Speech Rhythm Metrics for Automatic Scoring of English Speech by Korean EFL Learners

장태엽,Jang, Tae-Yeoub The Korean Society Of Phonetic Sciences And Speech 2008 말소리 Vol.66 No.-

Knowledge in linguistic rhythm of the target language plays a major role in foreign language proficiency. This study attempts to discover valid rhythm features that can be utilized in automatic assessment of non-native English pronunciation. Eight previously proposed and two novel rhythm metrics are investigated with 360 English read speech tokens obtained from 27 Korean learners and 9 native speakers. It is found that some of the speech-rate normalized interval measures and above-word level metrics are effective enough to be further applied for automatic scoring as they are significantly correlated with speakers' proficiency levels. It is also shown that metrics need to be dynamically selected depending upon the structure of target sentences. Results from a preliminary auto-scoring experiment through a Multi Regression analysis suggest that appropriate control of unexpected input utterances is also desirable for better performance.

존 웰즈 교수의 초청 강연 초록

Wells, John The Korean Society Of Phonetic Sciences And Speech 1989 말소리 Vol.15 No.-

다음은 창립 10주년을 맞은 대한음성학회의 초청으로 내한한 런던대학의 음성학. 언어학과 교수인 존 웰스 교수가 1987년 9월 22일에 한글학회 강당에서 열린 창립 기념식장에서 "현대 세계의 음성학"이라는 제목으로 행한 특별강연의 초록이다. 전반부는 생략하고 후반부만을 원문과 우리말로 옮겨 싣는다. It is an honour to be speaking on phonetics at the invitation of the Phonetic Society of Korea. Through the Korean Hangout script, invented in the fifteenth century at the instigation of the great King Sejong, and the work Hunminjeongeum which describes it, this country has an important place in the world history of phonetics. Phonetics is the description and analysis of pronunciation. Spoken language can be investigated at three points: in the speaker (articulatory phonetics), in the hearer (auditory phonetics), and in the physical speech signal (acoustic phonetics)... Beginners in English who are Korean mother tongue have to learn to make the sound 'f' as in "coffee", which is a voiceless labio-dental fricative, lip on upper teeth. They also have to learn to make [\theta]sound in "think", a voiceless dental fricative.

Robust Histogram Equalization Using Compensated Probability Distribution

Kim, Sung-Tak,Kim, Hoi-Rin The Korean Society Of Phonetic Sciences And Speech 2005 말소리 Vol.55 No.-

A mismatch between the training and the test conditions often causes a drastic decrease in the performance of the speech recognition systems. In this paper, non-linear transformation techniques based on histogram equalization in the acoustic feature space are studied for reducing the mismatched condition. The purpose of histogram equalization(HEQ) is to convert the probability distribution of test speech into the probability distribution of training speech. While conventional histogram equalization methods consider only the probability distribution of a test speech, for noise-corrupted test speech, its probability distribution is also distorted. The transformation function obtained by this distorted probability distribution maybe bring about miss-transformation of feature vectors, and this causes the performance of histogram equalization to decrease. Therefore, this paper proposes a new method of calculating noise-removed probability distribution by using assumption that the CDF of noisy speech feature vectors consists of component of speech feature vectors and component of noise feature vectors, and this compensated probability distribution is used in HEQ process. In the AURORA-2 framework, the proposed method reduced the error rate by over $44\%$ in clean training condition compared to the baseline system. For multi training condition, the proposed methods are also better than the baseline system.

Narrative and Grammatical Analyses of Story-retelling in Chinese Speakers of Korean as a Second Language

백은아,손은남,강수균,박선희,이현혜,최경희,Paik Euna,Sohn Eun-Nam,Kang Soo-Kyoon,Park Sun-Hee,Lee Hyun-hye,Choi Kyoung-Hee The Korean Society Of Phonetic Sciences And Speech 2005 말소리 Vol.56 No.-

Although the narrative development and the acquisition of the Korean grammatical morphemes by monolingual Korean-speaking children have been studied extensively, little is known about the narrative characteristics and the processes through which native speakers of other languages (L2 speakers) use the Korean grammatical morphemes. To understand the similarities and differences between L1 and L2 narrative skills and Korean grammatical morpheme use, 13 native Chinese-speaking college students who are learning Korean as a second language were studied. L2 participants used significantly fewer words, subordinate clauses, connective morphological endings, and pronouns per T-unit. Their speech also illustrated significantly more omission and confusion (substitution) errors in the use of auxiliary words and verb endings. Some of the syntactic and morphological factors need to be considered for the intervention of speakers with limited Korean proficiency.

Semantic-Oriented Error Correction for Voice-Activated Information Retrieval System

Yoon, Yong-Wook,Kim, Byeong-Chang,Lee, Gary-Geunbae The Korean Society Of Phonetic Sciences And Speech 2002 말소리 Vol.44 No.-

Voice input is often required in many new application environments, but the low rate of speech recognition makes it difficult to extend its application. Previous approaches were to raise the accuracy of the recognition by post-processing of the recognition results, which were all lexical-oriented. We suggest a new semantic-oriented approach in speech recognition error correction. Through experiments using a speech-driven in-vehicle telematics information application, we show the excellent performance of our approach and some advantages it has as a semantic-oriented approach over a pure lexical-oriented approach.

A Use of Songs for Teaching Pronunciations in Elementary School

Hong, Kyung-Suk The Korean Society Of Phonetic Sciences And Speech 2001 말소리 Vol.41 No.-

How to teach intelligible, communicative pronunciation is a continuous question in the English education. Without good input, we can not expect good output. However, in EFL situation, it is very difficult to input the good English pronunciation, therefore, we have to find out the efficient and effective material for teaching pronunciation. One of the materials is song, because songs contain the linguistic and cultural traits of the language. The purpose of this paper is to clarify the reason why songs are good for teaching pronunciation. Koreans, who are syllable timed language users, have difficulties in English pronunciation of stress, rhythm, consonants cluster, linking or blending in connected speech. The 134 songs from wee sing are analyzed for how these traits show in songs. The result shows that we can acquire the traits easily and naturally through songs. And a lesson plan is offered as an example for teaching songs.

Modelling Duration In Text-to-Speech Systems

정현성,Chung Hyunsong The Korean Society Of Phonetic Sciences And Speech 2004 말소리 Vol.49 No.-

The development of the durational component of prosody modelling was overviewed and discussed in text-to-speech conversion of spoken English and Korean, showing the strengths and weaknesses of each approach. The possibility of integrating linguistic feature effects into the duration modelling of TTS systems was also investigated. This paper claims that current approaches to language timing synthesis still require an understanding of how segmental duration is affected by context. Three modelling approaches were discussed: sequential rule systems, Classification and Regression Tree (CART) models and Sums-of-Products (SoP) models. The CART and SoP models show good performance results in predicting segment duration in English, while it is not the case in the SoP modelling of spoken Korean.

Effects of Experience on the Production of English Unstressed Vowels

이보림,Lee, Bo-Rim,Guion Susan G. The Korean Society Of Phonetic Sciences And Speech 2006 말소리 Vol.60 No.-

This study examined the effect of English-language experience on Korean- and Japanese-English late learners' production of English unstressed vowels in terms of four acoustic phonetic features: F0, duration, intensity and vowel reduction. The learners manifested some improvement with experience. The native-like attainment of a phonetic feature, however, was related to the phonological status of that feature in the speakers' native language. The results suggest that the extent to which the non-native speakers' production of English unstressed vowels improved with English-language experience varied as a function of their native language background.

Articulatory and Acoustic Correlates of Korean /1/

권보영,Kwon Bo-Young The Korean Society Of Phonetic Sciences And Speech 2005 말소리 Vol.56 No.-

This study investigated the articulatory and acoustic correlates of Korean /1/. In particular, direct comparison between Korean /1/ and English /1/ was made to evaluate the current assumption about Korean /1/ such that Korean /1/ is phonetically similar to English clear /1/. The present study revealed that Korea /1/ is different from English /1/ in several properties. First, F2 for Korean /1/ is around 600-700 Hz higher than F2 for English /1/. The overall higher F2 for Korean /1/ is attributed to the fact that Korean /1/ involves tongue body raising while it lacks a dorsal gesture. Second, F3 value for Korean /1/ becomes significantly lower when the preceeding vowel is a back vowel. This kind of variable F3 pattern was not observed in English /1/. The current study relates the F3 lowering to the retroflexion of Korean /1/ in the back vowel context.

Adaptive Band Selection for Robust Speech Detection In Noisy Environments

Ji Mikyong,Suh Youngjoo,Kim Hoirin The Korean Society Of Phonetic Sciences And Speech 2004 말소리 Vol.50 No.-

One of the important problems in speech recognition is to accurately detect the existence of speech in adverse environments. The speech detection problem becomes severer when recognition systems are used over the telephone network, especially in a wireless network and a noisy environment. In this paper, we propose a robust speech detection algorithm, which detects speech boundaries accurately by selecting useful bands adaptively to noisy environments. The bands where noises are mainly distributed, so called, noise-centric bands are introduced. In this paper, we compare two different speech detection algorithms with the proposed algorithm, and evaluate them on noisy environments. The experimental results show the excellence of the proposed speech detection algorithm.