The objective SQE is based on the physical and psychological objective parameters of sound. The advantages and disadvantages of sound are evaluated by testing and analyzing these objective parameters, and the annoying reasons are determined according to the simulation modifications of sound frequency, envelope, modulation and amplitude modulation. The purpose of objective SQE is to establish the relationship between subjective perception of SQ, physical acoustics and psychoacoustics, that is, to understand subjective attributes of noise SQ from the perspective of physical acoustics and psychoacoustics. Many experts and scholars have put forward some basic parameters of psychoacoustics after long-term theoretical and experimental research to quantify the subjective evaluation of sound objectively. The purpose of objective SQE is to establish the relationship between subjective perception of SQ, physical acoustics and psychoacoustics, that is, to understand subjective attributes of noise SQ from the perspective of physical acoustics and psychoacoustics. Many experts and scholars have put forward some basic parameters of psychoacoustics after long-term theoretical and experimental research to quantify the subjective evaluation of sound objectively. The objective SQE method is based on the rational application of psychoacoustic parameters, that is, by extracting objective parameters of sound and establishing mathematical models to characterize sound characteristics, such as loudness, sharpness, roughness, tonality, fluctuation strength, and SPL. In recent years, researchers have been studying how to use quantitative methods to describe the subjective SQE, that is, to combine objective evaluation with subjective evaluation, and to establish an objective SQE model based on psychoacoustic evaluation parameters. The final research criterion of SQ is human auditory perception. Although some objective parameters can be used to describe and improve evaluation efficiency, people are the ultimate recipients and judges of sound, and the SQ study cannot be conducted without people’s subjective involvement. However, the consistency and repeatability of subjective evaluation experiments are poor, which requires a lot of human resources, material resources and time. Therefore, objective and subjective SQE shave distinct application characteristics. If the subjective and objective results have good consistency, the advantages of subjective and objective evaluation can be combined—this is the starting point of studying the subjective and objective unified model. The objective evaluation mainly studies and establishes the intelligent SQE model of vehicle noise and makes an accurate quantitative estimation of SQ. The objective evaluation includes establishing the evaluation model and testing prediction performance. The establishment of the model requires three elements: mapping method, extraction of sound features of noise samples and subjective evaluation of results, among which mapping method and extraction of acoustic features are the key points of sound objective evaluation.