Magnetic Tape/Magnetic Tape Head:

The magnetic tape head is fastened to the bottom of the structure and the magnetic tape fabric is placed on the floor beneath the structure. The idea is that when the structure is blown up or deflated it would cause the magnetic tape head on the bottom of the wall to move over the magnetic tape fabric on the floor producing a sound.

This could also be reversed by placing the magnetic tape head in the floor and wrapping the bottom of the structure with the magnetic tape fabric.