We describe the measurement of the response, ς, of the potential of a metal electrode to elastic strain under open circuit conditions. The experimental response exhibits a frequency dependence due to Faraday loss currents, which become negligible beyond 30 Hz. For a (111)-textured gold film the experimental value at higher frequency, ς = −1.83 V, compares well with the intrinsic value of Au(111) predicted by recent ab initio computation.