Contrastive Focus in English: A Phonetic Study

( Cho¸ Hyesun ),( Lee¸ Chungmin ) 현대영미어문학회 2012 현대영미어문학회 추계학술대회 발표논문집 Vol.2012 No.-

Phrase positional effects on F0 peak timing in Tokyo Japanese

Cho,Hyesun 한국음성학회 2011 말소리와 음성과학 Vol.3 No.3

This paper investigates phrase positional effects on the timing of F0 (pitch) peaks in Tokyo Japanese disyllabic words with varying accent type (HL or LH) and phrase position (final or non final). The F0 peak timing was normalized by the total word duration ('normalized H timing'). The normalized H timing was significantly affected by accent type and phrase position. The H timing was later in the LH accent type than in the HL accent type, and in non final positions than in final positions. In addition, to examine the validity of the quantitative results, different models of phrase position effects were compared by measuring H timing in two approaches: normalization versus relative distance measures. For the normalization measures, the H timing was measured as the time of the F0 peak divided by the total word duration or by the duration of the tone bearing syllable. For the relative distance measures, the H timing was measured as the distance in milliseconds from the end of the word or from the end of the associated syllable. The best model was the normalization by the total word duration, rather than by the duration of the tone bearing syllable. This means that phrase positional effects on the timing of F0 peaks in Japanese disyllabic words are best modeled in terms of proportion of the total word duration.

An acoustical analysis of English post-alveolar fricatives and affricates produced by Korean and English speakers

Hyesun Cho 한국음운론학회 2017 음성·음운·형태론 연구 Vol.23 No.2

This study examines acoustic properties of English post-alveolar affricates and fricatives /ʃ, ʒ, tʃ, dʒ/ produced by Korean learners of English. Five Korean learners of English and three native speakers of North American English were recorded reading materials including /ʃ, ʒ, tʃ, dʒ/. The acoustic properties examined are the ones that are known to distinguish voicing or manner contrasts: duration (closure, frication), intensity (closure, frication), frication characteristics (center of gravity (CoG), F2 and F3 at the frication release), and preceding vowel duration. The results are mostly consistent with previous studies, showing the characteristics of Korean speakers’ production of these sounds: weaker voicing in the voiced segments (indicated by lower closure intensity, higher CoG in the voiced fricatives), more palatalization (higher F2), and less lip rounding (higher F3).

A Maximum-Entropy Grammar of Phonotactics for the TRAP-BATH Vowel Distribution

Hyesun Cho 한국영어학회 2019 영어학 Vol.19 No.1

Comparing English and Korean speakers’ word-final /rl/ clusters using dynamic time warping

Hyesun Cho 한국음성학회 2022 말소리와 음성과학 Vol.14 No.1

The English word-final /rl/ cluster poses a particular problem for Korean learners of English because it is the sequence of two sounds, /r/ and /l/, which are not contrastive in Korean. This study compared the similarity distances between English and Korean speakers’ /rl/ productions using the dynamic time warping (DTW) algorithm. The words with /rl/ (pearl, world) and without /rl/ (bird, word) were recorded by four English speakers and four Korean speakers, and compared pairwise. The F2-F1 trajectories, the acoustic correlate of velarized /l/, and F3 trajectories, the acoustic correlate of /r/, were examined. Formant analysis showed that English speakers lowered F2-F1 values toward the end of a word, unlike Korean speakers, suggesting the absence of /l/ in Korean speakers. In contrast, there was no significant difference in F3 values. Mixed-effects regression analyses of the DTW distances revealed that Korean speakers produced /r/ similarly to English speakers but failed to produce the velarized /l/ in /rl/ clusters.

Variation in vowel duration depending on voicing in American, British, and New Zealand English

Cho, Hyesun Korean Society of Speech Sciences 2016 말소리와 음성과학 Vol.8 No.3

It is well known that vowels are shorter before voiceless consonants than voiced ones in English, as in many other languages. Research has shown that the ratio of vowel durations in voiced and voiceless contexts in English is in the range of 0.6~0.8. However, little work has been done as to whether the ratio of vowel durations varies depending on English variety. In the production experiment in this paper, seven speakers from three varieties of English, New Zealand, British, and American English, read 30 pairs of (C)VC monosyllabic words which differ in coda voicing (e.g. beat-bead). Vowel height, phonemic vowel length, and consonant manner were varied as well. As expected, vowel-shortening effects were found in all varieties: vowels were shorter before voiceless than before voiced codas. Overall vowel duration was the longest in American English and the shortest in New Zealand (NZ) English. In particular, vowel duration before voiceless codas is the shortest in New Zealand English, indicating the most radical degree of shortening in this variety. As a result, the ratio of vowel durations in varying voicing contexts is the lowest in NZ English, while American and British English do not show a significant difference each other. In addition, consonant closure duration was examined. Whereas NZ speakers show the shortest vowel duration before a voiceless coda, their voiceless consonants have the longest closure duration, which suggest an inverse relationship between vowel duration and closure duration.

An analysis of velar fronting in child phonology based on a longitudinal corpus study

Hyesun Cho 한국음운론학회 2014 음성·음운·형태론 연구 Vol.20 No.2

Velar fronting is a well-known phenomenon in child phonology where velars in prosodically strong position are produced as coronals, due to child’s articulatory limitations. Velar fronting is one of the unnatural phonological processes that are observed only in child, not in any known adult system. Velar fronting in one child is closely investigated through a longitudinal study using the CHILDES corpus. It turns out that the acquisition of velar production is achieved during a period of four months, yielding an S-shaped developmental curve. The result of the longitudinal study supports a view that in phonological acquisition, constraint demotion does not take place immediately but gradually as the Gradual Learning Algorithm (GLA) predicts. Assuming that velar fronting arises from the gap between perception and production in child, an Optimality-Theoretic analysis is provided, based on the framework in Pater (2004). Finally, a learning simulation is conducted using the GLA with the proposed constraint schema, fed by the real-life corpus data. The results show how ranking values of relevant constraints change over time in a child.

Production of pre-fortis clipping in English by Korean and English speakers

Hyesun Cho 한국음운론학회 2015 음성·음운·형태론 연구 Vol.21 No.1

The term pre-fortis clipping refers to the phenomenon in English of vowels being shorter before voiceless obstruents than before voiced ones. This paper examines whether ratios of duration for vowels before voiceless versus voiced obstruents are affected by speakers’ L1 and segmental properties such as consonantal manner of articulation, vowel height, and phonemic vowel length. Nine Korean speakers and four native speakers of English were recorded reading 30 minimal pairs consisting of English monosyllabic CVC words differing in coda voicing. The mean ratio of duration for vowels preceding voiceless and voiced obstruents respectively was greater for Korean speakers than for English speakers, but mixed-effects model analyses with speaker and item random effects indicate that the effect of L1 was not significant, though there was greater variation for Korean speakers than for English speakers. The ratio of vowel duration significantly differs between Korean and English speakers only before fricatives. Vowels before voiced fricatives are not sufficiently long for Korean speakers as compared to English speakers. It is suggested that, due to their lack of experience with released fricatives, Korean speakers fail to vary vowel durations sufficiently depending on the consonant manner, before stops and fricatives.

Effects of tonal distance and speech rate in the phonetic realization of Kinande H tones

Hyesun Cho 한국음운론학회 2013 음성·음운·형태론 연구 Vol.19 No.3

The effects of time pressure in the realization of the fall and the rise between H tones in Kinande are examined, through a production study of one Kinande speaker. Phonetic realization of tonal languages such as Kinande is relatively less studied, though their phonological patterns have been more studied. Two types of time pressure of different nature are tested: tonal distance (phonological) and speech rate (phonetic). For the former, the number of syllables between two H tones is varied from zero to three. For the latter, speech rate is varied among fast, normal, and slow rates. The two types of time pressure showed similar effects in some respects, e.g., reduction in pitch magnitude under time pressure, relatively consistent slope of the fall. There were also differences in the effects of two types of pressure: the slope of the rise becomes steeper in closer tonal distance, but it becomes shallower in faster speech. Overall, alignment is less affected than pitch magnitude, under both types of time pressure. This suggests that in a tonal language such as Kinande, where tones are contrastive, tonal alignment is important to maintain than pitch magnitude.

Variation in vowel duration depending on voicing in American, British, and New Zealand English

Hyesun Cho 한국음성학회 2016 말소리와 음성과학 Vol.8 No.3

It is well known that vowels are shorter before voiceless consonants than voiced ones in English, as in many other languages. Research has shown that the ratio of vowel durations in voiced and voiceless contexts in English is in the range of 0.6~0.8. However, little work has been done as to whether the ratio of vowel durations varies depending on English variety. In the production experiment in this paper, seven speakers from three varieties of English, New Zealand, British, and American English, read 30 pairs of (C)VC monosyllabic words which differ in coda voicing (e.g. beat-bead). Vowel height, phonemic vowel length, and consonant manner were varied as well. As expected, vowel-shortening effects were found in all varieties: vowels were shorter before voiceless than before voiced codas. Overall vowel duration was the longest in American English and the shortest in New Zealand (NZ) English. In particular, vowel duration before voiceless codas is the shortest in New Zealand English, indicating the most radical degree of shortening in this variety. As a result, the ratio of vowel durations in varying voicing contexts is the lowest in NZ English, while American and British English do not show a significant difference each other. In addition, consonant closure duration was examined. Whereas NZ speakers show the shortest vowel duration before a voiceless coda, their voiceless consonants have the longest closure duration, which suggest an inverse relationship between vowel duration and closure duration.