MICROPHONE SENSITIVITY CALIBRATION UNDER HIGH INTENSITY SOUND

In this paper, the change of sensitivity of the condenser microphones CH 16 and BK 4136 etc. are estimated and calibrated under the high intensity sound. Sensitivity of microphone as described above was calibrated by high pressure microphone calibrator Type 4221, the range of sound pressure level was from 140 dB to 161. 6dB. In general, the maximum change of sensitity for these microphone was less than 0.3dB. As compared with the result of pistonphone calibration, the maximum difference was less than 0.4 dB, it was within the limits of experimental error. In addition, the similar experiments were carried out under the high intensity sound from 168 dB to 173 dB and the same result was obtained. The experiment results were in agreement with the results of the theoretical analysis. The method has proved that microphone sensitivity calibrated by pistonphone can be used for the microphones intended for high intensity sound (below 170dB).