Papers by Keyword: Sound Quality

Abstract: Many new Grand Theaters are constructed around China in recent years, and it is very important for architect to be familiar with the basic principle and knowledge of acoustics when designing the theaters. RT (Reverberation Time), ITDG (Initial Time Delay Gap), Loudness, BR, Surrounded sense and spatial sense are the major factors that affect the sound quality of the hall. All of them determine the different subjective feeling and quality of sound. According to the causes and requirements of these factors, the basic recommendations are put forward for theater auditorium hall design to ensure good sound effect.

Abstract: In 8 domestic car smooth acceleration to 80km/h when rear seat operator of ear noise samples as the evaluation object at idle condition, Cluster analysis theory, the subjective evaluation irritability of vehicle interior sound quality rating test method; Through the calculation of main psychoacoustic parameters all samples obtained value, the subjective evaluation results and psychoacoustic parameters calculated by correlation analysis and multiple linear regression analysis, established a quantitative model of loudness as noise annoyance index to describe the quality of the car.

Abstract: Loudness is one of the three basic parameters to assess the auditorium sound quality with reverberation time and balance together, it will be discussed in this paper. There are three expressions evaluating the loudness: listening level, the strength index and the mean forte sound pressure level of tutti-sound (LpF). Each of them has their merits and shortcomings. This paper will focus on these three expressions and the feasibility of checking and accepting acoustics of the hall by loudness.

Abstract: Vehicle acoustical comfort and vibration in a passenger car cabin are the main factors that attract a buyer in car purchase. Numerous studies have been carried out by automotive researchers to identify and classify the acoustics level in the vehicle cabin. The objective is to form a special benchmark for acoustics level that may be referred for any acoustics improvement purpose. This study is focused on the sound quality change over the engine speed [rp to recognize the noise pattern experienced in the vehicle cabin. Since it is difficult for a passenger to express, and to evaluate the noise experienced or heard in a numerical scale, a neural network optimization approach is used to classify the acoustics levels into groups of noise annoyance levels. A feed forward neural network technique is applied for classification algorithm, where it can be divided into two phases: Learning Phase and Classification Phase. The developed model is able to classify the acoustics level into numerical scales which are meaningful for evaluation purposes.

Abstract: This experiment collected sound signals of four different cars driving at different speeds on highway and replayed the noise samples with playback software HEAD Audio Recorder. The subjective evaluation tests were carried out with paired comparison method. Evaluating models between subjective evaluation and objective psychoacoustic parameters were established with SPSS analysis software.

Abstract: The wavelet packet decomposition method was used to two common insects song signal. Frequency decomposition and feature extraction were made, the feature vectors, eigenvalues and the sound quality evaluation parameter vectors were constructed, then the correlation analysis calculation were made between the eigenvalues and the sound quality evaluation parameter vectors. The results show that the correlation coefficients are good, the average correlation coefficients of cricket and grasshopper song signals are 0.8875 and 0.6942, the results of cricket is much better than grasshopper, it proved that the proposed algorithm is more suitable for cricket song signals analysis, a new and effective sound quality evaluation method for typical insect with friction sound mechanism is provided.

Abstract: The paper proposed a nanomechanical measurements method according to insect parts biometric friction sound, the nanomechanical measurements were carried out on the cricket and grasshoppers wings, meanwhile, two common insects song signal were collected and the sound quality evaluation parameter vectors were constructed from it. The correlation analysis calculations were made between the nanomechanical properties parameters and the sound quality evaluation parameter vectors. The results show that the nanomechanical properties of biological materials have relevance with the sound quality characteristics, and the average correlation coefficient of the cricket is better, the crickets elastic modulus correlation coefficient with loudness were with the highest average correlation coefficient.

Abstract: According to the complexity and non-linear characteristics of car interior sound quality evaluation, the technology of BP neural network is used in sound quality evaluation. The interior noise samples from actual cars were obtained by road experiment. The subjective evaluation test of sound quality annoyance was carried out. Meanwhile, several objective psycho-acoustical parameters of these samples were calculated. The sound quality prediction model of vehicle interior noise was established based on BP neural network. Annoyance of samples was obtained by means of the prediction model and the results were compared with that obtained by multiple liner regression prediction model. The results indicate that the prediction results from BP neural network model were close to the measured values. The BP neural network model was more effective than multiple liner regression model, and it can be used effectively to the evaluation of modern car noise.

Abstract: The interior noise samples from four cars at different positions and different speeds were selected as the evaluation objects. The subjective evaluation test of sound quality preference was carried out with paired comparison method. Several objective psycho-acoustical parameters of these samples were calculated. By way of linear correlation and multi-dimensional regression analysis, an equation between the subjective evaluation of noise preference and the objective psycho-acoustical parameters was established. The results indicate that the vehicle interior sound quality preference under the good highway and the constant-velocity driving conditions is affected mainly by two psycho-acoustical parameters Loudness and Sharpness.

Abstract: To meet the characteristic diversity need of noise source in the product sound quality research, a parameter-controlled noise generation method is presented. The developed method is based on speech signal processing and programming. The system architecture of the controllable noise source is studied, and the implementation method of each module of the system is detailed. Modular design achieves data transfer and parameter control flexibly and conveniently between modules such as system calibration, basic acoustic signal production and conditioning, audio output control. Programming implement a controllable noise source platform based on the Visual C + + with friendly interface and reliable output.