Abstract: The present invention relates to a hydrophone specifically designed for use in high pressure shock wave fields, comprising a thin piezoelectric polymer film secured to a rigid hoop structure, having a centrally located active element and two conducting leads extending from the active element on each side of the film. Under the action of high pressure shock waves, the conductive material which makes up the active area electrode and the conductive leads is slowly removed, altering the hydrophone's sensitivity and eventually rendering it unusable. The present invention provides an improved design for a hydrophone which monitors the loss of electrode and lead integrity due to shock wave action so that the hydrophone may be replaced before it produces invalid readings. The leads on each side of the centrally located active element are electrically switched to measure the resistance between the leads and the central portion.