中文说明：A计权计算声压级，通过时域变换到频域，然后计算出每个频点的声压，计算三分之一倍频程和总声压以及A计权声压
English Description：
The sound pressure level is calculated by A-weighted method, which is transformed from time domain to frequency domain. Then the sound pressure at each frequency point is calculated, and the third octave, total sound pressure and A-weighted sound pressure are calculated