• 한국소음진동공학회논문집
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• 제16권5호
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• pp.457-469
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• 2006

In automotive engineering, the brand sound is one of the important advantage strategies in a car company. For the design of brand sound, the selection of descriptive word for a car sound is one of major works in automotive sound quality research. In this paper, booming and rumbling sound, which are professional words used by sound and vibration engineers are used for the design of brand sound. We employed sound quality metrics, which are used in the psychoacoustics. By most research results, the relationship between subjective evaluations and sound quality metrics has nonlinear characteristics. In order to correlate these subjective evaluations with sound quality metrics, the artificial neural network technology has been applied to two-dimensional sound quality index for a passenger car. These indexes are used for 46 passenger cars, which are samples of the famous cars around the world. Also a preference evaluation for car sound was carried out by sound and vibration engineers. We coupled this preference with booming and rumbling sounds by using artificial neural network. In future, the two dimensional sound and preference index will be very useful to develop brand sound in passenger cars.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.174-179
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• 2005

In automotive engineering, the brand sound is one of the important advantage strategy in a car company. For the design of brand sound, the selection of descriptive word for a car sound is one of major works in automotive sound quality research. In paper, booming sound and rumbling sound, which are professional words used by NVH engineers are used for the design of brand sound. We employed sound metrics which are the subjective parameter used in psychoacoustics. According to most research results, the relationship between subjective evaluations and sound metrics has nonlinear characteristics and is very complex. In order to link these subjective evaluations to sound metrics, the artificial neural network technology has been applied to two-dimensional sound quality index for a passenger car. These indexes is used for 46 passenger cars, which are samples of famous cars in the world. Also the preference in car sounds is evaluated by the trained NVH engineers. We coupled this preference with booming and rumbling sounds by using artificial neural network. In future, the two -dimensional sound index and preference index are very useful fur the development of brand sound in passenger cars.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1272-1275
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• 2006

The A-weighting curve, very well explain the human perception for various frequency, is used to assess the traffic noise as well as the environmental noise. However, it does not reflect the annoyance perception appropriately because it assesses the noise at an A-weighted equivalent noise level of 1 kHz. In this study, we acquired the sound quality of traffic noise included various frequency and studied the human perception caused by change of frequency range.

• 한국소음진동공학회논문집
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• 제16권8호
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• pp.797-805
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• 2006

The sound quality characteristics of refrigerator noise in an anechoic chamber and in a real living environment for 30 models of refrigerators were investigated. Subjective evaluation experiments were conducted to determine subjective tolerance level for refrigerator noise. Refrigerator noise was played from a loudspeaker at the position normally occupied by a refrigerator in a real living environment. A nine-point scale was used to measure subjective satisfaction of the sound pressure levels for refrigerator noise. Point 3 on the scale corresponded to a sound pressure level of about 30 dB(A). Seventy percent of the participants were satisfied with this level of refrigerator noise. A semantic differential test was also conducted to evaluate the sound quality of refrigerator noise. From the results of correlation and multiple regression analyses on the psychoacoustical parameters and subjective evaluations of 30 refrigerators, sound quality indices which predict the subjective rating score were proposed.

• 소음진동
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• 제10권2호
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• pp.254-260
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• 2000

the reduction of the interior nosie level has been the main interest of NVH engineers in the development of vehicles. However, the consumer's perception on the car noise is affected largely by the psychoacoustic characteristics of the noise, as well as the sound pressure level. In this study, the quality of the vehicle interior nosie is analyzed by employing the subjective evaluations and by representing them in temrs of the objective quantities. The subjective evaluatins were performed for the seven vehicles in the range of subcompact to luxury cars. The methods of paired comparisons and semantic differential were used to study the preference, the quality of interior noise and their correlation. The linear regression models were obtained for the subjective evaluation and the sound quality metrics.

• 한국자동차공학회논문집
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• 제18권5호
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• pp.37-44
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• 2010

Impact noise is induced in a car when it is driven on a harsh road or over some bumps. This noise occurs with the very high level of sound, which affects passengers in some way or other. Although it is impossible to clearly remove such noise, it is necessary to research an improvement in sound quality for impact noise. A new sound metric for impact sound is presented. This metric is verified by comparison between mean subjective ratings and several sound metrics. In this paper, more objective attributes are considered, which the attributes are expressing the level and modulation of sound. Three sound metrics are employed to get impact sound indexes for each course by the method of multiple linear regressions. The indexes are verified by considering the correlation between the estimated values from the multiple linear regressions and the mean subjective ratings by evaluators. Also, the subjective ratings on the indexes are estimated for the case in which some parts of suspension system are changed. The estimated ratings represent more reasonable or acceptable ratings. Thus, such indexes can be used for modification of the parts of suspension system under considering a good sound quality.

• 한국음향학회지
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• 제25권3호
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• pp.129-136
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• 2006

소음에 대한 인간의 심리적 인지는 소음의 여러 가지 물리적 요인에 의하여 영향을 받는다. 그러나 현재의 환경소음 평가는 A 가중치 등가 소음 수준을 기준으로 평가되고 있으며 인간의 다양한 감성적 요인을 반영하지 못하고 있다. 따라서 본 연구에서는 환경소음 평가를 위하여 환경소음원 43개에 대하여 주관평가와 통계적 분석방법을 사용하여 인간의 감성에 영향을 주는 음질인자 (Sound quality factor)를 분석하였다. 분석방법은 먼저 다양한 환경소음원에 대한 음질물리량 (Sound quality metrics)을 분석하여 음원을 분류하였으며 분류된 음원의 주된 음질 물리량을 고찰하였다. 그리고 쌍대비교법 (Paired comparisons method)과 어의분별척도법 (Semantic differential method)을 사용하여 주관 평가를 실시하고 음질의 요인을 분석하였으며 물리량과의 관계를 규명하였다. 마지막으로 요인에 대한 물리량의 기여도를 분석함으로써 환경소음의 감성적 인지에 대한 기초 물리량을 설정하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.661-665
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• 2006

This study investigates objective and subjective evaluations of refrigerator noise. To describe the fluctuations like a click, a rapid increase of sound level, a change of pitch, a transition into the stationary and ending phase, the psychoacoustical and autocorrelation function(ACF) parameters have been employed. First, subjective evaluation of the noisiness of 24 kinds of refrigerators was conducted. Then, the relationship between objective measures of the refrigerator noise on perceived noisiness was examined with multiple regression analyses. Sound Quality Indices using the psychoacoustical and ACF parameters were also developed. The important psychoacoustical parameters for evaluating noisiness are loudness and roughness of stationary phase. The relationship between the noisiness and the ACF parameters shows that sound energy ${\Phi}(0)$ and its fluctuations are important. Also, refrigerator sounds that had a fluctuation of pitch were rated as more annoying. The fluctuation of pitch is expressed by ${\tau}_1\;and\;{\Phi}_1$ defined by the delay time and the amplitude of the first peak of the ACF.

• 한국소음진동공학회논문집
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• 제17권5호
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• pp.398-404
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• 2007

In this study, the sensitivity of annoyance was investigated by the subjective jury test for the variations of the frequency components along with various sound pressure levels of sixteen environmental noise sources. Annoyance was, also, evaluated for the road traffic noises. Sound pressure levels were $54{\sim}84\;dB$ which individually divided frequency components with eight bands of equally three bark bands. The results show that vehicle traffic noise is recognized as the most serious environment noise source. The sensitivity of human perception of annoyance in frequency bands is quite different from A-weighting curve. The annoyance found out to be more sensitive in high frequency region and reached its maximum in 3.4 kHz.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.268-271
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• 2008

A sound-masking technique was applied to the urban public spaces with multiple noises in order to reduce the annoyance of the construction and traffic noise. In addition, the effects of masking system were investigated in order to improve the soundscape. In several urban spaces, building construction and nearby road traffic noise were recorded using a head and torso simulator and sound quality (SQ) system which specifies the spectral and temporal aspects of the noises. The sound-masking system which consists of the distributed speakers and control devices was applied to the boundaries of the construction sites. Synthesized masking sounds were produced with consideration of SQ characteristics of the multiple noise. Subjective evaluations on the soundscape were conducted to verify effectiveness of the system under the conditions with and without the masker sounds.