• 말소리와 음성과학
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• 제1권3호
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• pp.19-28
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• 2009

This paper reports experimental findings about the duration feature of the acoustic components of English stops in Korean speakers' voicing perception. In our experiment, 35 participants discriminated between recorded stimuli and digitally transformed stimuli with different duration features from the original stimuli. 72 sets of paired stimuli are generated to test the effects of the duration feature in various phonetic contexts. The result of our experiment is a complicated cross-tabulation with 540 cells defined by five categorical independent variables plus one response variable. To find a meaningful generalization out of this complex frequency table, we ran logit log-linear regression analyses. Surprisingly, we have found that there is no single effect of the duration feature in all phonetic contexts on Korean speakers' perception of the voicing contrasts of English stops. Instead, the logit log-linear analyses reveal that there are interaction effects among phonetic contexts (=C), the places of articulation of stops (=P), and the voicing contrast (=V), and among duration (=T), phonetic contexts, and the places of articulation. To put it in mathematical terms, the distribution of the data can be explained by a simple log-linear equation, logF=${\mu}+{\lambda}CPV+{\lambda}TCP$.

• 음성과학
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• 제9권3호
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• pp.223-235
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• 2002

Unlike Seoul dialect, in the Busan dialect, /ㅅ/ and /ㅆ/ are phonemically non-distinctive and realization of tensing is non-productive, on the other hand, that of voicing is productive. In order to discover causes of such characteristics in Busan dialect, this paper firstly compared acoustic characteristics of Seoul dialect with those of Busan dialect on fricative /ㅅ/ and /ㅆ/. The result showed that Busan dialect has much shorter length of friction and aspiration intervals of word initial and word-medial position than Seoul dialect. I expect that these results are important keys to discover causes of the following characteristics of Busan-dialect - non-distinction, non-productivity of tensing, and productivity of voicing - on Fricative /ㅅ/ and /ㅆ/.

• 음성과학
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• 제7권3호
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• pp.35-51
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• 2000

The goal of this paper is to examine how Case Drop (the drop of the case markers) correlates with the prosodic structure in Korean. On the assumption that intervocalic Lenis Stop Voicing (LSV) applies within the domain of the Accentual Phrase (AP), voicing analyses are performed on intervocalic lenis stop consonants before and after Case Drop. A statistical analysis reveals that the drop of the nominative and accusative case markers significantly alter the AP structure. Pitch values will then be extracted to verify that such changes in the AP structure conform to the pitch properties proposed for the AP (Jun 1993, 1998). The results show that the AP structure suggested by LSV does not always coincide with that imposed by the pitch properties.

• 음성과학
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• 제13권3호
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• pp.19-33
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• 2006

This study explores whether Russian, known to have a process of syllable-final devoicing, reveals differences in vowel duration as a function of the underlying voicing of the coda stop. This paper also examines whether non-native speakers of Russian and English learn typical L2 values in vowel duration. The results indicate that vowels in Russian have a slightly longer mean duration before a voiced stop than before a voiceless stop (a mean difference of 9.52 ms), but in most cases the differences did not exhibit statistical significance. In English the mean difference was 60.05 ms, and the differences were in most cases statistically significant. All native Russian speakers of English produced larger absolute differences in vowel duration for English than for Russian, and all native English speakers of Russian produced smaller absolute differences for Russian than for English. More experienced learners seemed to achieve more native-like values of vowel duration than less experienced learners did, suggesting that learning occurs gradually as the learners gain more experience with the L2.

• 말소리와 음성과학
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• 제15권4호
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• pp.11-16
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• 2023

The present study examines how a cognitive attention affects Korean learners of English (L2) in perceiving the English stop voicing distinction (/d/-/t/). This study tested the effect of attentional distractor on primary and non-primary acoustic cues, focusing on the role of Voice Onset Time (VOT) and fundamental frequency (F0). Using the dual-task paradigm, 28 Korean adult learners of English participated in the stop identification task carried with (distractor) and without (no-distractor) arithmetic calculation. Results showed that when distracted, Korean learners' sensitivity to VOT decreased as priorly reported with native English speakers. Furthermore, as F0 is a primary cue for a L1 Korean stop laryngeal contrast, its role in L2 English voicing distinction was also affected by a distractor, without compensating for the reduced VOT sensitivity. These findings suggest that flexible use of multiple cues in L1 is not necessarily beneficial for L2 phonological processing when coping with a adverse listening condition.

• 한국음향학회지
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• 제20권3호
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• pp.56-62
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• 2001

본 논문에서는 손실이 발생하는 상황에서 높은 인식률을 유지하기 위해서 손실 데이터 이론을 음성 인식기에 적용하였다 손실 데이터 이론은 일반적으로 이용되는 통계적 정합 방법인 은닉 마코프 모델 (HMM: hidden Markov model) 중 연속 Gaussian확률 밀도 함수를 이용하여 음성 특징들의 출력 확률을 나타내는 경우에 쉽게 적용할 수 있다는 장점을 갖고 있다. 손실 데이터 이론의 방법 중 계산량이 적고 인식기에 적용이 쉬운 주변화(marginalization)방법을 사용하였으며 특징 벡터의 특정 차수나 시간열의 손실 검출 방법은 음성 신호의 에너지와 주위 배경 잡음의 에너지의 차이가 임계치보다 작게 되는 부분을 찾는 주파수 차감 방법을 이용하였다. 본 논문에서 제안한 손실 영역의 신뢰도 평가는 분석 구간이 모음일 확률을 계산해서 비교적 잉여 정보가 많이 포함된 모음화된 구간의 손실만을 처리하도록 하였다. 제안한 방법을 사용하여 여러 잡음 환경에 대해서 기존의 손실 데이터 처리 방법만을 사용한 경우보다 452 단어의 화자독립 단어 인식 실험을 수행한 결과 오류율측면에서 평균적으로 약 12％의 성능 향상을 얻을 수 있었다.

• 말소리와 음성과학
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• 제5권4호
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• pp.129-136
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• 2013

This study investigated how acoustic characteristics (i.e., duration, F1, F2) of English high front vowels /i, ɪ/ are modulated by boundary- and prominence-induced strengthening in native vs. non-native (Korean) speech production. The study also examined how the durational difference in vowels due to the voicing of a following consonant (i.e., voiced vs. voiceless) is modified by prosodic strengthening in two different (native vs. non-native) speaker groups. Five native speakers of Canadian English and eight Korean learners of English (intermediate-advanced level) produced 8 minimal pairs with the CVC sequence (e.g., 'beat'-'bit') in varying prosodic contexts. Native speakers distinguished the two vowels in terms of duration, F1, and F2, whereas non-native speakers only showed durational differences. The two groups were similar in that they maximally distinguished the two vowels when the vowels were accented (F2, duration), while neither group showed boundary-induced strengthening in any of the three measurements. The durational differences due to the voicing of the following consonant were also maximized when accented. The results are discussed further in terms of phonetics-prosody interface in L2 production.

• 음성과학
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• 제12권4호
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• pp.113-128
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• 2005

The underlying premise of this study was that L1 production is easily transferred into L2 production. In neutral intonation, there is a consonant-tone correlation in Korean: High tone patterns are correlated with voiceless aspirated and tense consonants and Low-High tone patterns are correlated with lax or other voiced consonants. The purpose of this study was to see whether the correlation in Korean (L1) is transferred into English (L2) production and whether the degree of transfer differs depending on the degree of proficiency. Eight Korean speakers and two American speakers participated in the experiment. F0 contours of words and sentences were collected and analyzed. The results of the present study showed that there is a strong correlation between voicing and tone in L2 utterances. When utterance-initial consonant types were voiceless, the word or the sentence began with the H pattern; otherwise it had the LH pattern. The degree of interference differed depending on the degree of proficiency: less proficient speakers showed a stronger correlation in terms of the magnitude (Hz) and size (ms) of the effects on F0. The results indicate that the consonant-tone correlation in L1 is strongly transferred into L2 production and the correlation transfer can be one of the actual aspects that cause L2 speakers to produce deviant L2 accents and intonation.

• 말소리와 음성과학
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• 제15권3호
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• pp.9-16
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• 2023

The current study investigated the influence of age of L2 acquisition (AOA) and length of residence (LOR) in the L2 setting country on the production of voicing-conditioned vowel duration and spectral qualities in English by Korean learners. The primary aim was to explore the ways in which the language-specific phonetic features are acquired by the age of onset and L2 experience. Analyses of the archived corpus data produced by 45 native speakers of Korean showed that, regardless of AOA or LOR, absolute vowel duration was used as a salient correlate of voicing contrast in English for Korean learners. The accuracy of relative vowel duration was influenced more by onset age than by L2 experience, suggesting that being exposed to English at an early age may benefit the acquisition of temporal dimension. On the other hand, the spectral characteristics of English vowels were more consistently influenced by L2 experience, indicating that immersive experience in the L2 speaking environment are likely to improve the accurate production of vowel quality. The distinct influence of the onset age and L2 experience on the specific phonetic cues in L2 vowel production provides insight into the intricate relationship between the two factors on the manifestation of L2 phonological knowledge.

• 대한후두음성언어의학회지
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• 제7권1호
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• pp.39-42
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• 1996

본 연구는 농자의 음성의 주파수 변동율(jitter) 진폭 변동율(shimmer)을 4가지 발성 상황에서 분석하였다. 32명의 남자 피험자와 27명의 여자 피험자가 자진하여 실험에 참여하였다. 남자 피험자의 연령 범위는 6세-18세, 여자 피험자의 연령 범위는 8세-21세였다. 피험자들은 선천적인 농이거나 언어발달 이전에 농자가 되었다 4가지의 발성 상황이란 /a/를 연장발성 하는 것, 수를 1에서 10까지 헤아리는 것, '산책'이라는 문단을 낭독하는 것, 대화 시 발성 등을 말한다. 실험에 사용된 기구는 CSL Visi-Pitch Model 6095(Kay Elemetrics Corp.)이었다. 주파수 변동율 평균치와 진폭 변동을 평균치 모두 보고된 역치(표준 자료)보다 높았다 또한 본 연구는 주파수 변동율과 진폭 변동율이 성별과 발성상황에 따라 변하는지 규정하기 위하여, 2가지의 2원 변량분석 (2-factor ANOVA)을 실시하였다. 결과는 다음과 같다. 첫째 성별은 주파수 변동율에는 영향을 미치지 않지만 진폭 변동율에는 영향을 미쳤다. 남자 피험자의 진폭 변동율이 여자 피험자의 진폭 변동율에 비해 높았다. 둘째, 발성상황은 주파수 변동율과 진폭 변동율 모두에 영향을 주었다. /a/ 연장발성과 낭독에서는 수 헤아리기와 대화상황에서보다 주파수 변동율이 낮았다. /a/ 연장발성에서는 나머지 상황에 비하여 진폭 변동율이 낮았다. 마지막으로, 성별과 발성상황간의 상호작용(interaction)은 발견되지 않았다.