• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.540-543
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• 2011

The vehicle's warning sounds are one of the important parts of overall vehicle quality, so the study of these sounds is increasing. In this study, the experiment of reproducing performance related to speaker position was studied. Based on the result of jury test, sound analysis method was developed to reflect the perception of warning sound according to vehicle speed and the development process of warning sounds was suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.165-170
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• 2014

Quantifying the perception of human is of great interest for the optimal characterization of the interaction of persons with their environment. The direct approach to such measurements is based on jury-test methods. In this study we considered which jury-test method is more efficient and exact way to measure the preferences for operating sound of car. Moreover we needed to research selection criteria of jury-test methods in accordance with the properties of sound samples. We choose two sample sounds; door locks which generate simple impact sounds and window lifts which are consisted of long and complex sound. For each sound sample we conducted two jury-test methods respectively and discussed about the results.

• Korean Journal of Audiology
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• v.25 no.2
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• pp.80-88
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• 2021

Background and Objectives: Non-linear frequency compression (NLFC) technology compresses and shifts higher frequencies into a lower frequency area that has better residual hearing. Because consonants are uttered in the high-frequency area, NLFC could provide better speech understanding. The aim of this study was to investigate the clinical effectiveness of NLFC technology on the perception of speech and music in patients with high-frequency hearing loss. Subjects and Methods: Twelve participants with high-frequency hearing loss were tested in a counter-balanced order, and had two weeks of daily experience with NLFC set on/off prior to testing. Performance was repeatedly evaluated with consonant tests in quiet and noise environments, speech perception in noise, music perception and acceptableness of sound quality rating tasks. Additionally, two questionnaires (the Abbreviated Profile of Hearing Aid Benefit and the Korean version of the International Outcome Inventory-Hearing Aids) were administered. Results: Consonant and speech perception improved with hearing aids (NLFC on/off conditions), but there was no significant difference between NLFC on and off states. Music perception performances revealed no notable difference among unaided and NLFC on and off states. The benefits and satisfaction ratings between NLFC on and off conditions were also not significantly different, based on questionnaires, however great individual variability preferences were noted. Conclusions: Speech perception as well as music perception both in quiet and noise environments was similar between NLFC on and off states, indicating that real world benefits from NLFC technology may be limited in Korean adult hearing aid users.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.80-88
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• 2021

Background and Objectives: Non-linear frequency compression (NLFC) technology compresses and shifts higher frequencies into a lower frequency area that has better residual hearing. Because consonants are uttered in the high-frequency area, NLFC could provide better speech understanding. The aim of this study was to investigate the clinical effectiveness of NLFC technology on the perception of speech and music in patients with high-frequency hearing loss. Subjects and Methods: Twelve participants with high-frequency hearing loss were tested in a counter-balanced order, and had two weeks of daily experience with NLFC set on/off prior to testing. Performance was repeatedly evaluated with consonant tests in quiet and noise environments, speech perception in noise, music perception and acceptableness of sound quality rating tasks. Additionally, two questionnaires (the Abbreviated Profile of Hearing Aid Benefit and the Korean version of the International Outcome Inventory-Hearing Aids) were administered. Results: Consonant and speech perception improved with hearing aids (NLFC on/off conditions), but there was no significant difference between NLFC on and off states. Music perception performances revealed no notable difference among unaided and NLFC on and off states. The benefits and satisfaction ratings between NLFC on and off conditions were also not significantly different, based on questionnaires, however great individual variability preferences were noted. Conclusions: Speech perception as well as music perception both in quiet and noise environments was similar between NLFC on and off states, indicating that real world benefits from NLFC technology may be limited in Korean adult hearing aid users.

• Journal of Music and Human Behavior
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• v.21 no.2
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• pp.107-134
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• 2024

This study aims to classify the semantic words commonly used to evaluate sound quality and to analyze their differences in reflecting the level of musical stimuli. Participants were thirty-one music majors in their 20s and 30s, with an average of 9.4 years of professional training. Each participant listened to nine pieces of music with variations in texture and instrument type and evaluated them using 18 pairs of semantic words describing sound quality. A factor analysis was conducted to group words influenced by the same latent factor, and a multivariate ANOVA determined the differences in ratings based on texture and instrument type. Radar charts were also drawn based on the identified sets of semantic words. The results showed that four factors were identified, and the word pairs 'soft-hard,' 'dull-sharp,' 'muddy-clean' and 'low-high' showed significant differences based on the level of musical stimuli. The radar charts effectively distinguished the sound quality evaluations for each music. These results indicate that developing Korean semantic words for sound quality evaluation requires a structure different from the previous categories used in Western countries and that linguistic and cultural factors are crucial. This study will provide foundational data for developing a verbal sound quality evaluation framework suited to the Korean context, while reflecting acoustic attributes in music listening.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1871-1876
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• 2010

The reduction of vehicle interior noise has been the main interest of NVH engineers. The driver's perception of the vehicle noise is strongly affected by the psychoacoustic characteristics of the noise and the SPL. The existing methods to evaluate the SQ for vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of subjective SQ values by neural network. However, these methods strongly depend on jury tests, this leads to difficulties. To reduce the important of the jury tests, we suggest a new method using the Mahalanobis distance for SQ evaluation. And, the optimal characteristic values that influenced the results of sound quality evaluation on the basis by main effect. Finally, we developed a new method based on the MD method to evaluate sound quality. The result of noise evaluation revealed that the sound quality could be well improved by changing the structural characteristics of the vehicle.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5936-5954
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• 2018

Eight out of the top ten the largest technology companies in the world are involved in some way with the coming mobile VR revolution since Facebook acquired Oculus. This trend has allowed the technology related with mobile VR to achieve remarkable growth in both academic and industry. Therefore, the importance of reproducing the acoustic expression for users to experience more realistic is increasing because auditory cues can enhance the perception of the complicated surrounding environment without the visual system in VR. This paper presents a audio downmixing system for auralization based on hardware, a stage of sound rendering pipelines that can reproduce realiy-like sound but requires high computation costs. The proposed system is verified through an FPGA platform with the special focus on hardware architectural designs for low power and real-time. The results show that the proposed system on an FPGA can downmix maximum 5 sources in real-time rate (52 FPS), with 382 mW low power consumptions. Furthermore, the generated 3D sound with the proposed system was verified with satisfactory results of sound quality via the user evaluation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1276-1279
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• 2006

This article on environmental noise qualify is concerned with the relationships between the annoyance and perception and sound quality metrics according to exposition time for traffic noise. For invested the characteristics of noise quality, we conducted to the subjective experiments of the annoyance response using the absolute 100 scaling method for the traffic noise sources. The traffic noise sources are composed to varieties exposition time from 15sec to 1200sec. As the results, the first there are decreased the perception loud level for the increase of exposition time with logarithm scale, but increased the annoyance. Second, evaluation index of annoyance is correlated to the loudness(sones), tonality and logarithm scale time with R2=0.83. Also, the composition ratio of traffic noise according to exposition time has the change of range as the logarithm scale ($30{\sim}50%$), tonality($27{\sim}37%$) and loudness($34{\sim}20%$).

• Asia Pacific Journal of Business Review
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• v.4 no.1
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• pp.35-44
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• 2019

Service quality is a competitive weapon in the banking industry. Better understanding of customer's perception of service quality in the banking industry and the drivers of such perceptions will be a sound basis for continuous improvement in the quality of service offered to customers, customer satisfaction and customer retention in the industry. An earlier study by the same authors (Ibrahim and Bokkasam, 2016) revealed that the six SERVQUAL determinants are significantly related to and explain about 84% of overall customer satisfaction. It was also observed that the female customers perceived higher level of positive perception towards SERVQUAL determinants. The present study carries out a micro-analysis of the influence of gender on the constituents of the service quality and customer satisfaction for all the six dimensions of the SERVQUAL: Access, Communication, Competence, Tangibility, Empathy and Reliability, in Saudi banking sector. The study also analyses gender-wise levels of satisfactions with regard to individual components constituting various factors of the constituents of SERVQUAL. It was observed that the male customers have significantly low levels of satisfactions with regard to promptness in solving conflicting issues and comfort during waiting time in the bank.