A new type of electromechanical coupling is postulated to explain the polarization signals resulting from the shock loading of nonpiezoelectric materials. The driving force is viewed as being proportional to the gradient of the stress. The electromechanical coupling constant is found for an ionic solid by deriving the effect for a linear ionic chain. A stress gradient of 1011dyn/cm3is found to give rise to a voltage gradient of 10 V/cm.