(mag nē, tō strik’ sh∂n) Change in the strain of a magnetic material as a result of changes in magnetization. The dependence of magnetization (susceptibility or remanence) on applied stress is termed inverse magnetostriction or piezomagnetism. Magnetostrictive acoustical sources and hydrophones are extremely rugged. A magnetostrictive hydrophone might consist of a coil of wire wrapped around a cylinder of magnetostrictive material. A pressure wave acting radially induces hoop-stresses in the core that changes its permeability and thereby the flux linking the coil wrapped around it. The change of flux induces a voltage that is proportional to the derivative of the pressure-wave signal.