Development of a sound quality index for the wash cycle process of front-loading washing machines considering the impacts of individual noise sources

2015 ◽  
Vol 87 ◽  
pp. 183-189 ◽  
Author(s):  
Un-Chang Jeong ◽  
Jin-Su Kim ◽  
Jae-Eun Jeong ◽  
In-Hyung Yang ◽  
Jae-Eung Oh
2018 ◽  
Vol 140 ◽  
pp. 178-182 ◽  
Author(s):  
Marek Moravec ◽  
Gabriela Ižaríková ◽  
Pavol Liptai ◽  
Miroslav Badida ◽  
Anna Badidová

1997 ◽  
Vol 25 (1) ◽  
pp. 29-42 ◽  
Author(s):  
E-J. Ni ◽  
D. S. Snyder ◽  
G. F. Walton ◽  
N. E. Mallard ◽  
G. E. Barron ◽  
...  

Abstract As a general trend, vehicle sound quality has significantly improved in recent years. This is primarily due to improved body structure and powertrain design. As demand for better vehicle sound quality increases, it is important to study all possible noise sources contributing to noise, vibration, and harshness (NVH). Tire vibration has long been recognized as a source of airborne noise. Some effects of wheel design on tire noise have also been well understood for sometime. But the dynamic interaction between tire and wheel designs and its effect on vehicle NVH, although frequently observed for many years, has only recently been identified in the 200–350 Hz frequency range. Different wheels can produce perceptible differences in vehicle interior sound pressure levels in a road test. Hence, the authors have developed a process to quantify and reduce noise caused by a vibrating tire/wheel assembly. This paper discusses the general flow of the process, which begins with the identification of NVH issues on a total vehicle level. Modeling and optimization of the aluminum wheel was chosen as the focus of this project for two reasons. First, the interior sound pressure level (SPL) around 285 Hz is about 5–7 dBA higher in a vehicle equipped with aluminum wheels rather than a steel design. Second, modifying the wheel is far more economical and faster due to its simplicity of design than the complexity of either the vehicle body structure or a tire.


Author(s):  
Jae-Eun Jeong ◽  
In-Hyung Yang ◽  
Goon-Dong Park ◽  
Jae-Eung Oh

Author(s):  
Anja Kurz ◽  
Maren Zanzinger ◽  
Rudolf Hagen ◽  
Kristen Rak

Abstract Objective Cochlear implantation has become a well-accepted treatment option for people with single-sided deafness (SSD) and has become a clinical standard in many countries. A cochlear implant (CI) is the only device which restores binaural hearing. The effect of microphone directionality (MD) settings has been investigated in other CI indication groups, but its impact on speech perception in noise has not been established in CI users with SSD. The focus of this investigation was, therefore, to assess binaural hearing effects using different MD settings in CI users with SSD. Methods Twenty-nine experienced CI users with SSD were recruited to determine speech reception thresholds with varying target and noise sources to define binaural effects (head shadow, squelch, summation, and spatial release from masking), sound localization, and sound quality using the SSQ12 and HISQUI19 questionnaires. Outcome measures included the MD settings “natural”, “adaptive”, and “omnidirectional”. Results The 29 participants involved in the study were divided into two groups: 11 SONNET users and 18 OPUS 2/RONDO users. In both groups, a significant head shadow effect of 7.4–9.2 dB was achieved with the CI. The MD setting “adaptive” provided a significant head shadow effect of 9.2 dB, a squelch effect of 0.9 dB, and spatial release from masking of 7.6 dB in the SONNET group. No significant summation effect could be determined in either group with CI. Outcomes with the omnidirectional setting were not significantly different between groups. For both groups, localization improved significantly when the CI was activated and was best when the omnidirectional setting was used. The groups’ sound quality scores did not significantly differ. Conclusions Adaptive directional microphone settings improve speech perception and binaural hearing abilities in CI users with SSD. Binaural effect measures are valuable to quantify the benefit of CI use, especially in this indication group.


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