This part of IEC 61094 - gives guidelines for the design of actuators for microphones equipped with electrically conductive diaphragms; - gives methods for the validation of electrostatic actuators; - gives a method for determining the electrostatic actuator response of a microphone. The applications of electrostatic actuators are not fully described within this standard but may include - a technique for detecting changes in the frequency response of a microphone, - a technique for determining the environmental influence on the response of a microphone, - a technique for determining the free field or pressure response of a microphone without specific acoustical test facilities, by the application of predetermined correction values specific to the microphone model and actuator used, - a technique applicable at high frequencies not typically covered by calibration methods using sound excitation.