A method for determining one or more material conditions of a hysteretic ferromagnetic material and/or a nonhysteretic material can include interrogating the hysteretic ferromagnetic material and/or the nonhysteretic material with an input time varying magnetic field and detecting a magnetic response and/or acoustic response over time from the hysteretic ferromagnetic material and/or the nonhysteretic material. The method can also include determining a time dependent nonlinear characteristic of the received magnetic response and/or acoustic response and correlating the time dependent nonlinear characteristic of the received magnetic response or acoustic response to one or more material conditions of the material.