• Korean Journal of Cognitive Science
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• v.23 no.4
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• pp.425-455
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• 2012

Multi-dimensional verbal short-term memory mechanisms are largely divided into the phonological channel and the lexical-semantic channel. The former is called phonological short-term memory and the latter is called semantic short-term memory. Phonological short-term memory is further segmented into the phonological input buffer and the phonological output buffer. In this study, the language performance of each of three patients with similar levels of conduction aphasia was analyzed in terms of multi-dimensional verbal short-term memory. To this end, three patients with conduction aphasia were instructed to perform four different aspects of language tasks that are spontaneous speaking, repetition, spontaneous writing, and dictation in both word and sentence level. Moreover, the patients' phonological memories and semantic short-term memories were evaluated using digit span tests and verbal learning tests. As a result, the three subjects exhibited various types of performances and error responses in the four aspects of language tests, and the short-term memory tests also did not produce identical results. The language performance of three patients with conduction aphasia can be explained according to whether the defects occurred in the semantic short-term memory, phonological input buffer and/or phonological output buffer. In this study, the relations between language and multi-dimensional verbal short-term memory were discussed based on the results of language tests and short-term memory tests in patients with conduction aphasia.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.73-81
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• 2013

Coda in the word-medial position plays an important role in acquisition of our speech. Accuracy of the coda in the word-medial position is important as a diagnostic indicator since it has a close relationship with degrees of disorder. Coda in the word-medial position only appears in condition of connecting two vowels and the sequence causes diverse phonological processes to happen. The coda in the word-medial position differs in production difficulty by the initial sound in the sequence. Accordingly, this study aims to examine the tendency of producing a coda in the word-medial position with consideration of an optional phonological process in spontaneous speech of three and four year old children. Data was collected from 24 children (four groups by age) without speech and language delay. The results of the study are as follows: 1) Sonorant coda in the word-medial position showed a high production frequency in manner of articulation, and alveolar in place of articulation. When the coda in the word-medial position is connected to an initial sound in the same place of articulation, it revealed a high frequency of production. 2) The coda in word-medial position followed by an initial alveolar stop revealed a high error rate. Error patterns showed regressive assimilation predominantly. 3) The order of difficulty that Children had producing codas in the word-medial position was $/k^{\neg}/$, $/p^{\neg}/$, /m/, /n/, /ŋ/ and /l/. Those results suggest that in targeting coda in the word-medial position for evaluation, we should consider optional phonological process as well as the following initial sound. Further studies would be necessary which codas in the word-medial position will be used for therapeutic purpose.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.139-149
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• 2015

This paper aims to analyze pronunciation variations of loanwords produced by Korean and improve the performance of pronunciation modeling of loanwords in Korean by using syllable-based segmentation and phonological knowledge. The loanword text corpus used for our experiment consists of 14.5k words extracted from the frequently used words in set-top box, music, and point-of-interest (POI) domains. At first, pronunciations of loanwords in Korean are obtained by manual transcriptions, which are used as target pronunciations. The target pronunciations are compared with the standard pronunciation using confusion matrices for analysis of pronunciation variation patterns of loanwords. Based on the confusion matrices, three salient pronunciation variations of loanwords are identified such as tensification of fricative [s] and derounding of rounded vowel [ɥi] and [$w{\varepsilon}$]. In addition, a syllable-based segmentation method considering phonological knowledge is proposed for loanword pronunciation modeling. Performance of the baseline and the proposed method is measured using phone error rate (PER)/word error rate (WER) and F-score at various context spans. Experimental results show that the proposed method outperforms the baseline. We also observe that performance degrades when training and test sets come from different domains, which implies that loanword pronunciations are influenced by data domains. It is noteworthy that pronunciation modeling for loanwords is enhanced by reflecting phonological knowledge. The loanword pronunciation modeling in Korean proposed in this paper can be used for automatic speech recognition of application interface such as navigation systems and set-top boxes and for computer-assisted pronunciation training for Korean learners of English.

• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.119-125
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• 2014

Many studies have reported an age-related decline in the ability to spell words correctly. The aim of this study was to investigate the deterioration on retrieving orthographic knowledge in 64 normal elderly Korean persons. The subjects were 64 in total: they were composed of 22 persons in their 50s, 20 persons in their 60s, and 22 persons in their 70s or older. We instructed them to write from a dictation of 60 words stimuli (20 regular words, 20 irregular words, 20 nonwords). Older adults made more errors than younger adults, and the age-related decline in performance was greater for irregular than regular and nonwords. With respect to the error pattern in the irregular words, the subjects showed more phonological plausible errors than phonological implausible errors. The number of self-correction was high in nonwords. Based on the results, we found that aging differentially affects the retrieval of orthographic knowledge on regular, irregular and nonwords.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.49-56
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• 2017

Much research attention has been directed to identify how native speakers perceive non-native speakers' oral proficiency. To investigate the generalizability of previous findings, this study examined segmental, phonological, accentual, and temporal correlates of native speakers' evaluation of L2 Korean proficiency produced by learners with various levels and nationalities. Our experiment results show that proficiency ratings by native speakers significantly correlate not only with rate of speech, but also with the segmental accuracies. The influence of segmental errors has the highest correlation with the proficiency of L2 Korean speech. We further verified this finding within substitution, deletion, insertion error rates. Although phonological accuracy was expected to be highly correlated with the proficiency score, it was the least influential measure. Another new finding in this study is that the role of pitch and accent has been underemphasized so far in the non-native Korean speech perception studies. This work will serve as the groundwork for the development of automatic assessment module in Korean CAPT system.

• Korean Journal of Cognitive Science
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• v.26 no.1
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• pp.1-26
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• 2015

The purpose of this study was to examine whether the phonological information or the orthographic information plays a major role in visual word recognition. To do so, we used a non-word lexical decision task(LDT) in Experiment 1 and masked priming tasks in Experiement 2 and 3. The results of Experiment 1 showed that reaction times and the error rates were affected by the orthographic characteristics of the non-word stimuli such that orthographically similar non-words condition showed prolonged reaction times and higher error rates than control condition. In Experiment 2 and Experiment 3, the participants performed masked priming lexical decision tasks in two SOA conditions(60ms, 150ms). The results of the both experiments showed that the orthographically identical first syllable priming facilitated lexical decision of the target words while both of the pseudo-homophone priming and the phonologically identical first syllable priming did not. The dual route hypothesis(Coltheart et al, 2001), assuming that orthographic information rather than phonological information is the major source for the visual word recognition processes, fits well with the results of the current study.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.330-338
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• 2002

Spontaneous speech is ungrammatical as well as serious phonological variations, which make recognition extremely difficult, compared with read speech. In this paper, for conversational speech recognition, we analyze the transcriptions of the real conversational speech, and then classify the characteristics of conversational speech in the speech recognition aspect. Reflecting these features, we obtain the baseline system for conversational speech recognition. The classification consists of long duration of silence, disfluencies and phonological variations; each of them is classified with similar features. To deal with these characteristics, first, we update silence model and append a filled pause model, a garbage model; second, we append multiple phonetic transcriptions to lexicon for most frequent phonological variations. In our experiments, our baseline morpheme error rate (WER) is 31.65%; we obtain MER reductions such as 2.08% for silence and garbage model, 0.73% for filled pause model, and 0.73% for phonological variations. Finally, we obtain 27.92% MER for conversational speech recognition, which will be used as a baseline for further study.

• Annual Conference on Human and Language Technology
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• 1995.10a
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• pp.211-214
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• 1995

At what level of orthographic representation is phonology linked in thelexicon? Is it at the whole word level, the syllable level, letter level, etc? This question can be addressed by comparing the two scripts used in Korean, logographic Hanmoon and alphabetic/syllabic Hangul, on a task where judgements must be made about the phonology of a visually presented word. Four experiments are reported using a "homophone decision task" and manipulating the sub-lexical relationship between orthography and phonology in Hanmoon and Hangul, and the lexical status of the stimuli. Hangul words showed a much higher error rate in judging whether there was another word identically pronounced than both Hangul nonwords and Hanmoon words. It is concluded that the relationship between orthography and phonology in the lexicon differs according tn the type of script owing to the availability of sub-lexical information: the process of making a homophone derision is based on a spread of activation exclusively among lexical entries, from orthography to phonology and vice versa (called "Orthography-Phonology-Orthography Rebound" or "OPO Rebound"). The results are explained within the mulitilevel interactive activation model with orthographic units linked to phonological units at each level.

• English Language & Literature Teaching
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• v.13 no.1
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• pp.111-131
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• 2007

This study explores teacher's corrective feedback types in an error treatment sequence in Korean EFL classroom setting. Corrective feedback moves are coded as explicit correction, recast, or initiations to self-repair. The frequency and distribution of each corrective feedback type are examined. But the special focus was given on feedback types eliciting learner's self-repair (clarification request, metalinguistic feedback, elicitation, and repetition of error) because initiations to self-repair are believed to facilitate language learning more than other strategies. The results of the study are as follows. First, there was an overwhelming tendency for teacher to use recasts whereas initiations to self-repair were not used as much as recast (52.4% vs. 29.5%). Second, the teacher tended to select feedback types in accordance with error types: namely, recasts after phonological, lexical, and translation errors and initiations to self-repair after grammatical errors though the differences were not significant. Finally, teacher's belief and students' expectation on corrective feedback were compared with actual corrective feedback representations respectively and some mismatches were found. Though both teacher and the students acknowledged the importance and necessity of self-repair, self-repair were not put into practice as such. Therefore, this study suggests more initiations to self-repair be used for effective language learning.

• English Language & Literature Teaching
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• v.15 no.4
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• pp.237-264
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• 2009

The present study explores patterns of teachers' corrective feedback and learners' uptake in Korean EFL undergraduate classroom setting. It also examines consistencies and discrepancies in the perception of corrective feedback by teachers and learners. Teachers' and learners' preferences and perception of corrective feedback are further analyzed to determine whether or not those differ from actual practices in English language learning classrooms. The results of the study are as follows. First of all, teachers' corrective feedback type varied according to the learners' error type and English proficiency level. There was a lack of consistency between the teachers' feedback practices and the learners' error types. Second, for the phonological errors, learners' data witnessed the most frequent uptake on recast. For the other error types, however, the learners' uptake rates were high for the explicit corrective feedback. Third, the teachers' explicit knowledge of corrective feedback was rather low and the preferences differed from teacher to teacher. The teachers' feedback perception and preferences did not consistently reflect their actual practices. Finally, patterns of the learners' expectations of corrective feedback varied according to learners' proficiency level. Teachers' and learners' expectations of corrective feedback were also compared and some mismatches were detected.