| With the development of industrial technology, more attentions have been paid on the sound quality of noise. This thesis conducts some researches in sound quality of motorcycle based on the result of domestic and oversea. The main contents are as followings: Firstly, a summary of research on subjective evaluation is given and then a brief introduction of psychoacoustics as a theoretic basis for subjective evaluation is presented with some basic concepts, frequently used parameters, some problems need consideration and methods in experiments. Then several typical noise sample of 15 types of 125ml motorcycle is provide at the jury test to obtain the subjective evaluation of various types of population. By analyzing the subjective evaluation results of different genders, ages, and professions of the population, we finally get the correlation between the results of the subjective evaluation and the parameters of objective psychoacoustics through linear regression. The thesis presents some applicable measures to improve the sound quality of motorcycle by analyzing the frequency component of well-accepted noise samples with the combination of psychoacoustics parameters. To obtain a better sound quality, it is necessary to increase the power of low frequency while decrease the power of high frequency to reduce sharpness of the noise and rationalize the noise frequency spectrum structure. With some experiments, we analyze the influence of some different psychoacoustics parameters over motorcycle sound quality. Loudness and sharpness are of great importance to the sound quality of a motorcycle while roughness and fluctuation strength is of little importance. With the increase of age, people are less sensitive to sharpness while more sensitive to loudness. To a male sharpness and loudness are almost of the same importance in evaluating a sound quality and the former is of a slim advantage. But to a female, more contribution is given to loudness while sharpness counts for a little.
|
PDF Full Text Request