• Speech Sciences
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• v.1
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• pp.201-211
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• 1997

Acoustically a naturally-spoken vowel is composed of five formants. However, the acoustic quality of a vowel is known to be mostly determined by $F_1\;and\;F_2$. The main purpose of this study was to examine how synthesized vowels with $F_1\;and\;F_2$ are perceived by Korean native speakers. In addion, we are interested in finding whether the synthesized vowels are perceived differently by standard Korean speakers and Kyungnam regional dialect speakers. In the experiment 9 Seoul standard Korean speakers and 9 Kyungnam dialect speakers heard 536 vowels synthesized in vowel space with $F_1\;by\;F_2$ and categorized them into one of 10 Korean vowels. The resultant vowel map showed that each Korean vowel occupies an unique area in the two-dimensional vowel space of $F_1\;by\;F_2$, and confirmed that $F_1\;and\;F_2$ play important roles in the perception of vowels. The results also showed that the Seoul speakers and the Kyungnam speakers perceive the synthesized vowels differently. For example, /e/ versus /$\varepsilon$/ contrast, /y/, and /$\phi$/ are perceived differently by the Seoul speakers, whereas they were perceptually confused by the Kyungnam speakers. These results might be due to the different vowel systems of the standard Korean and the Kyungnam regional dialect. While the latter uses a six-vowel system which has no /e/ vs /$/ contrast, /v/ vs /i/ contrast, /y/, and /$\phi$/, the former recognizes these as different vowels. This result suggests that the vowel system of differing dialect restricts the perception of the Korean vowels. Unexpectedly /i/ does not occupy any area in the vowel apace. This result suggests that /i/ cannot be synthesized without $F_3$.

• The Journal of the Acoustical Society of Korea
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• v.22 no.5
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• pp.360-366
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• 2003

Although multilayer perceptrons (MLPs) present several advantages against other pattern recognition methods, MLP-based speaker verification systems suffer from slow enrollment speed caused by many background speakers to achieve a low verification error. To solve this problem, the quantitative discriminative cohort speakers (QnDCS) method, by introducing the cohort speakers method into the systems, reduced the number of background speakers required to enroll speakers. Although the QnDCS achieved the goal to some extent, the improvement rate for the enrolling speed was still unsatisfactory. To improve the enrolling speed, this paper proposes the qualitative DCS (QlDCS) by introducing a qualitative criterion to select less background speakers. An experiment for both methods is conducted to use the speaker verification system based on MLPs and continuants, and speech database. The results of the experiment show that the proposed QlDCS method enrolls speakers in two times shorter time than the QnDCS does over the online error backpropagation(EBP) method.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.51-58
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• 2012

The purpose of this study is to measure the impact of Korean speakers' English stop pronunciation on their general pronunciation proficiency. For these purposes, 20 Korean speakers read English sentences and their pronunciations were rated by native English speakers. The Korean speakers' VOT values of English stops in sentences were then measured and the relation between the VOT values and native speakers' pronunciation rating was compared. Here, the relation between (1) the proficiency score of each speaker and VOT values; and (2) the proficiency score of each sentence and VOT values were analyzed. The results show that there is a relation between the proficiency score of each sentence and VOT values of /t, b, d, g/; and there is a relation between VOT values of /t, b, d, g/ and proficiency scores of each speaker while these is a weak relation between VOT values of /p, k/ and proficiency scores of each speaker.

• English Language & Literature Teaching
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• v.13 no.3
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• pp.23-40
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• 2007

This paper discusses why Korean speakers have problems in pronouncing some medial sonorant clusters in English. We argue that the main reasons lie in the sonority sequence requirement difference between the two languages. English does not have any specific sonority sequence preference between the medial sonorant sequences while Korean has a strict requirement between the two sonorants over a syllable boundary. This sonority sequence requirement difference between the two languages acts as an interference for Korean speakers in learning English pronunciation. This barrier for Korean speakers in acquiring correct pronunciation is implemented in a constraint ranking difference in the Optimality Theory, which is not familiar for Korean speakers. Understanding the details of sonorant production mechanisms along with the different constraint ranking will facilitate the learning process of Korean speakers learning English.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.23-29
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• 2016

The present study tested if individual speakers showing great sound change in segments (i.e., vowels and fricatives) also had innovative changing patterns in suprasegmental properties (i.e., lexical pitch accents) in Kyungsang Korean. The acoustic analysis at a group level first confirmed the presence of group level differences in distinguishing /ɨ-ʌ/ and /s-s'/ both of which had different phonemic distinction from Seoul Korean. Younger speakers had more innovative segmental change than older speakers, and even within the younger generation, female speakers produced more innovative phonetic variants than male speakers. Regarding the individual observation within the younger group, the younger speakers with large acoustic distinction in vowels and fricatives also showed acoustically less distinct accent patterns, indicating the innovative sound change pattern consistent across segment and suprasegmental properties. The group and individual observations suggested that linguistic innovators introduced new phonetic variants with consistent degree of changing pattern between segment and suprasegmental properties.

• MALSORI
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• no.38
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• pp.113-124
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• 1999

It is well known that Japanese prosodic structure assumes mora below the syllable tier. Syllables with V or CV structure are counted as having one morn whereas those with coda consonants /-pp, -tt, -kk, -ss, -N/ or long vowels are counted as having two morns in Japanese. This study measured the acoustic duration of these special moras ('tokusyuhaku') produced by Tokyo dialect speakers to see if they are isochronic with V or CV. It also examined the production of Korean(Seoul/Kyungsang dialect) and Chinese native speakers loaming Japanese as a second language to examine how the learners' first language influence their second language. Finally, it examined how speakers of the Akita dialect, which is blown as a syllabeme dialect in Japanese, produced them. The results showed that intra-speaker variation as well as inter-speaker variation was observed in the production by Akita dialect speakers. Production of native speakers of Chinese and Kyungsang dialect of Korean -- which have vowel length contrast in their phonological systems -- showed a similar result to Tokyo dialect speakers, which implies the influence of the learners' first language on the acquisition of the second language.

• MALSORI
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• no.65
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• pp.13-36
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• 2008

This paper attempts to analyze the characteristics of Korean vowel production by 12 Korean native speakers and 36 adult learners. The analyses have been performed with investigations of F1and F2 values. Results showed that there's no significant difference between /ㅔ/ and /H/ and between /ㅗ/ and /ㅜ/ in Korean native speakers' pronunciations. The distinguishing tendencies found in the analyses of foreign learners' pronunciations are fronting and lowering of /ㅗ/ by English speakers, backing and heightening of /ㅓ/ by Japanese speakers and backing and lowering of /ㅏ/ by Chinese speakers. For the limitations of this paper, it has a meaning of a preliminary study and could be developed into further research to show the order of acquisition and L1 transference.

• MALSORI
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• no.44
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• pp.15-32
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• 2002

The purpose of this study is to investigate the production of English vowels by native speakers of Korean. In the production test, two English speakers and four native Korean speakers served as subjects. The four native Korean speakers were divided into two groups, experienced and inexperienced. Native English speakers generally showed significant differences both in vowel duration and in F1 & F2 values between members of vowel pairs which are of special interest of this study: /i/l vs. /I/, /$\varepsilon$/ vs. /${\ae}$/, and /u/ vs. /$\mho$/. The overall results showed that the experienced group produced more accurate results in vowel duration, F1, and F2 values.

• Speech Sciences
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• v.7 no.2
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• pp.177-189
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• 2000

This paper investigates how individual speakers' speech can be distinguished using acoustic parameters such as amplitude, pitch, and formant frequencies. Word samples from fifteen male speakers in their 20's in three different regions were recorded in two different modes (i.e., casual and clear speech) in quiet settings, and were analyzed with a Praat macro scrip. In order to determine individual speakers' acoustical values, the total duration of voicing segments was measured in five different timepoints. Results showed that a high correlation coefficient between $F_1\;and\;F_2$ in formant frequency was found among the speakers although there was little correlation coefficient between amplitude and pitch. Statistical grouping shows that individual speakers' voices were not reflected in regional dialects for both casual and clear speech. In addition, the difference of maximum and minimum in amplitude was about 10 dB which indicates a perceptually audible degree. These acoustic data can give some meaningful guidelines for implementing algorithms of speaker identification and speaker verification.

• Speech Sciences
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• v.7 no.1
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• pp.53-64
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• 2000

Theoretically, alaryngeal speakers have difficulty in accomplishing the production of voiceless consonants. However, the perceptual studies often reveal a clear production of voiceless consonants giving good articulation scores in skilled alaryngeal speakers. The purpose of the present study was to clarify the production of voiceless stops in mode of articulation to normal speakers and skilled alaryngeal speakers. The acoustic characteristics of alaryngeal speech compared to the normal speech were investigated with special reference to the voiceless stop consonants. The surface electromyography from neck is used to monitor pharyngeal activity during speech. The general result is. that esophageal, shunt and neoglottal speakers realize the distinctions between the three types of [p] in a manner parallel to normals, whereas those using an electric voice generator do not.