A Research On The Subjectivity Of The Automobile Interior Noise Sound Quality

The design of contemporary automobile inclines to be lighter and high-speed, which increases the vibration and internal noise, especially the low-frequency noise in the car. Therefore, the performance of comfortableness will directly impact on the brand image and market share of the manufacturers, and reducing the noise becomes an crucial factor for the manufactures peremptorily when they are capturing the market advantages or opportunities. Currently, main-stream auto makers in succession set the comfortableness, particularly lowering the internal noise as a vital index of automobile design.On the part of the research of comfortableness, it focuses attention on setting the decibel of internal noise in the rival cars as a target parametric index, and then reduces the index of internal noise trough optimization the configuration and parameters. Contrastively, there are rare enterprises which enhance their market share form the perspective of customer subjective experience. Consequently, it puts forward a solution aimed to reduce internal noise from the customer experience. It sets customer experience as a reference index of improving the comfortableness, which is suitable for the product design stage took the factors of customer needs into consideration when it makes alterations of the vehicle structure.Firstly, this paper simplydescribes the sources of internal noise, and based on this fact, it proposes a conventional limited standard which couldn't meet the subjective evaluation, so this paper introduces an concept of sound quality and comes up with an evaluation filed of psychoacoustics on the basis of human auditory system and its basic characters, meanwhile it presents a method combined with the theory of customer satisfaction which eventually will be applied in this thesis,namely, that's rough hierarchicalanalysis process which is designed to conduct subjective evaluation on the internal noise.Secondly, based on acoustics relevant theories, the subjective evaluation on noise will be elaborated from perspectives of conventional evaluation, psychological sound and comprehensive aspects, meanwhile it selects unbiased fidgety degree in comprehensive evaluation indexes as a subjective evaluation parameter in accordance with the requirements of the dissertation.Ultimately, it properly chooses customer wants and compiles questionnaire in line with the requirements of analytic hierarchy process, selecting appropriate people to express their opinions of noise level in a certain car. Then it will process the data with rough analytic hierarchy process as to find the basic significances of customers, which will be given appropriate rectifications applied with Kano Model and the market competitive analysis afterwards, and eventually obtain the final significance of customer needs.