Specifications of both laboratory standard and measurement microphones are now defined in Parts 1 and 4 of IEC 1094 ``Measurement microphones,'' respectively. Methods for the absolute pressure calibration of these microphones are also defined in Part 2 of IEC 1094. These standards were published recently. In this report 1/2-in. condenser microphones were used, such as LS2aP/LS2bP: MR112, B&K4180, and WS2P/F: various measurement microphones including those of sound level meters, have been calibrated up to 20 kHz using two couplers: plane-wave and large-volume. Calibration data are compared to each other and the accuracy of the calibrated results are discussed in detail.