• 음성과학
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• 제10권2호
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• pp.223-236
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• 2003

The purpose of this experimental study is to investigate characteristics of English pitch accents uttered by Korean speakers. Six English sentences were uttered five times by fifteen male undergraduate and graduate students from three groups, Seoul, Yongnam and Honam dialect speakers. We compared the subjects' data with the data of a native speaker of English as model pronunciation of English pitch accents. Acoustic features(Fo, duration, amplitude) were measured from sound spectrograms made by the PC Works. Results showed that (1) acoustic features of English pitch accents are Fo and duration for the native speaker and Korean speakers altogether, (2) Seoul dialect speakers uttered English pitch accents more similarly to the English native speaker than the other dialect speakers and (3) Korean speakers generally have difficulties in pronouncing L* accents. It appears that Korean speakers have more problems in pronouncing L* accents than H* accents.

• 음성과학
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• 제11권1호
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• pp.117-130
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• 2004

This paper investigates the English intonation of Korean speakers of English as a second language and compares it to that of English native speakers. The speech data of ten Korean speakers and three native speaker controls were tape recorded in an oral reading task in which the subjects were asked to read aloud the given text which was used in the study of Wennerstrom (1994). Following Pierrehumbert and Hirschberg (1990) who distinguishes the discrete units of meaning in intonation, pitch accents, phrase accents and boundary tones were measured. It was found that Korean speakers' use of phrase accents and boundary tones were relatively good compared to their use of pitch accents. That is, Korean speakers conform to native speakers' use of phrase or boundary tones for the purpose of marking the relationship between intermediate or intonational phrases. In contrast, the main difference of Korean speakers' use of intonation from that of native speakers was the use of pitch accents. That is, Korean speakers tend to have difficulty in assigning an appropriate pitch accent to signal relationships between new or contrastive information and that which is assumed to be understood or contributes little to the meaning of the utterance.

• 음성과학
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• 제12권1호
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• pp.107-119
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• 2005

The current study considers that the distinctive acoustic properties and variations in the closed plateau are realized by four different pitch accents(/Hi*_ H*/ or /Hi*_$h*_f$ for an emphatic phrase and /hi*_ H*/ for a neutral phrase) in an intermediate phrase in the French intonational structure. Thus, an attempt is made to define the acoustic property of the CP in the ip according to the duration time and pitch range, while different combinations of the four pitch accents of the CP are used to explain the way a speaker will highlight. The duration time of the CP was measured at about 0.67 sec. for males and 0.75 sec. for females. The duration properties of the plateau in the CP were found to control the pitch range based on two different prominent pitch accents, which appeared in more than two APs. Therefore, the ip was identified as having a hierarchical level in the French intonational structure, along with the AP and IP. In addition, the CP in the ip was used as a specific location to explain the pragmatic meaning of the rhythm using the two acoustic factors and different combinations of the four pitch accents.

• 음성과학
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• 제10권2호
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• pp.303-318
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• 2003

This paper attempts to investigate the tonal implementations of English stress clash, arguing that a preceding stress shifts leftward when two lexical stresses conflict across word boundaries or that H* and L* pitch accents are alternatively manifested on the stressed syllables, establishing intonational peak and valley contours. We claim that the H*/L* alternation might be a tonal strategy to avoid stress clash, and that pitch could be solely manipulated to display a rhythmic effect with maintaining lexical stress. In the experiment, we examined two-word combinations whose boundaries involve stress clash, and divided them into two categories. One has the preceding words involving a heavy syllable ahead of stress to guarantee the place for a shifting stress and the other, a light syllable, in which case stress shift is completely prevented. We analyzed the distribution of pitch accents in the word combinations, focusing on the pitch configurations in the cases where stress should not be shifted. Results show that approximately 50% of the stimuli show stress shift in the heavy syllable combinations of the preceding words; the preceding stress is moved leftward within the word. The other 50% and the light syllable combinations show various pitch accents patterns; H* and L* alternation, deaccentuation of either stressed syllable, or L-insertion between two H* pitch accents, etc. We interpret this as a rhythmic effect of tone to avoid stress clash and suggest that a true stress clash would be confined into cases without H*/L* contours.

• The Journal of the Acoustical Society of Korea
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• 제23권4E호
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• pp.112-119
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• 2004

This paper presents a method for the automatic recognition of pitch accents with no prior knowledge about the phonetic content of the signal (no knowledge of word or phoneme boundaries or of phoneme labels). The recognition algorithm used in this paper is a time-delay recurrent neural network (TDRNN). A TDRNN is a neural network classier with two different representations of dynamic context: delayed input nodes allow the representation of an explicit trajectory F0(t), while recurrent nodes provide long-term context information that can be used to normalize the input F0 trajectory. Performance of the TDRNN is compared to the performance of a MLP (multi-layer perceptron) and an HMM (Hidden Markov Model) on the same task. The TDRNN shows the correct recognition of $91.9{\%}\;of\;pitch\;events\;and\;91.0{\%}$ of pitch non-events, for an average accuracy of $91.5{\%}$ over both pitch events and non-events. The MLP with contextual input exhibits $85.8{\%},\;85.5{\%},\;and\;85.6{\%}$ recognition accuracy respectively, while the HMM shows the correct recognition of $36.8{\%}\;of\;pitch\;events\;and\;87.3{\%}$ of pitch non-events, for an average accuracy of $62.2{\%}$ over both pitch events and non-events. These results suggest that the TDRNN architecture is useful for the automatic recognition of pitch accents.

• 음성과학
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• 제8권2호
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• pp.133-148
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• 2001

Focus and information structure are closely related with the distribution of pitch accents. A focused word conveys new information and bears a pitch accent. A content word can usually get a pitch accent, but it can be deaccented if it is mentioned earlier in the discourse. In this paper, we test how English native speakers and Korean learners of English realize pitch accents according to focus and information structure of a sentence. The production experiment shows that English native speakers give a pitch accent to narrow-focused items, deaccenting all the other items of the sentence. For VP broad focus, native speakers give a pitch accent either to both the verb and its complement or to the complement only. On the other hand, it is found that Koreans give pitch accents to most content words regardless of focus and information structure. Moreover, the perception experiment confirms that Koreans' intonation patterns, which are not appropriate in terms of focus and information structure, may jeopardize listeners' comprehension. This paper shows that Korean speakers have little knowledge about focus and information structure for intonational realization, and that such notions should be applied to teaching of English intonation.

• 음성과학
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• 제7권3호
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• pp.109-125
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• 2000

The purpose of this paper is to analyse the intonational meaning of various sentences based on the English Intonational Phonology, and to show the superiority of Intonational Phonology in explaining the intonational meanings in comparison with the other existing intonational theories. The American structuralists and British schools which attempt to describe the intonation in terms of 'levels' and 'configurations' respectively, analyze intonational meaning from a holistic perspective in which an utterance cannot be divided into smaller parts. On the other hand, Intonational Phonology considers English intonation as composed of a series of High and Low tones, and as a result, intonational meaning is interpreted compositionally as sets of H and L. In this paper, the phonological relations between intonation and its meaning from the compositions of pitch accents, phrase accents, and boundary tones which consist of an intonational tune are discussed.

• 음성과학
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• 제12권2호
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• pp.17-28
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• 2005

This paper argues that news speech entails a distinct intonational pattern from natural speech, effectively reflecting that it primarily focuses on providing new information. We conducted a phonetic experiment to compare the tonal contours between news speech and natural speech, examining the distributions of pitch accents and the overall pitch ranges. We utilized 70 American Press (AP) radio news utterances and 70 natural utterances extracted from TV dramas. Results show that news speech involves 3.38 H*'s (including L+H* and !H*) within an intonational phrase (IP) or intermediate phrase (ip) whereas natural speech, 1.8 in average. The number of IP/ip's per sentence is 3 in news speech, which is shown in the highest rate of 32.07% of the news speech, but it is merely 1, taking up the highest 41.42% in natural speech. Next, declination tends to be prevented in news speech, and the pitch range is much greater in news speech than in natural speech. Finally, a secondary stress syllable is comparatively frequently given a pitch accent in news speech, explicitly distinct from natural speech. These results can be interpreted as stating that news has the particular purpose of providing new information; every content word tends to be given a H* or its related pitch accent like L+H* or !H* because news speech assumes that every word conveys new information. This definitely brings about more IP/ip's per sentence due to a human physiological constraint; that is, more H*'s will cause more respiratory breaks. Also, greater pitch ranges and pitch accents imposed on secondary stress may be attributed to exaggerating new information.

• 음성과학
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• 제6권
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• pp.119-143
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• 1999

In this paper, the development of English Intonational Phonology is introduced. The existing representation systems of intonation are largely divided into the American structuralist school and the British school, which describe intonation by means of 'levels' and 'configurations' respectively. Both representation systems have some theory-internal problems, however. As for the American school, there is no way to represent pitches much lower than the reference line, while the system of intonation in the British school is limited in that intonation is described in a phonetic impressionistic way rather than from a phonological perspective. Intonational Phonology, a real phonological approach, which has grown out of the basic assumptions of autosegmental-metrical(AM) theory has been suggested by Pierrehumbert(1980). In her approach, an intonational tune is made up of one or more pitch accents, followed by an obligatory phrase accent and an obligatory boundary tone, and interestingly 22 combinations are possible. Intonational Phonology has been revised from Beckman & Pierrehumbert(1986) in developing ToBI(Tones & Break Indices), a proposed standard for labelling prosodic features of digital speech databases in English.

• 음성과학
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• 제7권2호
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• pp.97-112
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• 2000

This study examines how both English native speakers and Korean speakers realize the intonational tunes of English sentences when a sentence has two different meanings, through comparison of the utterances of the two groups of speakers. The results indicate that the English native speakers realize the difference in the meanings of given sentences in terms of differences in the boundary tones, as predicted in Pierrehumbert(1980) and Pierrehumbert & Hirschberg(l990), according to whom intonation is composed of a series of pitch accents, phrase tones, and boundary tones, and the meaning of a given sentence is delivered by the composition of the individual meanings of each component. The Korean speakers, however, fail to realize the difference in meaning with its boundary tones. Rather, they realize it by the number or positions of pitch accents and paralinguistic cues such as emotions and gestures. The Korean speakers, unlike the Americans, emphasize subject in sentences.