Abstract：In order to solve the problem that the correlation delay time (τ) of the traditional autocorrelator-based experimental system is too large when detecting the air free-field sound pressure, an anechoic box environment was built, a non-fixed-frequency-shift optical system, and a signal acquisition and processing system were designed for detecting the air free-field sound pressure based on the photon correlation method. The method decreases the step value of autocorrelation delay time (τ) to 1 μs, reducing the measurement error of sound pressure by 0.2 dB compared to traditional autocorrelator-based experimental systems. Comparing the measurement results of air field sound pressure between the microphone method and the optical autocorrelation method for 106.4 dB sound waves in the frequency range of 600 to 1200 Hz, the maximum deviation in measurement is 0.6 dB.
2024, Vol. 45 
