Abstract
It is clarified that L_eq is available for slowly fluctuating noise what is called fluctuating noise. But the evaluation method of rapidly fluctuating noise, for example, impulsive or intermittent noise, is not yet established. In this experiment, three periodically non-steady noises-triangular, sinusoidal and rectangular noises-were used as test stimuli, the factors of level fluctuation-repetition rate (RR) and range of level fluctuation (W)-were set up widely from fluctuating noise to impulsive and intermittent noise, and PSE (point of subjective equality), which was steady noise level equivalent to non-steady noise no noisiness, was searched for by constant method. The relation between PSE and fluctuation factors was investigated to obtain fundamental data to evaluate general non-steady noises on noisiness. The results and discussions are summerized as follows. 1) The PSEs of periodically triangular, sinusoidal and rectangular noises are significantly affected by RR and W. 2) Triangular and sinusoidal noises indicate similar tendency on noisiness and their PSEs can be represented by L_eq and the effect of level fluctuation, which is indicated as a function of RR and W by equation (4). 3) The PSEs of rectangular noises are larger than those of triangular and sinusoidal noises.
