• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.325-328
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• 1999

The aim of this paper is to measure the duration of Japanese 'sokuon' [t/k] and 'haneron' [m/n] pronounced by Korean and Japanese. It is revealed in this study that gemination of the Japanese 'sokuon' in Korean pronunciation lasts 1.5 times longer than a single consonant, whereas it lasts 2 times longer in Japanese pronunciation. The difference between Korean and Japanese seems to show the difficulty of perceiving and learning a foreign rhythmic pattern non-existent in the leaner's language. The gemination of [s] phoneme lasts 2 times as long as a single consonant in both Korean and Japanese pronunciation. On average, the duration of Japanese 'sokuon' [t/k/s] is 1.7 times longer than a single consonant in Korean pronunciation, whereas 2 times longer in Japanese pronunciation. The pronunciation of Japanese 'haneruon' by either Korean or Japanese produces a similar result: 1) gemination lasts longer than a single consonant, 2) the duration of the single [m] is longer than that of the single [n]; 3) gemination of [n] is 3 times as long as a single [n], whereas gemination of [m] is 2 times as long as a single [m].

• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.1-7
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• 2017

It was shown in speech production studies that the preparation unit of spoken word production is language particular, such as onset phonemes for English and Dutch, syllables for Mandarin Chinese, and morae for Japanese. However, there have been inconsistent results on whether the onset phoneme is a planning unit of spoken word production in Korean. In this study, two sets of experiments investigated possible influences of task demands on the phonological preparation in native Korean adults, namely, implicit priming and word naming with the form preparation paradigm. Only the word naming task, but not the implicit priming task, showed a significant onset priming effect, even though there were significant syllable priming effects in both tasks. Following the attentional theory ($O^{\prime}S{\acute{e}}aghdha$ & Frazer, 2014), these results suggest that task demands might play a role in the absence/presence of onset priming effects in Korean. Native Korean speakers could maintain their attention to the shared onset phonemes in word naming, which is not very demanding, while they have difficulties in allocating their attention to such units in a more cognitive-demanding implicit priming, even though both tasks involve accessing phonological codes. These findings demonstrate that there are cross-linguistic differences in the first selectable unit in preparation of spoken word production, but within a single language, the preparation unit might not be immutable.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.13-23
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• 2012

The sound /w/ has been traditionally regarded as an independent segment in Korean regardless of the phonological contexts in which it occurs. There have been, however, some questions regarding whether it is an independent phoneme in /CwV/ context (cf. Kang 2006). The present pilot study examined how Korean /w/ is realized in $/S^*wV/$ context by performing some perception tests. Our assumption was that if Korean /w/ is a part of the preceding complex consonant like $/C^w/$, it should be more or less uniformly articulated and perceived as such. If /w/ is an independent segment, it will be realized with speaker variability. Experiments I and II examined the identification rates as "labialized" of the spliced original stimuli of $/S^*-V/$ and $/S^{w*}-^wV/$, and the cross-spliced stimuli $/S^{w*}-V/$ and $/S^*-^wV/$. The results showed that round qualities of /w/ are perceived at significantly different temporal point with speaker and context variability. We therefore conclude that /w/ in $/S^*wV/$ context is an independent segment, not a part of the preceding segment. Full-scale examination of the production test in the future should be performed to verify the conclusion we suggested in this paper.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.7-15
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• 2017

The purpose of this study was to investigate the different aspects of word-initial liquid sounds in Korean according to generations. Five women in their 50s and seven in their 20s participated in the experiment. We examined FL (formant of liquids) and voice sustained time by using Praat software. Three English native speakers were asked to judge the Korean speakers' recorded speech samples for marking [l] or [r] using evaluation sheet. The results of the two experiments revealed three important aspects. First, there was a statistically significant difference between the two groups in the FL of the words 'racket' and 'ruby.' Second, we found statistically significant differences in 'rhythm', 'ruby' and 'litter' from the measurement of the duration of the acoustic data. Third, there was no difference in pronunciation between the two groups according to the phonemes of the original language. The results of this study showed that it is difficult to say that the duration of word-initial liquids and the phoneme difference of the original language are indicators to distinguish the word-initial liquids between generations. Also, it was seen that the pronunciation of Korean word-initial liquid sounds varied across generations.

• Phonetics and Speech Sciences
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• v.7 no.2
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• pp.103-109
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• 2015

This paper describes the development of the Korean corpus of spontaneous speech, also called the Seoul corpus. The corpus contains the audio recording of the interview-style spontaneous speech from the 40 native speakers of Seoul Korean. The talkers are divided into four age groups; talkers in their teens, twenties, thirties and forties. Each age group has ten talkers, five males and five females. The method used to elicit and record the speech is described. The corpus containing around 220,000 phrasal words was phonemically labeled along with information on the boundaries for Korean phrasal words and utterances, which were additionally romanized. According to the test result of labeling consistency, the inter-labeler agreement on phoneme identification was 98.1% and the mean deviation on boundary placement was 9.04 msec. The corpus will be made available for free to the research community in March, 2015.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.782-791
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• 1991

In the fields of pattern recognition such as speech recognition, several new techniques using Artifical Neural network Models have been proposed and implemented. In particular, the Multilayer Perception Model has been shown to be effective in static speech pattern recognition. But speech has dynamic or temporal characteristics and the most important point in implementing speech recognition systems using Artificial Neural Network Models for continuous speech is the learning of dynamic characteristics and the distributed cues and contextual effects that result from temporal characteristics. But Recurrent Multilayer Perceptron Model is known to be able to learn sequence of pattern. In this paper, the results of applying the Recurrent Model which has possibilities of learning tedmporal characteristics of speech to phoneme recognition is presented. The test data consist of 144 Vowel+ Consonant + Vowel speech chains made up of 4 Korean monothongs and 9 Korean plosive consonants. The input parameters of Artificial Neural Network model used are the FFT coefficients, residual error and zero crossing rates. The Baseline model showed a recognition rate of 91% for volwels and 71% for plosive consonants of one male speaker. We obtained better recognition rates from various other experiments compared to the existing multilayer perceptron model, thus showed the recurrent model to be better suited to speech recognition. And the possibility of using Recurrent Models for speech recognition was experimented by changing the configuration of this baseline model.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06c
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• pp.323-327
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• 1994

There have been three contrastive claims over the classification of Korean. To answer the classification question, timing variables which would determine the durations of syllable, word and foot were investigated with various words either in isolation or in sentence contexts using Soundcoup/16 on Macintosh P.C., and a total of 284 utterances, obtained from six Korean speakers, were used. It was found 1) that the durational pattern for words tended to maintain in utterances, regardless of position , subjects and dialects 2) that the syllable duration was determined both by the types of phoneme and by the number of phonemes, the word duration both by the syllable complexity and by the number of syllables, and the foot duration by the word complexity, 3) that there was a constractive relationship between foot length in syllables and foot duration and 4) that the foot duration varied generally with word complexity if the same word did not occur both in the first foot and in the second foot. On the basis of these, it was concluded that Korean is a word timed language where, all else being equal, including tempo, emphasis, etc., the inherent durational pattern for words tends to maintain in utterances. The main difference between stress timing, syllable timing and word timing were also discussed.

• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.95-101
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• 2014

This paper investigated the effects of frequency band limitation on perceptual characteristics of Korean consonants. Monosyllabic speech (144 syllables of CV type, 56 syllables of VC type, 8 syllables of V type) produced by two announcers were low- and high-pass filtered with cutoff frequencies ranging from 300 to 5000 Hz. Six listeners with normal hearing performed perception test by types of filter and cutoff frequencies. We reported phoneme recognition rates and types of perception error of band-limited Korean consonants to examine how frequency distortion in the process of speech transmission affect listener's perception. The results showed that recognition rates varied with the following factors: position in a syllable, manner of articulation, place of articulation, and phonation types. Consonants in the final position were stronger to the frequency band limitation than those in the initial position. Fricatives and Affricates are stronger than stops. Fortis consonants were less stronger than their lenis or aspirated counterparts. Types of perception error also varied depending on such factors as consonant's place of articulation: In case of bilabial stops, they were perceived as alveolar stops with while in cases of alveolar and velar stops, there were changes in phonation types without any change in the place of articulation.

• KIISE Transactions on Computing Practices
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• v.21 no.11
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• pp.713-720
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• 2015

As computing and network technologies are further developed, communication equipment continues to become smaller, and as a result, mobility is now a predominant feature of current technology. Therefore, demand for speech recognition systems in mobile environments is rapidly increasing. This paper proposes a novel method to recognize the Korean vowel 'ㅐ' as a part of a phoneme-based Korean speech recognition system. The proposed method works by analyzing a sequence of patterns in the time domain instead of the frequency domain, and consequently, its use can markedly reduce computational costs. Three algorithms are presented to detect typical sequence patterns of 'ㅐ', and these are combined to produce the final decision. The results of the experiment show that the proposed method has an accuracy of 89.1% in recognizing the vowel 'ㅐ'.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.129-136
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• 2012

Korean alveolar fricatives are late-developing speech sounds. Most previous research on phonemes used individual words or pseudo words to produce sounds, but word-level phonological analysis does not always reflect a child's practical articulation ability. Also, there has been limited research on articulation development looking at speech production by grammatical morphemes despite its importance in Korean language. Therefore, this research examines the articulation development and phonological patterns of the /s/ phoneme in terms of morphological types produced in children's spontaneous conversational speech. The subjects were twenty-two typically developing 3- and 4-year-old Koreans. All children showed normal levels in three screening tests: hearing, vocabulary, and articulation. Spontaneous conversational samples were recorded at the children's homes. The results are as follows. The error rates decreased with increasing age in all morphological contexts. Also, error percentages within an age group were significantly lower in lexical morphemes than in grammatical morphemes. The stopping of fricative sounds was the main error pattern in all morphological contexts and reduced as age increased. This research shows that articulation performance can differ significantly by morphological contexts. The present study provides data that can be used to identify the difficult context for articulatory evaluation and therapy of alveolar fricative sounds.