A calculation of Lx and Leq noise evaluation indices by use of statistical information on the noise level fluctuation, and its microcomputer-aided on-line measurement

Abstract In this paper, a precise calculation method of L x and L eq noise evaluation indices is theoretically proposed using the statistical information on the noise level fluctuation. More specifically, this method is given in a generalized form universally applicable to the arbitrary non-Gaussian distribution, including a well known simplified expression derived under the assumption of a standard Gaussian distribution as the first approximation. Furthermore, based on this estimation method, a specific on-line measurement system is constructed with the aid of a microcomputer by introducing an iterative process for extracting the statistical information on the noise level fluctuation. Finally, the effectiveness of the proposed method has been confirmed experimentally by applying it to actual road traffic noise.