• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.25-32
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• 2017

Besides their effect on the f0 contour of the following vowel, Korean stops are undergoing a sound change in which a partial or complete consonantal merger on voice onset time (VOT) is taking place between aspirated and lax stops. Many previous studies on sound change have mainly focused on group-normative effects, that is, effects that are representative of the population as a whole. Few systematic quantitative studies of change in adult individuals have been carried out. The current study examines whether the sound change holds for individual speakers. It focuses on inter-speaker and intra-speaker variability on sound change in contemporary Korean. Speech data were collected for thirteen Seoul Korean speakers studying abroad in America. In order to minimize the possible effects of speech production, socio-phonetic factors such as age, gender, dialect, speech rate, and L2 exposure period were controlled when recruiting participants. The results showed that, for nine out of thirteen speakers, the consonantal merger is taking place between the aspirated and lax stop in terms of VOT. There were also intra-speaker variations on the merger in three aspects: First, is the consonantal (VOT) merger between the two stops is in progress or not? Second, are VOTs for aspirated stops getting shorter or not (i.e., the aspirated-shortening process)? Third, are VOTs for lax stops getting longer or not (i.e., the lax-lengthening process)? The results of remarkable inter-speaker and intra-speaker variability indicate a synchronous speech sound change of the stop system in contemporary Korean. Some speakers are early adopters or active propagators of sound change whereas others are not. Further study is necessary to see whether the inter-speaker differences exceed intra-speaker differences in sound change.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.339-347
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• 2014

Floor impact sound in high-rise apartment building became one of social problems. A lot of civil complaints on floor impact sound occur continuously and the number of disputes between neighbors in small and aged apartment buildings is increasing. Interests on heavy-weight impact sound pressure level measurement and evaluation method is increased. Previous study reported that heavy-weight impact sound level was changed by the sound field condition of receiving reverberation chamber. In this study, heavy-weight impact sound pressure level change by the receiving sound field condition was measured in standard test facility and mock-up test room. These two experimental conditions were designed to simulate averaged living room of common apartment units. By the change of sound absorption power in receiving room, heavy-weight impact sound pressure level in most of frequency bands were changed in standard test facility and mock-up room. Normalized maximum sound pressure level regulated in ISO 16032 showed wider range of heavy/soft impact sound pressure level. Heavy/soft impact sound pressure level change was became smaller by the application of standardized maximum sound pressure level and ISO/CD 10140-3 Amd 2 method. In the case of standardized maximum sound pressure level, absolute sound pressure level changed. From these results, receiving sound field correction method regulated in ISO/CD 10140-3 Amd 2 is needed for the precision measurement and evaluation of heavy-weight impact sound.

• The Journal of the Acoustical Society of Korea
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• v.27 no.4
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• pp.178-182
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• 2008

In measurements of the vibration of structures underwater with a laser Doppler vibrometer, the surface vibration is measured by means of detecting the phase change of the laser beam due to the structural vibration. The laser beam passes through the sound field radiated from the vibrating structures underwater. It experiences an additional phase change due to the change in refractive index in the radiated sound field. This phase change due to the sound field may cause the error in surface vibration measurements. In this paper, this phase change due to the radiated sound filed has been analyzed. The numerical simulation has been peformed to evaluate the phase change in sound field radiated from an infinite cylindrical structure vibrating underwater.

• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.9-17
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• 2021

Voice onset time (VOT) is known to be a primary acoustic cue that differentiates voiced from voiceless stops in the world's languages. While much attention has been given to the sound change of Korean stops, little attention has been given to that of English stops. This study examines VOT of stop consonants as produced by English speakers in comparison to Korean speakers to see whether there is any VOT change for English stops and how the effects of stop, place, gender, and individual on VOT differ cross-linguistically. A total of 24 native speakers (11 Americans and 13 Koreans) participated in this experiment. The results showed that, for Korean, the VOT merger of lax and aspirated stops was replicated, and, for English, voiced stops became initially devoiced and voiceless stops became heavily aspirated. English voiceless stops became longer in VOT than Korean counterparts. The results suggest that, similar to Korean stops, English stops may also undergo a sound change. Since it is the first study to be revealed, more convincing evidence is necessary.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.23-29
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• 2016

The present study tested if individual speakers showing great sound change in segments (i.e., vowels and fricatives) also had innovative changing patterns in suprasegmental properties (i.e., lexical pitch accents) in Kyungsang Korean. The acoustic analysis at a group level first confirmed the presence of group level differences in distinguishing /ɨ-ʌ/ and /s-s'/ both of which had different phonemic distinction from Seoul Korean. Younger speakers had more innovative segmental change than older speakers, and even within the younger generation, female speakers produced more innovative phonetic variants than male speakers. Regarding the individual observation within the younger group, the younger speakers with large acoustic distinction in vowels and fricatives also showed acoustically less distinct accent patterns, indicating the innovative sound change pattern consistent across segment and suprasegmental properties. The group and individual observations suggested that linguistic innovators introduced new phonetic variants with consistent degree of changing pattern between segment and suprasegmental properties.

• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.53-59
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• 2017

The present study examined if individual listeners' perceptual variations were associated with their cognitive characteristics indexed by the Autistic Spectrum Quotient (AQ). This study first investigated the perception of the lexical pitch accent contrast in the Kyungsang Korean currently undergoing a sound change, and then tested if listeners' perceptual variations were correlated with their AQ scores. Eighteen Kyungsang listeners in their 20s participated in the perception experiment where they identified two contrastive accent words for auditory stimuli systematically varying F0 scaling and timing properties; the participants then completed the AQ questionnaire. In the results, the acoustic parameters reporting reduced phonetic differences across accent contrasts for younger Kyungsang generation played a reliable role in perceiving the HH word from HL, suggesting the discrepancy between the perception and the production in the context of sound change. This study also observed that individuals' perceptual variations were negatively correlated with their AQ sub scores. The present findings suggested that the sound change might appear differently between production and perception with a different time course, and deviant percepts could be explained by individuals' cognitive measure.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.393-396
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• 2022

Recently, rapid climate change has had a significant impact on the ecosystem of honeybees. In addition, the problem of Vespa Hornets invasion of colonies has a fatal impact on the bee ecosystem, independent of climate change. Especially in late summer. This study relates to a method for preventing Vespa Hornets attack. In this study, we developed a Vespa Hornets sound detection device was developed by collecting and analyzing the sound of a Vespa Hornets and applying IoT technology. The developed device detects the sound of a Vespa Hornets when Vespa Hornets appears around the hive of the bees and sends a signal to automatically close the door of the beehive. The device that receives the signal drives the motor that controls the honeycomb door to close the beehive door. The Vespa Hornets sound detection device operates until no Vespa Hornets sound is detected. The system developed by us is expected to be installed in the beehives of actual beekeeping farms to dramatically reduce the damage caused by by Vespa Hornets.

• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.193-203
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• 1994

The author performed this study for investigation of the magnitude of mandibular positional change caused by joint sound during mandibular opening and closing movement. There have been many studies stated mandibular border movement or other functional movement, and there also have been many studies reported clicking sound related to mandibular movement speed, trajectory and clinicl course of temporomandibular disorders(TMDs), but there have not been so many studies stated spatial mandibular position accompanied by joint sound. For this study 46 TM joint from the patients with TMDs were used and they were compared by character and occuring phase of the joint sound. Synchronized data which were amplitude and frequency of joint sound and amount of mandibular positional change were collected through sonopak and BioEGN rotate of Biopak system, respectively. Mandibular position was analyzed for translational and rotational movement change between before and after joint sound. The obtained data were processed with SAS program and summary of this paper were as follows : 1. Mean value of the amount of translational movement in whole joints were 6.0mm in vertical direction, 3.3mm in anteroposterior direction and 0.8mm in lateral direction between before and after joint sound. 2. Mean value of the amount of translational movement in clicking joinnts showed slightly increased tendency than in popping joints. 3. The amount of mandibular change in translational movement during closing phase were more than during opening phase. 4. The amount of mandibular rotational change in whole joints were $1.1^{\circ}$, 1.0mm in frontal plane and $0.9^{\circ}$, and 0.8mm in horizontal plane. 5. The amount of rotational movement were more in clicking joints than in popping joints and were more during closing phase than during opening phase, but statistically significance were showed only in frontal plane.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.11 s.176
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• pp.59-63
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• 2005

Since human listening is very sensitive when the sound hit him, the subjective index of sound quality is required. Therefore, at each situation of sound evaluation its composed with the sound quality factor. But, when substituting the level of one frequency band we could not see the tendency of substitution at whole frequency band during the sound quality evaluation. In this study a design of experiment is used. The frequency domain is divided into an equally 12 parts and each level of domain whether is given increase or decrease due to the change of frequency band based on 'sharp' and 'annoy' of the sound quality is analyzed. By using the design of experiment the number of test is reduce very effectively by the number of experiment and each band the main effect will be as a solution. The case of sound quality for 'sharp' and 'annoy' at each band, the change of band (increase or decrease of sound pressure or keep maintain) which will be the most effects on the characteristics of sound quality can be identify and this will be able to us to select the objective frequency band. Through these obtained results the physical changes of level at arbitrary frequency domain sensitivity can be adapted.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.3 s.96
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• pp.320-328
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• 2005

Last target of architectural acoustics is that people wish to convey voice effectively from the space adaptively in use purpose in building. But, how exactly through space sound (sound source) that wish to deliver from indoor can be passed method to do quantification and evaluate quantity of sound by method to serve indoor architectural acoustics estimation summer period and methods to estimate definition propose. This Study searches special quality of sound source about MLS signal that is occurred short-answer sound source (pistol sound source) and nondirectional speaker among indoor sound estimation method, and measure and analyzed reverberation time (RT60), definition (C80, D50) by regulation of each ISO 3382 in age place (classroom, hall, gymnasium). Analysis result and sound factor among could know that d of two sound sources converges in measurement error extent about reverberation time (RT60) of analysis incidental and sound factors and value shows change irregularly about sound factor of D50, C80, pistol sound source judged there is problem. Also, could know that problem is happened in deflection except reverberation time is in deflection analysis with wave that measure each in fixed distance in branch. Finally, when differ size of sound source and measure about change of sound pressure level in case measure sound pressure level giving difference about 10 dB, sound factor could know that there is no different effect.