• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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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.

• 말소리와 음성과학
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• 제12권4호
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• pp.9-17
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• 2020

Changes in the first language (L1) sound system as a result of acquiring a second language (L2) (i.e., phonetic drift) have received considerable attention from a variety of speakers, settings, and environments. Less attention has been given to phonetic drift in adult speakers' L2 learning as their length of residence in America (LOR) increases. This study examines the effects of LOR on voice onset time (VOT) in L1 Korean stops. Three different groups of Korean adult learners of L2 English were compared to assess how malleable their L1 representations are in terms of LOR and whether there is any relationship between L1 change and L2 acquisition. The results showed that the effect of LOR was linguistically unimportant in the production of Korean stops. However, VOT merger as evidence of sound change in Korean stops were robust in the speech production of most of the female speakers across the groups. The results suggest that L2 English may not be the primary cause of L1 sound change. For generalizability, further study is necessary to see whether other acoustic cues show a similar pattern.

• 한국전문물리치료학회지
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• 제15권3호
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• pp.35-43
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• 2008

The purpose of this study was to compare spatio-temporal parameters during walking between patients with idiopathic Parkinson's disease and a control group matched for age, height, and weight. Thirty-three subjects were included in this study. Fifteen normal subjects (age, $63.3{\pm}5.8$ yrs; height, $164.1{\pm}8.7$ cm; weight, $60.7{\pm}17.5$ kg) and eighteen patients (age, $64.0{\pm}7.7$ yrs; height, $164.7{\pm}7.3$ cm; weight, $63.6{\pm}7.7$ kg) participated in the study. The Vicon 512 Motion analysis system was used for gait analysis in each group during walking, with and without an obstacle. The measured spatio-temporal parameters were cadence, walking speed, stride time, step time, single limb support time, double limb support time, stride length, and step length. Results in stride length and step length, when walking without an obstacle, showed a significantly greater decrease in the patient group compared to the control group. During walking with an obstacle, the patient group showed a significantly greater decrease in the step length as compared to the control group. For the control group, there were significant decreases in parameters of cadence and walking speed and increases in parameters of stride time, step time, and single limb support time when walking with an obstacle. The patient group had lower cadence and walking speed and higher stride time, step time, and single limb support time during walking with an obstacle than in walking without an obstacle. These results suggest that patients with Parkinson's disease who walk over an obstacle can decrease cadence, stride length, and step length. Further study is needed, performed with more obstacles and combined with other external cues, such as visual or acoustic guides.

• 말소리와 음성과학
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• 제7권3호
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• pp.13-26
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• 2015

Speech production studies have suggested that bilinguals who are L2-dominant are the most likely to suppress the influence of the first language (L1) on the second language (L2). The voice onset times (VOTs) and fundamental frequencies (f0s) of monolingual and bilingual speakers of English and Korean were examined to address the question whether cross language influences occur particularly in L2 predominant bilinguals and to compare their outcomes with those of L2 proficient bilinguals and monolinguals. A total of 28 speakers participated in this experiment and they produced English and Korean stops in the carrier sentence. In English, for voiceless aspirated and unaspirated stops, L2 predominant bilingual speakers produced VOTs that were significantly shorter than those of monolingual English speakers. The outcome was analogous in Korean speech. For aspirated and lax stops, they produced shorter Korean VOTs than monolingual speakers. The results of f0s were slightly different from those of VOTs. In English, L2 predominant bilinguals produced f0s that were not significantly different from those of monolingual English speakers. In Korean, however, they produced f0s that were significantly different from those of monolingual Korean speakers. Taken VOT and f0 into consideration together, the overall results suggest that, although they tend to show a corresponding pattern of monolinguals, L2 predominant bilinguals had cross language phonetic influences between L1 and L2, similar to L2 proficient bilinguals. Between the two acoustic cues, f0 seemed to be a more reliable cue than VOT to examine the influences.

• Journal of Audiology & Otology
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• 제24권3호
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• pp.133-139
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• 2020

Background and Objectives: The Gaps-In-Noise (GIN) test is a clinically effective measure of the integrity of the central auditory nervous system. The GIN procedure can be applied to a pediatric population above 7 years of age. The present study conducted the GIN test to compare the abilities of auditory temporal resolution among typically developing children, children with speech sound disorder (SSD), and children with cognitive difficulty (CD). Subjects and Methods: Children aged 8 to 11 years-(total n=30) participated in this study. There were 10 children in each of the following three groups: typically developing children, children with SSD, and children with CD. The Urimal Test of Articulation and Phonology was conducted as a clinical assessment of the children's articulation and phonology. The Korean version of the Wechsler Intelligence Scale for Children-III (K-WISC-III) was administered as a screening test for general cognitive function. According to the procedure of Musiek, the pre-recorded stimuli of the GIN test were presented at 50 dB SL. The results were scored by the approximated threshold and the overall percent correct score (%). Results: All the typically developing children had normal auditory temporal resolution based on the clinical cutoff criteria of the GIN test. The children with SSD or CD had significantly reduced gap detection performance compared to age-matched typically developing children. The children's intelligence score measured by the K-WISC-III test explained 37% of the variance in the percent-correct score. Conclusions: Children with SSD or CD exhibited poorer ability to resolve rapid temporal acoustic cues over time compared to the age-matched typically developing children. The ability to detect a brief temporal gap embedded in a stimulus may be related to the general cognitive ability or phonological processing.

• 대한청각학회지
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• 제24권3호
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• pp.133-139
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• 2020

Background and Objectives: The Gaps-In-Noise (GIN) test is a clinically effective measure of the integrity of the central auditory nervous system. The GIN procedure can be applied to a pediatric population above 7 years of age. The present study conducted the GIN test to compare the abilities of auditory temporal resolution among typically developing children, children with speech sound disorder (SSD), and children with cognitive difficulty (CD). Subjects and Methods: Children aged 8 to 11 years-(total n=30) participated in this study. There were 10 children in each of the following three groups: typically developing children, children with SSD, and children with CD. The Urimal Test of Articulation and Phonology was conducted as a clinical assessment of the children's articulation and phonology. The Korean version of the Wechsler Intelligence Scale for Children-III (K-WISC-III) was administered as a screening test for general cognitive function. According to the procedure of Musiek, the pre-recorded stimuli of the GIN test were presented at 50 dB SL. The results were scored by the approximated threshold and the overall percent correct score (%). Results: All the typically developing children had normal auditory temporal resolution based on the clinical cutoff criteria of the GIN test. The children with SSD or CD had significantly reduced gap detection performance compared to age-matched typically developing children. The children's intelligence score measured by the K-WISC-III test explained 37% of the variance in the percent-correct score. Conclusions: Children with SSD or CD exhibited poorer ability to resolve rapid temporal acoustic cues over time compared to the age-matched typically developing children. The ability to detect a brief temporal gap embedded in a stimulus may be related to the general cognitive ability or phonological processing.

• 말소리와 음성과학
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• 제15권4호
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• pp.17-26
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• 2023

이 연구는 베트남인 성인 학습자들이 학습 단계별로 한국어 어두 초성 장애음을 어떻게 지각하는지 밝히고, 지각 훈련을 통해 오류가 교정될 수 있는지를 밝히는 것을 목적으로 한다. 이를 위해 베트남인 초급, 중급, 고급 학습자 105명을 대상으로 한국어 초성 장애음에 대한 지각 훈련을 실시하였다. 훈련 자료는 원어민 음성으로 녹음한 자연 자극으로 한국어의 최소대립쌍을 적극적으로 활용하여 제작하였다. 실험 집단에 속한 학습자들은 약 2주간에 걸쳐 20-40분의 자기주도적 지각 훈련을 5회 수행했고, 통제 집단에 속한 학습자들은 사전 테스트와 사후 테스트에만 참여하였다. 실험 결과 훈련 전에 잘 구분되지 않았던 음들에 대한 지각이 많이 개선되었고, 초급뿐만 아니라 고급 집단의 학습자들도 끝까지 교정이 잘 되지 않았던 음에 대한 효과를 보았다. 이 연구에서는 대규모의 지각 훈련을 통해 베트남인 학습자들이 한국어의 서로 다른 음을 구별하는 적절한 음향 단서를 학습하는 데 지각 훈련이 중요한 역할을 할 수 있음을 확인하였다.

• 말소리와 음성과학
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• 제15권1호
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• pp.35-45
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• 2023

일본어의 전통적인 어두 폐쇄음은 파열 전에 성대 진동을 동반하는 유성음과 파열 후에 약간의 기음을 동반하는 무성음으로 이분된다. 한편 도호쿠지방의 유성음은 어느 세대나 파열 전에 성대 진동을 동반하지 않고 무성화한 유성음으로 실현되어 다른 지역과 대조를 이룬다. 무성화한 유성음은 voice onset time(VOT)이 양값으로 나타나고 그러면 기존의 무성음의 VOT와 충돌하게 되어 카테고리 구별에 영향을 미치게 된다. 이에 대해 도호쿠지방의 화자는 생성 시에 다른 지역과는 달리 폐쇄음 구별에 후속 모음의 fundamental frequency(F0)를 적극적으로 사용하는 것이 여러 연구에 의해 확인되었다. 본 연구는 인지면에서도 F0가 폐쇄음 구별에 중요한 역할을 하고 있는지를 밝히기 위해 VOT와 함께 검토한 것이다. VOT와 F0를 재합성한 자극음을 사용하여 도호쿠지방 청자를 대상으로 조건을 달리한 여러 개의 지각실험을 실시하였다. 결과에서는 무의미어의 경우 지역차(도호쿠 지방 vs.주부 지방)는 유의하지 않았으나 유의미어에서는 어휘에 따라 F0 사용에 유의한 차이가 있었으며 이러한 차이는 F0를 적극적으로 사용하는 몇몇의 청자들에게서 기인하는 것으로 밝혀졌다. 논의에서는 이들이 혁신 청자들로 여겨지며 이들을 중심으로 폐쇄음 지각에 F0 역할이 일반화되고 지각특성으로서 F0가 확립될 가능성에 대해 추론해 보았다.