Internal combustion engine`s e.g. diesel engine noise qualitative analyzing method for vehicle, involves assessing audible degree of modulation with assessing function, and forming noise index based on assessed modulation frequency spectrum

摘要

The method involves forming envelope curve for a band-pass-filtered signal of frequency bands, and considering temporal masking corresponding to human auditory perception in the curve. The remaining degree of modulation in each band is calculated based on the masking, and a level-dependent masking is calculated for each band. The remaining audible degrees of modulation are calculated for all bands, and the audible degrees of modulation are assessed with a frequency-dependent assessing function. A noise index is formed based on an assessed modulation frequency spectrum. An independent claim is also included for a method for determining force at a central point of load transmission of a vehicle body.