• Phonetics and Speech Sciences
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• v.4 no.1
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• pp.21-28
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• 2012

Many previous studies reported acoustic parameters of English vowels produced by a clear speaking style. In everyday usage, we actually produce speech sounds with various speaking styles. Different styles may yield different acoustic measurements. This study attempts to examine pitch and formant trajectories of eleven English vowels produced by nine American males in order to understand acoustic variations depending on clear and conversational speaking styles. The author used Praat to obtain trajectories systematically at seven equidistant time points over the vowel segment while checking measurement validity. Results showed that pitch trajectories indicated distinct patterns depending on four speaking styles. Generally, higher pitch values were observed in the higher vowels and the pitch was higher in the clear speaking styles than that in the conversational styles. The same trend was observed in the three formant trajectories of front vowels and the first formant trajectories of back vowels. The second and third trajectories of back vowels revealed an opposite or inconsistent trend, which might be attributable to the coarticulation of the following consonant or lip rounding gestures. The author made a tentative conclusion that people tend to produce vowels to enhance pitch and formant differences to transmit their information clearly. Further perceptual studies on synthesized vowels with varying pitch and formant values are desirable to address the conclusion.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.1-5
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• 2004

A new method for the estimation of pitch-frequency contour of voiced speech is presented. The method is based on the double application of Kaiser's energy operator［1］, which has the capabilities of extracting amplitude and frequency of a sinusoidal waveform. According to the modulation model, a vowel can be represented by a combination of damped sinusoids representing formants, modulated by pitch pulses. Therefore, the amplitude envelope of each of the components will give a pitch-like waveform and the pitch can be obtained by averaging the frequencies of this waveform. The first part is the same as Gopalan's approach［9］, but by substituting the LPC based spectral analysis with the second application of energy operator, the algorithm becomes very simple and can be processed on-line. Although the estimation is rather coarse, the suggested algorithm can be useful for getting a general sketch of pitch contour on-line.

• Phonetics and Speech Sciences
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• v.16 no.2
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• pp.99-109
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• 2024

Coarticulation is affected by the continuous movement of the articulator within a limited time and space through the neighboring segments and various overlaps. This study investigated the differences in coarticulation characteristics of children with reading disabilities and nondisabled children in CVC and VCV syllables consisted of stops, affricates, and vowels (a, i, u). The subjects were 13 children with reading disabilities and nondisabled children in the 2nd to 6th grades in elementary school. Two second formants were measured. One was measured at the point where the vowel began, and the other was measured at the mid point of the vowel stable section. Regression analysis was performed with F2 onset and F2 of the following vowel to obtain the locus equation (LE). 3-way ANOVA was conducted to the slope of the LE according to the groups (reading disabilities vs. nondisabled), places of articulation, and phonation types. In CVC syllable, dyslexic children showed a flatter slope than nondisabled children. With respect to the places of articulation, velar or bilabial sounds showed steeper LE slope than alveolar or palatal sounds. There were no main effects regarding group and phonation types variable for VCV syllable, and the significant differences in the places of articulation were also differed from the results for the CVC syllables. This study confirmed that dyslexic children showed a different pattern of coarticulation slope depending on the syllable structure. We also found that the higher pause rate of the dyslexic children had a stronger effect on the coarticulation in VCV structures.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.1-14
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• 2020

Previous studies have confirmed that /o/ and /u/ in Seoul Korean are undergoing a merger in the F1/F2 space, especially for female speakers. As a substitute parameter for formants, it is reported that female speakers use phonation (H1-H2) differences to distinguish /o/ from /u/. This study aimed to explore whether H1-H2 values are being used as perceptual cues for /o/-/u/. A perception test was conducted with 35 college students using /o/ and /u/ spoken by 41 females, which overlap considerably in the vowel space. An acoustic analysis of 182 stimuli was also conducted to see if there is any correspondence between production and perception. The identification rate was 89% on average, 86% for /o/, and 91% for /u/. The results confirmed that when /o/ and /u/ cannot be distinguished in the F1/F2 space because they are too close, H1-H2 differences contribute significantly to the separation of the two vowels. However, in perception, this was not the case. H1-H2 values were not significantly involved in the identification process, and the formants (especially F2) were still dominant cues. The study also showed that even though H1-H2 differences are apparent in females' production, males do not use H1-H2 in their production, and both females and males do not use H1-H2 in their perception. It is presumed that H1-H2 has not yet been developed as a perceptual cue for /o/ and /u/.

• Phonetics and Speech Sciences
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• v.13 no.4
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• pp.1-7
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• 2021

This study aims to enhance English pronunciation education for Korean students by examining the impact of standard Korean and Gyeongsang regional dialect on the articulation of English vowels. Data were obtained through the Korean-Spoken English Corpus (K-SEC). Seven Korean words and ten English mono-syllabic words were uttered by adult, male speakers of standard Korean and Gyeongsang regional dialect, in particular, speakers with little to no experience living abroad were selected. Formant frequencies of the recorded corpus data were measured using spectrograms, provided by the speech analysis program, Praat. The recorded data were analyzed using the articulatory graph for formants. The results show that in comparison with speakers using standard Korean, those using the Gyeongsang regional dialect articulated both Korean and English vowels in the back. Moreover, the contrast between standard Korean and Gyeongsang regional dialect in the pronunciation of Korean vowels (/으/, /어/) affected how the corresponding English vowels (/ə/, /ʊ/) were articulated. Regardless of the use of regional dialect, a general feature of vowel pronunciation among Korean people is that they show more narrow articulatory movements, compared with that of native English speakers. Korean people generally experience difficulties with discriminating tense and lax vowels, whereas native English speakers have clear distinctions in vowel articulation.

• MALSORI
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• no.56
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• pp.29-47
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• 2005

Investigating and comparing English vowels $/{\varepsilon}/\;and\;/{\ae}/$, and their-supposedly- corresponding vowels in Korean /ㅔ/ and /ㅐ/, this study addresses the following questions: Do Koreans pronounce/ㅔ/ and /ㅐ/ differently? Do they pronounce English $/{\varepsilon}/\;and\;/{\ae}/$ differently? And what is the relationship between the Korean vowels and the English vowels? Is the conventional correspondence (/ㅔ:${\varepsilon}/$, and /ㅐ/:${\ae)/$ appropriate? The results showed that 24 Korean male college students distinguish neither Korean /ㅔ/ and /ㅐ/ nor English $/{\varepsilon}/\;and\;/{\ae}/$, thus suggesting that their inability to distinguish the two vowels in their native tongue has an effect on their production of the English vowels. While not distinguishable within a language, Korean /ㅔ/ and /ㅐ/ still form a separate group from English $/{\varepsilon}/\;and\;/{\ae}/$. But Korean-Produced $/{\varepsilon}/\;and\;/{\ae}/$ are significantly different from American-produced $/{\varepsilon}/\;and\;/{\ae}/:$ Korean-produced $/{\varepsilon}/\;and\;/{\ae}/$ have much lower F1 and F2 than American-produced counterparts. Accordingly it is advised that, in learning English pronunciation, Korean students should be instructed to take the English vowel system as a separate system from Korean one, and thus, not to substitute Korean vowels for English vowels. And students should be provided with specific instructions on the articulatory differences between English vowels and Korean vowels. For example, Cey should be instructed to lower their jaws more for English $/{\varepsilon}/\;and\;/{\ae}/$ than for Korean /ㅔ/ and /ㅐ/.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.101-113
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• 2020

This study aimed to explore how effective explicit form-focused instruction (FFI) is in teaching the schwa vowel /ə/ to EFL students in a classroom setting. The participants were 25 female high school students, who were divided into the experimental group (n=13) and the control group (n=12). One female American also participated in the study for a speech sample as a reference. The treatment, which involves shadowing model pronunciation by the researcher and a free text-to-speech software and the researcher's feedback in a private session, was given to the control group over a month and a half. The speech samples, for which the participants read the 14 polysyllabic stimulus words followed by the sentences containing the words, were collected before and after the treatment. The paired-samples t test and non-parametric Wilcoxon signed-rank test were used for analysis. The results showed that the participants of the experimental group in the post-test reduced the duration of the schwa by around 40 percent compared to the pre-test. However, little effect was found in approximating the participants' distribution patterns of /ə/ measured by the F1/F2 formant frequencies to the reference point, which was 539 Hz (F1) by 1797 Hz (F2). The findings of this study suggest that explicit FFI with multiple repetitions and corrective feedback is partly effective in teaching pronunciation.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.246-246
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• 1996

Purpose: Some of the properties of the prosodic phrasing and some acoustic and phonological effects of contrastive focus on the tonal pattern of Seoul Korean is explored based on a brief experiment of analyzing the fundamental frequency(=FO) contour of the speech of the author. Data Base and Analysis Procedures: The examples were chosen to contain mostly nasal and liquid consonants, since it is difficult to track down the formants in stops and fricatives during their corresponding consonantal intervals and stops may yield an effect of unwanted increase in the FO value due to their burst into the following vowel. All examples were recorded three times and the spectrum of the most stable repetition was generated, from which the FO contour of each sentence was obtained, the peaks with a value higher than 250Hz being interpreted as a high tone (=H). The result is then discussed within the prosodic hierarchy framework of Selkirk (1986) and compared with the tonal pattern of the Northern Kyungsang dialect of Korean reported in Kenstowicz & Sohn (1996). Prosodic Phrasing: In N.K. Korean, H never appears both on the object and on the verb in a neutral sentence, which indicates the object and the verb form a single Phonological Phrase ($={\phi}$), given that there is only one pitch peak for each $={\phi}$. However, Seoul Korean shows that both the object and the verb have H of their own, indicating that they are not contained in one $={\phi}$. This violates the Optimality constraint of Wrap-XP (=Enclose a lexical head and its arguments in one $={\phi}$), while N.K. Korean obeys the constraint by grouping a VP in a single $={\phi}$. This asymmetry can be resolved through a constraint that favors the separate grouping of each lexical category and is ranked higher than Wrap-XP in Seoul Korean but vice versa in N.K. Korean; $Align-x^{lex}$ (=Align the left edge of a lexical category with that of a $={\phi}$). (1) nuna-ka manll-ll mEk-nIn-ta ('sister-NOM garlic-ACC eat-PRES-DECL') a. (LLH) (LLH) (HLL) ----Seoul Korean b. (LLH) (LLL LHL) ----N.K. Korean Focus and Phrasing: Two major effects of contrastive focus on phonological phrasing are found in Seoul Korean: (a) the peak of an Intonatioanl Phrase (=IP) falls on the focused element; and (b) focus has the effect of deleting all the following prosodic structures. A focused element always attracts the peak of IP, showing an increase of approximately 30Hz compared with the peak of a non-focused IP. When a subject is focused, no H appears either on the object or on the verb and a focused object is never followed by a verb with H. The post-focus deletion of prosodic boundaries is forced through the interaction of StressFocus (=If F is a focus and DF is its semantic domain, the highest prominence in DF will be within F) and Rightmost-IP (=The peak of an IP projects from the rightmost $={\phi}$). First Stress-F requires the peak of IP to fall on the focused element. Then to avoid violating Rightmost-IP, all the boundaries after the focused element should delete, minimizing the number of $={\phi}$'s intervening from the right edge of IP. (2) (omitted) Conclusion: In general, there seems to be no direct alignment constraints between the syntactically focused element and the edge of $={\phi}$ determined in phonology; all the alignment effects come from a single requirement that the peak of IP projects from the rightmost $={\phi}$ as proposed in Truckenbrodt (1995).