The oscillation of a gas bubble driven by an acoustic field has been investigated using an electrochemical sensing technique. A low-resolution scanning electrochemical microscopy technique, employing an L-shaped microelectrode, has been employed to address the equator of a tethered bubble. Real-time mass transfer enhancements as the result of bubble wall motion have been detected using the electrochemical reduction of Fe(CN)(6)(3-). A comparison of the pressure threshold measurements of the onset of surface oscillations with a theoretical model is presented. Photographic evidence of the presence and shape distortions of the bubble surface is also demonstrated.