• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.3-10
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• 2014

This study investigated whether Korean vowels, /ɨ/ and /u/, are distinctively perceived after a labial consonant given the fact that native and Sino-Korean nouns showed only vowel /u/ after a labial consonant while this pattern was massively broken by the recent introduction of loanwords. For this purpose, a perception experiment was conducted with $V_1C_1V_2$ sequences in which different vowels /a, i, u/ and consonants /p, t, k/ occurred in $V_1$ and $C_1$ before the target $V_2$, /ɨ/ and /u/. The data was produced by six speakers each from two different age groups, Age20 and Age40/50 in the read speech style. The results showed that consonant /p/ attracted significantly more responses of /u/ from /VCɨ/ sequences and significantly less responses of /u/ from /VCu/ sequence than the other consonants did in both age groups. Furthermore, Age20 group showed significantly less percentage of /u/ responses than Age40 group when the preceding consonant was /p/ regardless of the target vowel. We suggest therefore that unlike the traditional belief of labial assimilation, there is neutralization after a labial consonant in which vowels /ɨ/ and /u/ are often realized as any sound between two vowels, /ɨ/ and /u/. That is, this vowel change is not categorial but it rather produces an ambiguous stimulus which attracts different responses from different listeners. Ambiguous stimulus was produced due to coarticulatory efforts in speech production and perceptual compensation. We also argue that there is generational difference such that Age40/50 group speakers showed stronger tendency to produce /u/ after a labial consonant regardless of whether the target vowel was /ɨ/ or /u/.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.25-32
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• 2017

Besides their effect on the f0 contour of the following vowel, Korean stops are undergoing a sound change in which a partial or complete consonantal merger on voice onset time (VOT) is taking place between aspirated and lax stops. Many previous studies on sound change have mainly focused on group-normative effects, that is, effects that are representative of the population as a whole. Few systematic quantitative studies of change in adult individuals have been carried out. The current study examines whether the sound change holds for individual speakers. It focuses on inter-speaker and intra-speaker variability on sound change in contemporary Korean. Speech data were collected for thirteen Seoul Korean speakers studying abroad in America. In order to minimize the possible effects of speech production, socio-phonetic factors such as age, gender, dialect, speech rate, and L2 exposure period were controlled when recruiting participants. The results showed that, for nine out of thirteen speakers, the consonantal merger is taking place between the aspirated and lax stop in terms of VOT. There were also intra-speaker variations on the merger in three aspects: First, is the consonantal (VOT) merger between the two stops is in progress or not? Second, are VOTs for aspirated stops getting shorter or not (i.e., the aspirated-shortening process)? Third, are VOTs for lax stops getting longer or not (i.e., the lax-lengthening process)? The results of remarkable inter-speaker and intra-speaker variability indicate a synchronous speech sound change of the stop system in contemporary Korean. Some speakers are early adopters or active propagators of sound change whereas others are not. Further study is necessary to see whether the inter-speaker differences exceed intra-speaker differences in sound change.

• Speech Sciences
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• v.11 no.3
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• pp.69-81
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• 2004

The purpose of this experimental study was to investigate characteristics of Korean vowels uttered by Japanese speakers. Eight Korean Vowels were uttered three times by ten male Korean and Japanese, female Korean and Japanese, respectively. Formant Frequencies were measured from sound spectrograms made by the Pitch Works. Results showed that female Japanese speakers uttered Korean vowels more similar to those uttered by Korean native speakers than did male Japanese speakers.. In particular, male Japanese speakers have articulatory problems pronouncing the back vowels(/ㅓ/, /ㅡ/, /ㅜ/). It appears that the width of male speakers' articulatory movements is comparatively narrower than those of female speakers.

• Speech Sciences
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• v.4 no.1
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• pp.91-112
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• 1998

This paper aimed at examining the influence of L1 (native language) phonology when speakers of L1 perceive L2 (foreign language) sounds. Korean and Japanese learners of English took a perception test of Australian English words 'work', 'walk' and 'wok'. Based on Korean and Japanese phonology, it was predicted that Korean subjects would face more difficulties than Japanese subjects. The results of the experiment substantiated the influence of L1 phonology in L2 learners' L2 sound perception.

• MALSORI
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• no.35_36
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• pp.121-129
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• 1998

In this paper, articulatory simulator 'Artsim' is used as a tool for the experiments to examine the articulatory characteristics of 6 different vowels. Each vowels are defined by some articulatory points from their vocal tract area functions and shapes of tongues. Each points are varied systematically to synthesize vowels and the synthesized sound is evaluated by human listners. Finally distributions of each vowels within vowel space is obtained. From the experimental results it is verified that our articulatory simulator can be used effectively to investigate the articulatory characteristics of speech.

• The Journal of the Acoustical Society of Korea
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• v.11 no.3
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• pp.14-24
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• 1992

This paper is a study on the consonant recognition using neural network. First, the part of consonant was separated from the sound of vowel and consonant by the use of acoustic parameter. The rate of length vs. zero crossing rate in the sound of consonant had been studied by dividing each consonant into several groups. Finally, for the purpose of consonant recognition, the composite neural network which consists of a control network and several sub-network is proposed. The control network identifies the group to which the input consonant belongs and the sub-network recognizes the consonant in each group.

• The Journal of the Acoustical Society of Korea
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• v.11 no.3
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• pp.5-13
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• 1992

Taking devantage of the property that Korean digit is a mono-syllable word, we proposed a spoken Korean-digit recognition scheme using the multi-layer perceptron. The spoken Korean-digit is divided into three segments (initial sound, medial vowel, and final consonant) based on the voice starting / ending points and a peak point in the middle of vowel sound. The feature vectors such as cepstrum, reflection coefficients, ${\Delta}$cepstrum and ${\Delta}$energy are extracted from each segment. It has been shown that cepstrum, as an input vector to the neural network, gives higher recognition rate than reflection coefficients. Regression coefficients of cepstrum did not affect as much as we expected on the recognition rate. That is because, it is believed, we extracted features from the selected stationary segments of the input speech signal. With 150 ceptral coefficients obtained from each spoken digit, we achieved correct recognition rate of 97.8%.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.55-59
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• 1984

This paper describes a method of Hangout recognition using 2 - D digital filtering. The 170 patterns classified by the positions of the initial sound (consonant), middle sound (vowel) and terminal sound (consonant) of the 1,659 characters were established and models formed by using 2 - D digital filtering for each patterns were obtained. Based on these models we proposed an algorithm that can recognize KOREAN combinational characters by separating patterns from them with superpostion principles. As a result of simulation, 100% of recognition rate is obtained in the case of the print letter.

• Proceedings of the KSPS conference
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• 2006.11a
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• pp.127-130
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• 2006

The purpose of this study is to examine the difference in acoustic features between Young Voices and Aged Voices, which are actually come from the same age group. The 12 female subjects in their thirties were participated and recorded their sustained vowel /a/, connected speech, and reading. Their voices were divided into Younger Voices and Aged Voices, which means voices sound like younger person and sound like in their age or more aged ones. Praat 4.4.22 was used to record and analyze their acoustic features like Fo, SFF, Jitter, Shimmer, HNR, Pitch-range. And the six female listeners guessed the subjects' age and judged whether they sound younger or as like their actual age. We used the Independent t-Test to find the significant difference between those two groups' acoustic features. The result shows a significant difference in Fo, SFF. The above and the previous studies tell us the group who sounds like younger or baby like voice has the similar acoustic features of actually young people.

• Speech Sciences
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• v.9 no.1
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• pp.193-206
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• 2002

The aim of this study is to find out how the labiovelar onglide /w/ in English kwV sequences that have minimal pairs with kV sequences is pronounced differently among Korean EFL learners based on acoustic evidence. This study tries to identify /w/ sound in English kwV sequences through spectrograms and to examine the duration ratios of each segment in kwV words to compare the patterns of an English native speaker with those of Korean speakers of English. In spectrographic analyses, the complete deletion of /w/ and partial pronunciation of /w/ dubbed [$k^{w}$] were identified as well as the targetappropriate production of /w/. The general production patterns with respect to the duration ratios in English [kw] sequence words showed that the subjects who produced /w/ had similar ratio patterns that the native speaker had in that the vowel duration ratio in kwV sequences was shorter than that in kV sequences. By contrast, the subjects who deleted [w] had a long ratio of the onset [$k^{h}$] while the speaker with a partial pronunciation of /w/ had a long ratio of the following vowel.