• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.79-87
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• 2016

The purpose of this study aimed to examine the perceptual pattern of the Korean coda consonants by Chinese learners of Korean. Given that Mandarin allows only two nasals (/n, ŋ/) in the coda position, it was predicted that Chinese learners of Korean had difficulty in discriminating Korean coda consonants. In the experiment, the subjects were 21 beginner-level Chinese learners of Korean. They participated in the discrimination task four times a year in which they were asked to choose the right Korean coda consonants after listening the word from Korean native speakers. The results demonstrated that 1) Chinese learners of Korean improved their perception of the Korean coda consonants. 2) But Chinese learners of Korean performed differently according to the type of Korean coda consonants. Korean consonants /n, p, k, m/ showed significant differences, but /l, ŋ, t/ did not.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.167-169
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• 2007

This study analyzes Korean students' pronunciation errors in stop-nasal sequences in English. For the study, 23 English words of stop-nasal sequences were pronounced by 4 natives and 21 Korean students. The results showed two kinds of pronunciation errors: the insertion of a vowel and the nasal assimilation between stops and nasals. A teaching material was designed based on the errors. After a 60-minute class with the material they were asked to pronounce the same words in another session. There was a substantial improvement in the error correction.

• Proceedings of the KSPS conference
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• 2006.11a
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• pp.92-95
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• 2006

The purpose of this study is to find the acoustic parameters on frequency domain to distinguish the Korean nasals, /m, n, ng/ from each other. Since it is not easy to characterize the antiformant on frequency domain, we suggest the new parameters that are calculated by LTAS(Long term average spectrum). Maximum energy value and its frequency and minimum energy and its frequency of zero are obtained from the spectrum respectively. In addition, slope1, slope2, total energy value, centroid, skewness, and kurtosis are suggested as new parameters as well. The parameters that are revealed as to be statistically signigicant difference are roughly peak1_a, zero_f, slope_1, slope_2, highENG, zero_ENG, and centroid.

• The Journal of the Acoustical Society of Korea
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• v.8 no.5
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• pp.86-94
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• 1989

In this paper the method using a sign pattern( +,- ) of Mel-cepstrum coefficients as a new speech representation is proposed. Relatively stable patterns can be obtained for speech signals which has strong stationarity like vowels and nasals, and the phonemic difference according to the individuality of speakers can be absorbed without affecting characteristics of the phoneme. In this paper we show that the reduction of recognition procedure of phonemes and training procedure of phoneme models can be achieved through the representation of Korean phonemes using such a sign pattern.

• Speech Sciences
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• v.10 no.3
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• pp.7-27
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• 2003

Esophageal Speech uses the esophageal air during phonation. Fluent esophageal speakers frequently intake air in oral communication, but unskilled esophageal speakers are difficult with swallowing lots of air. The purpose of this study was to investigate the difference of acoustic characteristics of vowel and consonants production according to the speech proficiency level in esophageal speech. 13 normal male speakers and 13 male esophageal speakers (5 unskilled esophageal speakers, 8 skilled esophageal speakers) with age ranging from 50 to 70 years old. The stimuli were sustained /a/ vowel and 36 meaningless two syllable words. Used vowel is /a/ and consonants were 18 : /k, n, t, m, p, s, c, $C^{h},\;k^{h},\;t^{h},\;p^{h}$, h, I, k', t', p', s', c'/. Fundermental frequency (Fx), Jitter, shimmer, HNR, MPT were measured with by electroglottography using Lx speech studio (Laryngograph Ltd, London, UK). 36 meaningless words produced by esophageal speakers were presented to 3 speech-language pathologists who phonetically transcribed their responses. Fx, Jitter, HNR parameters is significant different between skilled esophageal speakers and unskilled esophageal speakers (P<.05). Considering manner of articulation, ANOVA showed that differences in two esophageal speech groups on speech proficiency were significant; Glide had the highest number of confusion with the other phoneme class, affricates are the most intelligible in the unskilled esophageal speech group, whereas in the skilled esophageal speech group fricatives resulted highest number of confusions, nasals are the most intelligible. In the place of articulation, glottal /h/ is the highest confusion consonant in both groups. Bilabials are the most intelligible in the skilled esophageal speech, velars are the most intelligible in the unskilled esophageal speech. In the structure of syllable, 'CV+V' is more confusion in the skilled esophageal group, unskilled esophageal speech group has similar confusion in both structures. In unskilled esophageal speech, significantly different Fx, Jitter, HNR acoustic parameters of vowel and the highest confusions of Liquid, Nasals consonants could be attributed to unstable, improper contact of neoglottis as vibratory source and insufficiency in the phonatory air supply, and higher motoric demand of remaining articulation due to morphological characteristics of vocal tract after laryngectomy.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.3-11
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• 2015

This study compared English and Korean speakers with regard to the nasalization of the English stops /b, d, g, p, t, k/before a nasal within and across a word boundary. Nine English and thirty Korean speakers participated in the experiment. We used 37 speech items with different grammatical structures. Overall the English informants rarely nasalized the stops while the Korean informants generally greatly nasalized them though widely varying from no nasalization to almost complete nasalization. In general, voiced stops were more likely to be nasalized than voiceless stops. Also, the alveolar stops /d, t/tended to be nasalized the most, the bilabial stops /b, p/ the second most, and the velar stops /g, k/ the least. Besides, the closer the grammatical relationship between neighboring words, the more likely the stop nasalization occurred. In contrast, the Korean syllabification - the addition of the vowel /i/ to the final stops - worked against the stop nasalization. On the other hand, different stress (accent) or rhythm effects of the two languages are assumed to contribute to the significantly different nasalization between English and Korean speakers. The spectrum of stop nasalization obtained from this study can be used as an index to measure how close a certain Korean speaker's stop nasalization is to English speakers'.

• Speech Sciences
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• v.12 no.2
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• pp.139-149
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• 2005

The purpose of this study was to propose a preliminary norm for 'Korean-Test of Articulation for Children(K-TAC)'. The K-TAC was designed to test 19 Korean consonants in various phonetic contexts through 37 words. We collected the data of 220 normally developing children aged 2;6(years;months) to 6;5. We analyzed the mean percentage of consonants correct and the age of acquisition for K-TAC. The results were as follows: first, The mean percentage was over 60% at late 2 years of age, over 80% at th age of 3, and over 90% after the age of 4. There were significant differences among age groups. Second, based on the criterion of correct production by 75% of children, Korean children acquired stops and nasals except for SF velars, glottal fricative, SF liquid and affricates by late 2 or 3 years of age. After that they acquired SF velars at the age of 4 and SI liquid at the age of 5. However, they could not acquire alveolar fricatives by the age of late 6. Third, if the distorted sounds were scored as correct, they acquired SI liquid at 4 years of age and alveolar fricatives at 5 years of age.

• Speech Sciences
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• v.14 no.3
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• pp.93-109
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• 2007

It is reported that the orthognathic patients suffer from not only aesthetic problems but also resonance disorder and articulation disorder because of the abnormality of the oral cavity. This study was designed to investigate the resonance of nasality and the intelligibility of speech for acoustic characteristics of patients' speech before and after orthognatic surgery. 8 orthognathic patients participated in the study. The nasality of words containing Korean consonants, Korean consonants and frequency and intensity of the fricative /s/ were measured using Nasometer and CSL (Computerized Speech Lab). Results were as follows: First, the nasality of post orthognathic surgery patients decreased in spontaneous speech. There was a significant difference in the nasality for all words between pre and post orthognatic surgery patients. Second, the nasality of each Korean consonant phoneme of post orthognathic surgery patients decreased. There was also a significant difference of the nasality for each Korean consonant phoneme between pre and post orthognatic surgery patients. Third, the decreased nasality for Korean consonant phonemes showed in plosives, affricates, fricatives, liquids, and nasals after surgery. But the significant difference showed only in plosives and fricatives. Finally, frequency and intensity for the fricative /s/ of post orthognathic patients increased.

• Speech Sciences
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• v.12 no.3
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• pp.139-151
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• 2005

Previous studies have shown that Korean students have difficulty identifying some English consonants which are not in the Korean sound inventory. The aim of this study was to examine the accuracy rate of English consonants correctly identified by 130 college students in order to find out which English consonants were difficult for the students to perceive. The subject's task was to identify one of the minimal pairs played in a quiet laboratory classroom. 100 minimal pairs consisted of syllables with various onsets or codas: stops, fricatives, affricates, liquids and nasals. Results were as follows: First, the average score of the English major group was significantly higher than that of the non-English major group. Second, there was a similar distribution in the rank order of minimal pairs sorted by the accuracy rate between the two groups. Third, the accuracy rate systematically decreased as each score range decreased. Fourth, the students showed higher accuracy in the perception of liquids than that of the stop-fricative contrast. Fifth, the accuracy score in onset position was higher than in coda position. Finally, the students still had problem telling voiced consonants from voiceless ones, especially in coda position. It would be desirable to extend the present research to middle or high school students to fundamentally resolve those listening problems.

• Phonetics and Speech Sciences
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• v.12 no.4
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• pp.19-25
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• 2020

This study examined thirty-one Korean students' pronunciation of an English passage using a speech recognition application, Speechnotes, and two Canadian raters' evaluations of their speech according to the International English Language Testing System (IELTS) band criteria to assess the possibility of using the application as a teaching aid for pronunciation education. The results showed that the grand average percentage of correctly recognized words was 77.7%. From the moderate recognition rate, the pronunciation level of the participants was construed as intermediate and higher. The recognition rate varied depending on the composition of the content words and the function words in each given sentence. Frequency counts of unrecognized words by group level and word type revealed the typical pronunciation problems of the participants, including fricatives and nasals. The IELTS bands chosen by the two native raters for the rainbow passage had a moderately high correlation with each other. A moderate correlation was reported between the number of correctly recognized content words and the raters' bands, while an almost a negligible correlation was found between the function words and the raters' bands. From these results, the author concludes that the speech recognition application could constitute a partial aid for diagnosing each individual's or the group's pronunciation problems, but further studies are still needed to match human raters.