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.