other. The noise downstairs was terrible. Walking, talking, "activities of life" were hard to ignore.
When we pulled up the floor we used yellow tongue On the upstairs floor and pink insulation in the roof of the downstairs apartment. Im trying to remember if we stapled some sort of thin black rubber tubing (?) onto the top of the joists (memory fails me). The difference was absolutely incredible. Not a peep.
This might be good for the shed if you intend doing some late night noisings.
Page 26 of this discusses some acoustic properties:
http://www.chhwoodproducts.com.au/us...g_Brochure.pdf