Here is project I did in Rimouski through a residency at Caravanserail. Great town, wonderful people who are obsessed with ice, ice fishing and le banquise (ocean ice sheet) that forms every year. Le banquise acts as an extension of the public space of the city of Rimoiski. The ice sheet is moving up and down with the tide, sometimes by 4-5m so one must know what one is doing or at least listen to someone who does.
I made a machine that casts blocks of ice with one convex parabolic surface. The curve is accurately made by slowly spinning the form while the blocks freeze. Inter-cooled air from a blower lifts the form with 50kilos of water and helps the freezing process and aids in the formation of clear ice. Excess pressure from the blower is released by jets on the end of the form for the slow, even spin.
Once formed, the blocks can be stacked to create a low or a tall wall which can be used to reflect one's voice to another "transmitter" and to another person.