• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.909-917
• /
• 2007

Recently the trend of automobile industry is that IQS evaluation index against a sensitivity quality is increasing. To reduce rattle noise due to speaker sound at low frequencies, it is required the advanced investigation of a package tray panel and a door module panel. This paper optimized the design parameters of package tray panel according to the theoretical background about robust design and suggested the design guideline for resonance avoidance and the reduction of vibrational sensitivity considering the excitation frequency of woofer speaker. In addition, it is suggested the design guideline of a door module panel through the sensitivity analysis in case of the speaker excitation. Finally, the design factor analysis of the quality deviation of a mother-car will make it possible to guarantee the stable characteristics of vehicle vibration in the early stage of vehicle development. These improvements can lead to shortening the time needed to develop better vehicles.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.8
• /
• pp.673-682
• /
• 2007

Recently the trend of automobile industry is that IQS evaluation index against a sensitivity quality is increasing. To reduce rattle noise due to speaker sound at low frequencies, it is required the advanced technology analysis process of body structure. This paper optimized the design parameters of package tray panel according to the theoretical background about robust design and suggested the design guideline for resonance avoidance and the reduction of vibrational sensitivity considering the excitation frequency of woofer speaker. And this paper described the design process of a door module panel through the sensitivity analysis in case of the door speaker excitation. Finally, the analysis of the quality deviation using mother car is suggested to guarantee the stable characteristics of vehicle vibration in the early stage of vehicle development. These improvements can lead to shortening the time needed to develop better vehicles.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.9 s.114
• /
• pp.897-903
• /
• 2006

The reduction of the vehicle interior noise has been the main interest of noise and vibration harshness (NVH) engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the heating, ventilation and air conditioning (HVAC) system sound among the vehicle interior noise has been reflected sensitively in psychoacoustics view point. Even though the HVAC noise is not louder than overall noise level, it clearly affects subjective perception to drivers in the way of making to be nervous or annoyed. Therefore, these days a vehicle engineer takes aim at developing sound quality as well as reduction of noise. In this paper, we acquired noises in the HVAC from many vehicles. Through the objective and subjective sound quality (SQ) evaluation with acquiring noises recorded by the vehicle HVAC system, the simple and multiple regression models were obtained for the subjective evaluation 'Pleasant' using the semantic differential method (SDM). The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Furthermore, the neural network (NN) model were obtained using three inputs(loudness, sharpness and roughness) of the SQ metrics and one output(subjective 'Pleasant'). Because human's perception is very complex and hard to estimate their pattern, we used NN model. The estimated models were compared with correlations between output indexes of SQ and hearing test results for verification data 'Pleasant'. As a result of application of the SQ indexes, the NN model was shown with the largest correlation of SQ indexes and we found possibilities to predict the SQ metrics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.819-820
• /
• 2011

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.24 no.4
• /
• pp.289-298
• /
• 2014

Pass-by noises of various trains were recorded by binaural recorder. The measured noises were evaluated using a sound pressure level and psychoacoustic metrics objectively. To analyze a binaural effect on annoyance that can be caused by train noise, auditory experiments were performed. Through the experiments, the annoyance differences between monaural and binaural train noises, the annoyance differences due to measurement angle and the annoyance differences due to kinds of train and measurement distance were determined. A correlation analysis was conducted to determine which index can affect the annoyance more strongly. As the result, a maximum rate of change of sharpness difference between left and right channels was proposed to predict the annoyance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.630-633
• /
• 2007

This paper proposes method to find the subjective satisfaction index of an air-conditioner using consumer's sensory evaluation for an air-conditioner. A satisfaction index of an air-conditioner is presented the annoyance and freshness as ${\alphs}$, ${\beta}$ exponents of 1/f slope and is changed the annoyance and freshness as exponents of 1/f slope are changed. The satisfaction index of an air-conditioner is not improved if SPL is above the proper level although the 1/f slope has optimal ${\alpha}$, ${\beta}$ values. Therefore, this paper proposes the satisfaction index of an air-conditioner considered both SPL and ${\alpha}$, ${\beta}$ exponents of 1/f slope.

• The Journal of the Acoustical Society of Korea
• /
• v.11 no.2
• /
• pp.50-58
• /
• 1992

To improve the quality of dwelling environment of domestic apartment house, it is required to establish the sound insulation standard and the performance evaluation method which is suitable to the domestic residential conditions. In this study, the properties of internal noisy sources of a single unit in apartment houses and the sound insulation performance of party walls are investigated and analyzed, as a primary step to the establishment of sound insulation standard. Based on these data, the differences in sound insulation index of each plane type are investigated along with their causes. Also, the factor which affect and decide the insulation performance are analyzed in an effort to improve the performance of party wall structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.796-801
• /
• 2004

The thing that should be considered preferentially when we introduce sounds to the space we are living in is to clarify the notion - for whom when, what kinds of sounds, where, for what and how to. There are two physical habitate conditions which affect the quality of soundscape. The one is 'Background sound' of the space which should be masked or applied in accordance with its qualify. The other is features of the habitat which would be the factor building up ambience and the index for us to decide specificities of the sounds to be introduced. Selecting or producing the sounds to be introduced, we should consider those to make these represent the community, influence people's behavior, be in harmony with surroundings, and give the identity to the space. There are two ways to introduce the sounds. The one is to put sound sources which actually make the sound. The other is to put the sounds without practical sound source but with objects related to those. For later, it's important not to introduce the sounds people prefer but what would be in harmony with the place. In this study, we've researched what kinds of sounds could be utilized for soundscape designing. And, we've studied if those can be, how those should be introduced and what other factors should be considered.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.69-74
• /
• 2006

It is known that the various noise sources which are engine, transmission, tire, intake system, etc exist at vehicle driving status. Specially noises which cannot be expected by a driver induce unpleasantness to all passengers. These noises are difficult to distinguish noise sources or specifications because of too many vehicle parts. Therefore in this paper, study on abnormal noise of bush on suspension system is performed by the measurement and analysis of the noises of bushings that are generated artificially. The measured noises are analyzed by two points-view of spectrum and sound quality. Finally, it is shown that the noise sources of bushings on the suspension system which are the pillow ball joint bush of a control arm and the rubber bush of a lower arm could be distinguished by the spectrum distribution and a index value based on tonality.

• Journal of Korean Society for Quality Management
• /
• v.48 no.3
• /
• pp.409-420
• /
• 2020

Purpose: The purpose of this study is to develop a measurement scale for evaluating the auditory affect of automobile engine sounds. Methods: In order to collect affective vocabulary, literature review, user tests, and expert interviews were conducted. Affective vocabulary related to automobile engine sounds was selected through three methods. To develop the evaluation scale, open/close card-sorting and expert interview-based survey method was used. Results: The results of this study are as follows; In order to select the main affective vocabulary from the collected vocabulary, 39 vocabularies with a frequency of 5 or higher were selected as vocabulary expressing the main auditory affect of automobile engine sounds. Each affective vocabulary is divided into three di- mensions, it was confirmed that the conceptual model for the auditory affect of automobile engine sounds is composed of three levels: intuitive, descriptive, and evaluative of hierarchical structure. As a result of the study, four indices of intuitive dimension, seven indices of descriptive dimension, and one index of evaluative dimension were derived from the evaluation scale of the auditory affect in an automobile engine sound. Conclusion: The auditory evaluation scale developed in this study can be used to systematically measure and evaluate the auditory affect of automobile engine sounds.