One way sound proofing

    Why not develop wave barriers that allow true one way sound and light proofing.
    The idea involves the use of nonlinear materials that only allow waves to pass through from one direction. Nonlinear materials respond to the attributes of the waves, and stacking these materials in specific arrangements should allow waves from one direction to pass through while blocking waves from other directions.
    The idea remains theoretical, and no true one way material have been produced yet. However, the potential applications in acoustics could prove interesting.