• The Journal of the Acoustical Society of Korea
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• v.40 no.6
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• pp.566-570
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• 2021

This study presents a perceptual difference in acceleration sounds of a sporty sedan between the driver and passenger. We found a significant difference in annoyance and sportiness perception according to the acceleration sound level through subjective evaluations. The multimodal reproduction system, which can reproduce the driving image, motion, vibration, and sound, was applied for the test. A subjective experiment was conducted to evaluate the perceived intensity of annoyance and sportiness by varying the acceleration sound level in five steps of 3 dB. The experimental results showed that the driver perceives the acceleration sound less annoying than the passenger at a relatively low sound level. Meanwhile, the driver has perceived the acceleration sound more sporty than the passenger at a relatively high sound level. Moreover, it was found that passengers were 35 % less sensitive to an annoyance than drivers, whereas the driver was 74 % more susceptible to sportiness than passengers according to the sound level change. This finding is expected to be applied as a sound design strategy that differentiates the acceleration sound level in active sound design.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.3
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• pp.258-266
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• 2013

This paper presents the correlation between psychological and physiological acoustics for the automotive acceleration sound. The research purpose of this paper is to evaluate the sound quality of acceleration sound of a passenger car based EEG signal. The previous method for the objective evaluation of sound quality is to use sound metrics based on psychological acoustics. This method uses not only psychological acoustics but also physiological acoustics. For this work, the sounds of 7 premium passenger cars are recorded and evaluated subjectively by 33 people. The correlation between the subjective rating and sound metrics is calculated based on physiological acoustics. Finally the correlation between the subjective rating and the EEG signal measured on the brain is also calculated. Throughout these results the new evaluation system for the sound quality on the automotive acceleration sound of a passenger car has been developed based on bio-signal.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.1
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• pp.3-9
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• 2003

In an apartment building, the impact sound from upstairs has been regarded as a main source of noise causing discontentment among occupants. To set the optimum design for sound insulation. it is nesessary to suggest the useful tools or technique that predict the floor impact sound. The purpose of this study is to investigate the applicability of the theory of sound radiation. We measured the vibration acceleration levels on the interior structures and predicted the sound pressure level of the room by using them. The result show that the predicted value, in general, were in good agreement with the measured values within 5∼10% in error rate.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.100-106
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• 2017

Sound quality engineering in automobile noise applications has become more and more important under the current quiet driving condition because various noise components masked under high noise level can be audible in quieter driving situation. Many researches have been carried out for subjective and objective assessments on automobile sounds and noises. In particular, the interior sound quality has been one of research fields that can give high-quality feature to automobile products. Although many works related to the interior sound quality have been progressed or completed in foreign countries, limited research results are presented in the country. In the study, subjective assessments are first performed with 20 subjects to select perceptual adjectives suitable to the assessment of car interior noises during acceleration. The selected perceptual adjectives are employed as the assessment scales to evaluate the acceleration noises in questionnaire procedures using 35 subjects, for which several noises are created through digital filtering of the acceleration noises measured. Mean values and standard deviations for subjective assessment scores obtained by the questionnaire procedures are calculated and their reliability are also verified. Finally, various statistical analyses such as the correlation analysis and the factor analysis are carried out to reveal the interrelationship between the assessment scales and the spectrum components of the acceleration noises.

• Interaction and multiscale mechanics
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• v.3 no.4
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• pp.373-387
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• 2010

This study is intended to assess low frequency sound radiated from a viaduct under normal traffic. The bridge comprises steel box girders and wide cantilever decks on which vehicles pass. The low frequency sound and the acceleration response of the bridge under normal traffic are measured to investigate how bridge vibrations affect the low frequency sound observed near the bridge. Observations demonstrate that strong relationships exist between frequency characteristic of bridge's acceleration response and the sound pressure level of low frequency sound. A noteworthy point is that the dynamic feature of the sound pressure level is mostly affected by dynamic feature of the span locating near the observation point.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.187-191
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• 2001

Sound quality engineering in automobile noise applications has become more and more important under the current quiet driving condition that the interior noise level is below 65 dBA, because various noise components masked under high noise level can be audible in quieter driving situation. Many researches have been carried out for subjective and objective assessments on automobile sounds and noises. In particular, the interior sound quality has been one of research fields that can give high-quality feature to automobile products. Although many works related to the interior sound quality have been progressed or completed in foreign countries, limited research results are presented in the country. In the study, as a base step necessary to objective assessments on car interior noises, subjective assessments are performed with 20 subjects. For this purpose, perceptual adjectives suitable to the assessment of acceleration noises are selected as assessment scales through questionnaire procedures using 35 subjects. Mean values and standard deviations are calculated for noises created through digital filtering of acceleration noises measured. In addition, the correlation analysis and the factor analysis are carried out to investigate the dependence of the assessment scales selected.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.390-393
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• 2005

In this study, examined heavy-weight floor impact sound to rahmen structure(steel reinforced concrete structure) and bearing-wall structure(box frame type structure) that have slab thickness of 4 form at a standard laboratory through noise and vibration measured. The results of ANSYS modeling of structures was predicted that the nature natural frequency increased according to change of thickness of each slab by finite element analysis, and acceleration value decreased. Rahmen structures compares with bearing-wall structure, nature frequency was predicted low. Measurement results of natural frequency and acceleration level for structures at a standard laboratory, tendency department such as ANSYS modeling appeared. Rahmen structures appeared that reduction effect is less in Acceleration level and heavy impact sound transmission level comparing with bearing-wall structure.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.796-801
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• 1994

Measuring noise, sound quality or acoustical comfort presents a difficult task for the acoustic engineer. Sound and noise are ultimately jugded by human beings acting as analysers. Regulations for determining noise levels are based on A-weighted SPL measurement performed with only one microphone. This method of measurement is usually specified when determining whether the ear can be physically damaged. Such a simple measurement procedure is not able to determine annoyance of sound events or sound quality in general. For some years investigations with binaural measurement analysis technique have shown new possibilities for the objective determination of sound quality. By using Artificial Head technology /1/, /2/ in conjunction with psychoacoustic evaluation algorithms - and taking into account binaural signal processing of human hearing, considerable progress regarding the analysis of sounds has been made. Because sound events often arise in a complex way, direct conclusions about components subjectively judged to be annoying with regard to their causes and transmission paths, can be drawn in a limited way only. A new procedure, complementing binaural measurement technology combined with mulit-channel measuements of acceleration sensor signals has been developed. This involves correlating signals influencing sound quality, analyzed by means of human hearing, with signals form different acceleration sensors fixed at different positions of the sound source. Now it is possible to recognize the source and the transmission way of those signals which have an influence on the annoyance of sound.

• The Journal of the Acoustical Society of Korea
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• v.26 no.6
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• pp.235-242
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• 2007

The test and evaluation of floor impact sound is mainly conducted before move in the residence. Floor impact sound generating is actually the conditions in which a heavy load like a curtain and furniture is installed, the situation before and after move in the residence is different. In this study, we investigate the floor impact sound variations according to the live load installation like furniture in the source room. The vibration acceleration level and floor impact sound level variation were measured before and after live load ($200kg/m^2$) installation in the floor impact sound test building and the field. The difference was not large although the vibration acceleration level and the floor impact sound level were reduced through measurement result of load installation. Resonance frequency was not changed by load installation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.150-155
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• 2006

Speech intelligibility is investigated on a conference room-window glass coupled system. Using MLS(Maximum Length Sequency) signal as a sound source, acceleration and velocity responses of the window glass are measured by accelerometer and laser doppler vibrometer. MTF(Modulation Transfer Function) is used to identify the speech transmission characteristics of the room and window system. STI(Speech Transmission Index) is calculated by using MTF and speech intelligibility of the room and the window glass is estimated. Speech intelligibilities by the acceleration signal and the velocity signal are compared and the possibility of the wiretapping is investigated. Finally, intelligibility of the conversation sound is examined by the subjective test.