• 음성과학
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• 제7권2호
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• pp.139-155
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• 2000

The aim of this research is to investigate acoustic characteristics of three different types of Korean Stops-plain, tensed, and aspirated-, and employ these as a base to determine which one(s) can be used as perceptual cues. In this paper, we have examined acoustic characteristics of Korean Stops, especially voice onset time(VOT), closure duration(CD), degree of pitch of following vowels and differences in the intensity of the Stops build-up after the onset of voicing. From the above characteristics, differences can be made between word-initial and word-medial positions. That is to say, in word-initial position, the three Korean Stops are distinguished by VOT and pitch, whereas in word-medial by CD, VOT and pitch. However, the acoustic characteristics do not have the same value as perceptual cues. In both word-initial, and medial positions, the immediately following vowels play the most important role in perceiving Korean Stops. And in case of word'-medial positions,. CD and VOT also play important perceptual roles. In order to have a more fine-grained distinction among Korean Stops, we think future research should be done to investigate which factor(s) of the following vowels is/are the most determinative perceptual cue(s). However, based on our investigation, we may conclude that it is highly plausible that pitch can be one of the most important perceptual cues when distinguishing the three Korean Stops.

• 말소리와 음성과학
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• 제14권4호
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• pp.19-24
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• 2022

This study examined which acoustic cue(s) that Korean learners of English give weight to in perceiving English lexical stress. We manipulated segmental and suprasegmental cues in 5 steps in the first and second syllables of an English stress minimal pair "object". A total of 27 subjects (14 native speakers of English and 13 Korean L2 learners) participated in the English stress judgment task. The results revealed that native Korean listeners used the F0 and intensity cues in identifying English stress and weighted vowel quality most strongly, as native English listeners did. These results indicate that Korean learners' experience with these cues in L1 prosody can help them attend to these cues in their L2 perception. However, L2 learners' perceptual attention is not entirely predicted by their linguistic experience with specific acoustic cues in their native language.

• 음성과학
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• 제10권1호
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• pp.41-58
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• 2003

Coronal/non-coronal asymmetry refers to the typological trend wherein coronals rather than non-coronals are more likely targets in place assimilation. Although the phenomenon has been accounted for by resorting to the notion of unmarkedness in formalistic approaches to sound patterns, the examination of rules and representations cannot answer why there should be such a process in the first place. Furthermore, the motivation of coronal/non-coronal asymmetry has remained controversial to date even in the field of phonetics. The present study investigated the listeners' perception of coronal and non-coronal stops in the context of $VC_{1}C_{2}V$ after critically reviewing the three types of phonetic accounts for coronal/non-coronal asymmetry, i.e., articulatory, perceptual, and gestural overlap accounts. An experiment was conducted to test whether the phenomenon in question may occur, given the listeners' lack of perceptual ability to identify weaker place cues in VC transitions as argued by Ohala (1990), i.e., coronals have weak place cues that cause listeners' misperception. 5pliced nonsense $VC_{1}C_{2}V$ utterances were given to 20 native speakers of English and Korean. Data analysis showed that majority of the subjects reported $C_{2}\;as\;C_{1}$. More importantly, the place of articulation of C1 did not affect the listeners' identification. Compared to non-coronals, coronals did not show a significantly lower rate of correct identifications. This study challenges the view that coronal/non-coronal asymmetry is attributable to the weak place cues of coronals, providing evidence that CV cues are more perceptually salient than VC cues. While perceptual saliency account may explain the frequent occurrence of regressive assimilation across languages, it cannot be extended to coronal/non-coronal asymmetry.

• 말소리와 음성과학
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• 제12권1호
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• pp.43-50
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• 2020

This study investigated whether listeners' perceptual patterns varied according to base token selected for stimuli manipulation. Voice onset time (VOT) and fundamental frequency (F0) values were orthogonally manipulated, each in seven steps, using naturally produced words that contained a lenis (/kan/) and an aspirated (/k^han/) stop in Seoul Korean. Both native and non-native groups showed significantly higher numbers of aspirated responses for the stimuli constructed with /k^han/, evidencing the use of minor cues left in the stimuli after manipulation. For the native group the use of the VOT and F0 cues in the stop categorization did not differ depending on whether the base token included the lenis or aspirated stop, indicating that the results of previous studies remain tenable that investigated the relative importance of the acoustic cues in the native listener perception of the Korean stop contrasts by using one base token for manipulating perceptual stimuli. For the non-native group, the use patterns of the F0 cue differed as a function of base token selected. Some findings indicated that listeners used alternative cues to identify the stop contrast when major cues sound ambiguous. The use of the manipulated VOT and F0 cues by the non-native group was not native-like, suggesting that non-native listeners may have perceived the minor cues as stable in the context of the manipulated cue combinations.

• 한국어교육
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• 제28권3호
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• pp.25-51
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• 2017

This study aimed to identify the differences in pitch perception between tonal and non-tonal language listeners. A total of 60 Korean and Chinese listeners participated in the perception test. A two-syllable nonsense word /paba/ was manipulated in five steps. The pitch height or contour on the second syllable was raised or lowered. Both groups were asked to select which of the two syllables had the higher pitch. The findings showed that the majority of Korean listeners (GK) perceived decreased pitch as each peak of the syllable was lowered and perceived increased pitch as it was raised, which means the pitch height is a primary perceptual cue for GK. However, Chinese listeners (GC) perceived sensitive pitch movements as the pitch contour changed. GC's perception may presumably be affected by the L1's tone sandhi. We found it reasonable to assume that language experience has a significant effect on the cross-linguistic perceptual differences between tone and non-tonal language listeners.

• Spatial Information Research
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• 제18권3호
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• pp.23-32
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• 2010

산림영역에서 획득된 라이다데이터는 산림영역의 DTM생성, 수고 및 산림생체량 추정과 같은 산림연구에 효과적으로 이용될 수 있다. 이를 위한 핵심적인 전처리 과정으로 본 연구는 라이다데이터로부터 산림영역을 효과적으로 탐지하기 위한 방법을 개발하고자 한다. 먼저 라이다데이터로부터 산림영역으로 판단하기에 효과적인 다반사 특성, 높이값 편차 및 공간적 분포에 기반한 세 가지 인지적 단서를 제시하였다. 각 단서들에 기반하여 산림후보영역을 탐지하고, 오분류를 제거하고 경계를 정제하기 위한 이진형태학적처리를 수행하여 최종산림영역을 결정하였다. 항공영상을 이용하여 생성한 기준데이터로 검증한 결과에 따르면 세 종류 단서에 의한 방법 모두 약 90% 이상의 정확도를 보이는 것으로 평가되었다. 특히 다반사 특성에 기반한 방법이 다른 방법에 비교하여 정확도 및 단순도 측면에서 보다 좋은 방법으로 판단된다. 또한, 각각의 단서에 기반한 개별적인 결과를 조합하면 분류 정확도가 개선되는 것을 확인하였다.

• 말소리와 음성과학
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• 제3권4호
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• pp.3-11
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• 2011

This experimental study has a goal to explore the perceptual sensitivity to phonetic evidence such as duration, phrase accent, or pause in disambiguation. We argue that the realization of the intonational phrasal boundary at the meaningful grammatical boundary in structurally ambiguous sentences facilitates English native listeners to distinguish the meanings of the ambiguous sentences. Moreover, the duration of the phrase-final syllable, pitch range reset, or phrasal tones also provides listeners with important phonetic evidence in disambiguation. In our perception experiment, however, Korean English learners largely depend on the realization of pause. In the results from the perception experiment, all of the groups showed an increase in the response time from the perception of no pause to pause realization. This means that pause at the phonological phrasal boundary plays a role of facilitator to English native speakers with other prosodic cues such as duration, pitch accent, or phrasal tones, while an absolutely important cue to Korean English learners.

• 음성과학
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• 제4권1호
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• pp.47-58
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• 1998

This paper tests whether frication duration plays an important role in perceiving fricatives and affricates. In other words, whether the frication duration is an acoustic cue for distinguishing fricatives from affricates. For this purpose two types of experiments are carried out. In the first experiment two sets of stimuli are created by decreasing the frication duration of fricatives by 10ms, and in the second experiment two steps of stimuli are created by increasing the frication duration of affricates by 10 ms. The results of the present study show that frication duration is the primary acoustic cue in perceiving fricative/affricate distinction in Korean. In addition, the amplitude rise time and burst information appear to play secondary roles in perceiving the distinction by a series of perception tests.

• 한국정밀공학회지
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• 제24권1호
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• pp.101-109
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• 2007

In situations of spatio-temporal perception about visuo-auditory stimulus, researches propose optimal integration hypothesis that perceptual process is optimized to the interaction of the senses for the precision of perception. So, when the visual information considered generally dominant over any other sense is ambiguous, the information of the other sense like auditory stimulus influences the perceptual process in interaction with visual information. Thus, we performed two different experiments to certain the conditions of the interacting senses and influence of the condition. We consider the interaction of the visuo-auditory stimulation in the free space, the color of visual stimulus and sex difference of testee with normal people. In first experiment, 12 participants were asked to judge the change in the frequency of audio-visual stimulation using a visual flicker and auditory flutter stimulation in the free space. When auditory temporal cues were presented, the change in the frequency of the visual stimulation was associated with a perceived change in the frequency of the auditory stimulation as the results of the previous studies using headphone. In second experiment, 30 male and 30 female were asked to judge the change in the frequency of audio-visual stimulation using a color of visual flicker and auditory flutter stimulation. In the color condition using red and green. Both male and female testees showed same perceptual tendency. male and female testees showed same perceptual tendency however, in case of female, the standard deviation is larger than that of male. This results implies that audio-visual asymmetry effects are influenced by the cues of visual and auditory information, such as the orientation between auditory and visual stimulus, the color of visual stimulus.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2005년도 추계 학술대회 발표논문집
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• pp.189-192
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• 2005

This study investigates the asymmetry effect between acoustics and perception. The examined cues are closure duration, closure voicing, VOT, release, pre-vowel duration, post-vowel duration. Five native speakers of English and 30 Korean college students participated in the present study. The results showed that high level Korean English learners parallels native speakers in their responses, while mid and low level Korean learners are substantially different from natives.