Diffraction of acoustic waves on a half-plane in the case of impedance boundary conditions. Applications to sound barriers

A method is proposed and the simple analytical solutions are obtained for the diffraction problems of acoustic waves on a half-plane with the impedance boundary condition on its one surface and the Neumann or Dirichlet condition on the opposite surface. It is shown that the properties of these solutions are essential for the optimal design of barriers with sound-absorbing walls.