To estimate the interior noise level of railway vehicles after implementing noise-abatement measures, it is crucial to accurately evaluate the difference in sound transmission loss before and after the noise-abatement measures. In this study, we attempted to evaluate the effectiveness of noise-abatement measures using a statistical method, aiming to enable rapid on-site evaluation by objectively evaluating differences in sound transmission loss. As a result, we confirmed that even for frequency bands where the difficult to determine significant differences and required discussion using the conventional evaluation method based on the mean value and 95% confidence interval of sound transmission loss measurements, significant differences could be objectively determined through the application of permutation testing. This approach shows promise for enabling rapid on-site evaluations.
N. Tomita (Wed,) studied this question.