Abstract：To solve the intricate and lower accuracy problem in the conventional 1 /3 octave spectrum and weighting sound level algorithm, a new method was proposed, based on the decomposition of spectrum and weighted network interpolations. There was an in-depth analysis on obtaining 1 /3 octave spectrum based on FFT spectrum, the relationship between spectral amplitude and time-domain amplitude and the way of reducing amplitude error by windowed FFT. The interpolation method of weighting network was illustrated, and the error-prone points in the entire calculation process were pointed out. The experimental results verified that the developed method was of high-accuracy and high-speed.

Keyword：1 /3 octave;weighted sound level;noise measurement;windowed FFT;