• Proceedings of the KSPS conference
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• 2002.11a
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• pp.47-50
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• 2002

This paper is to introduce 'Dr. Speaking', which was recently developed by Eonon Inc.. 'Dr. Speaking' is an English pronunciation tutoring system. This has three distinguishing features. First, it teaches how to organize a speaker's vocal organs to pronounce accurately. Second, after it compares a speaker's pronunciation with that of a native speaker's, it grades that speaker's pronunciation level according to phonetic standards. Third, it provides proper information necessary for correcting a speaker's incorrect pronunciation. It is not always easy for a tutoring system to execute the above three almost simutaneously. However, 'Dr. Speaking' proved itself that it is possible by adding speech technology (e.g. speech recognition) to phonetic knowledge.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.3-10
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• 2011

This study investigates the role of suprasegmental features with respect to the intelligibility of Korean-spoken English judged by Korean and English raters as being good or bad. It has been hypothesized that Korean raters would have different evaluations from English native raters and that the effect may vary depending on the types of suprasegmental factors. Four Korean and four English native raters, respectively, took part in the evaluation of 14 Korean subjects' English speaking. The subjects read a given paragraph. The results show that the evaluation for 'intelligibility' is different for the two groups and that the difference comes from their perception of L2 English suprasegmentals.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.31-38
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• 2013

This study investigated the influence of English vowel pronunciation training to English word-initial stop pronunciation. For that purpose, VOT values of English stops produced by twenty Korean English learners(five Youngnam dialect male speakers, five Youngnam dialect female speakers, five Kangwon dialect male speakers, and five Kangwon dialect female speakers) were measured using the Speech Analyzer and their post-training production was compared with their pre-training production. The result shows that post-training VOT values of voiced stops became closer to those of native English speakers in all four groups. Hence, it can be inferred that vowel pronunciation training is effective for correcting pronunciation of voiced vowels by analyzing the change of the quality of following vowels(especially low vowels) and the degree of giving stress.

• Phonetics and Speech Sciences
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• v.4 no.4
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• pp.37-43
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• 2012

This study investigates an independent evaluation of prosody and segmentals with reference to the difference in the foreign accent of Korean, Chinese, and Japanese learners of English. For this study, a set of stimuli were made of English sentences read by male and female Korean, Chinese, and Japanese learners of English by prosody swapping technique. Two groups of American and Korean subjects evaluated the difference in the prosody and segmentals of the stimuli by pairwise difference rating. The results showed that there was no significant difference in the evaluation scores of prosody and segmentals across accents for either subject group. The results also showed that both subject groups indicated a greater score with segmentals than with prosody. The results of the present study are significant in that they are opposite to the claim of some previous studies that prosodic factors could have a greater influence on the foreign accent and intelligibility than segmentals.

• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.1-7
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• 2017

The purpose of this study is to investigate the relations between phonetic differences among Korean learners' production of English front vowels, pronunciation intelligibility and speaking proficiency test score. To do so, thirty Korean university students were asked (1) to read English text book paragraphs and (2) describe a picture. Two English native raters and one Korean rater evaluated Korean subjects' English pronunciation intelligibility and speaking. In addition, subjects' English vowel productions were acoustically analyzed(F0, F1, F2, vowel duration, intensity). The results of the study show that the vowel quality and pitch of the unstressed vowels and lax vowel are related to the pronunciation intelligibility. In addition, the scores of pronunciation intelligibility and speaking are highly related.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.17-20
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• 2005

The purpose of this project is to develop a device that can automatically measure pronunciation of English speech produced by Korean learners of English. Pronunciation proficiency will be measured largely in two areas; suprasegmental and segmental areas. In suprasegmental area, intonation and word stress will be traced and compared with those of native speakers by way of statistical methods using tilt parameters. Durations of phones are also examined to measure speakers' naturalness of their pronunciations. In doing so, statistical duration modelling from a large speech database using CART will be considered. For segmental measurement of pronunciation, acoustic probability of a phone, which is a byproduct when doing the forced alignment, will be a basis of scoring pronunciation accuracy of a phone. The final score will be a feedback to the learners to improve their pronunciation.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.71-74
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• 2003

In this paper, we present some of experimental results developed in computer-based English Pronunciation Correction System for Korean speakers. The aim of the system is to detect incorrectly pronounced phonemes in spoken words and to give correction comment to users. Speech data were collected from 254 native speakers and 411 Koreans, then used for phoneme modeling and test. We built two types of acoustic phoneme models: native speaker model and Korean speaker model. We also built langugage models to reflect Koreans' commonly occurred mispronunications. The detection rate was over 90% in insertion/deletion/replacement of phonemes, but we got under 75% detection rate in diphthong split and accents.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.103-113
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• 2016

This paper aims to propose articulatory features as novel predictors for automatic pronunciation assessment of English produced by Korean learners. Based on the distinctive feature theory, where phonemes are represented as a set of articulatory/phonetic properties, we propose articulatory Goodness-Of-Pronunciation(aGOP) features in terms of the corresponding articulatory attributes, such as nasal, sonorant, anterior, etc. An English speech corpus spoken by Korean learners is used in the assessment modeling. In our system, learners' speech is forced aligned and recognized by using the acoustic and pronunciation models derived from the WSJ corpus (native North American speech) and the CMU pronouncing dictionary, respectively. In order to compute aGOP features, articulatory models are trained for the corresponding articulatory attributes. In addition to the proposed features, various features which are divided into four categories such as RATE, SEGMENT, SILENCE, and GOP are applied as a baseline. In order to enhance the assessment modeling performance and investigate the weights of the salient features, relevant features are extracted by using Best Subset Selection(BSS). The results show that the proposed model using aGOP features outperform the baseline. In addition, analysis of relevant features extracted by BSS reveals that the selected aGOP features represent the salient variations of Korean learners of English. The results are expected to be effective for automatic pronunciation error detection, as well.

• Speech Sciences
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• v.15 no.3
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• pp.53-63
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• 2008

This paper examined the acoustic differences in English speech production between English native speakers and Korean learners. Korean speakers seem to produce errors by over-applying the Korean phonological rules(nasalization and lateralization) to English speech under the conditions comparable to those of Korean which contain nasal+lateral or lateral+nasal sequences. Being based on this prediction, the experimental data is grouped into three sets, [n]+[l] sequence, [l]+[n]sequence, and [m]+[l] sequence. The result shows that, Korean speakers usually nasalize or lateralize the target words or phrases in every three categories while English natives don't. In set A([n]+[l] sequence), both nasalization and lateralization were found in [n]+[l] sequence, the same circumstances where both nasalization and lateralization can be placed as in Korean. In the case of set B([l]+[n] sequence), only lateralization is observed. It is because the nasalization never occurs in the sequence of l-n in Korean. There is no lateralization in set C([m]+[l] sequence), because only nasalization occurs in the sequence of m-l in Korean. This results reconfirmed that the nasalization and lateralization rules in Korean deeply influence on the English production data. Korean speakers need to be taught not to over-apply Korean phonological rule to English production for accurate pronunciation.

• Speech Sciences
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• v.15 no.4
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• pp.19-27
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• 2008

Several studies on the pronunciation of English vowels point out that Korean learners have difficulty distinguishing English tense and lax vowel pairs. The acoustic comparisons of those studies are mostly based on the formant measurement at one time point of a given vowel section. However, the English lax vowels usually show dynamic changes across their syllable peaks and subjects' English levels account for various conflicting results. The purposes of this paper are to compare the temporal duration and dynamic formant tracks of English tense and lax vowel pairs produced by five Korean and five American males. The subjects were graduate students of an American state university. Results showed that both the Korean and American males produced the vowels with comparable durations. The duration of the front tense-lax vowel pair was longer than that of the back vowel pair. From the formant track comparisons, the American males produced the tense and lax pairs much more distinctly than the Korean male speakers. The results suggest that the Korean males should pay attention to the F1 and F2 movements, i.e., the jaw and tongue movements, in order to match those of the American males. Further studies are recommended on the auditorily acceptable ranges of F2 variation for the lax vowels.