• Speech Sciences
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• v.13 no.2
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• pp.107-120
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• 2006

The main purpose of this study is to investigate whether Korean learners can use the vowel duration cue to distinguish voicing contrasts in word-final consonants in English. Given that the Korean group's performance on the auditory task was much better than their performance on the identification task or on the production task, we conclude that the AX discrimination task makes contact with a different layer of perception. In particular, the AX discrimination task can be done at the auditory or phonetic level, where differences in vowel length are still encoded in the representation. In contrast, the identification and production tasks are probing the mental representation of vowel length and voicing. It was also founded that Korean speakers stored neither vowel length nor voicing in memorized representations and did not internalize the lengthening of the preceding vowel as a rule to differentiate the voicing contrasts of final consonants, even though they were able to detect the acoustic differences in vowel duration provided that they were tested in an appropriate task.

• Cross-Cultural Studies
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• v.24
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• pp.112-119
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• 2011

This study presents experiments which examined the role of amplitude and fundamental frequency (f0) in the phonetic perception of short versus long stop length contrasts in Japanese (e.g., [t] vs. [tt]). Stop length contrasts are normally characterized by differences in the duration of stop closures. However, closure duration can be unreliable as a perceptual cue when one considers variability in the rate at which people speak. Acoustically, the amplitude and f0 of the vowel following stop consonants are known to covary with the length distinction of stops in Japanese. Given this fact, the current study examined amplitude and f0 as potential secondary cues to the distinction. The results indicate that even though both amplitude and f0 are robust correlates, Japanese listeners do not use these cues in categorizing short versus long stops.

• Proceedings of the KSPS conference
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• 2002.11a
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• pp.141-144
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• 2002

The relations between words intelligibility and sentences intelligibility were tested on adults with cerebral palsy(athetoid type). Intelligibility is used as an important evaluation value in the field of diagnosis and therapy of dysarthric patients. In order to develop one syllable phonetic contrast intelligibility test using specific phonetic contrasts, the correlation with sentences intelligibility was tested to find out the validity. Pearson's simple correlation coefficient was .83 that shows a high correlation. Also, comparing the range and standard deviation given by seven evaluators on each subject, it was shown that when evaluating patients of moderate intelligibility, words intelligibility was more reliable than sentences intelligibility.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.19-28
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• 2009

This paper reports experimental findings about the duration feature of the acoustic components of English stops in Korean speakers' voicing perception. In our experiment, 35 participants discriminated between recorded stimuli and digitally transformed stimuli with different duration features from the original stimuli. 72 sets of paired stimuli are generated to test the effects of the duration feature in various phonetic contexts. The result of our experiment is a complicated cross-tabulation with 540 cells defined by five categorical independent variables plus one response variable. To find a meaningful generalization out of this complex frequency table, we ran logit log-linear regression analyses. Surprisingly, we have found that there is no single effect of the duration feature in all phonetic contexts on Korean speakers' perception of the voicing contrasts of English stops. Instead, the logit log-linear analyses reveal that there are interaction effects among phonetic contexts (=C), the places of articulation of stops (=P), and the voicing contrast (=V), and among duration (=T), phonetic contexts, and the places of articulation. To put it in mathematical terms, the distribution of the data can be explained by a simple log-linear equation, logF=${\mu}+{\lambda}CPV+{\lambda}TCP$.

• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.694-702
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• 2003

The word intelligibility test for dysarthric speakers was designed to examine phonetic contrasts that are likely (1) to be sensitive to intelligibility impairment and (2) to contribute significantly to speech intelligibility. These phonetically contrasting word pairs were tested and proved to be reliable and to be valid, The results showed that in Korean dysarthric patients, the percentage of error in final position contrast was higher than in any other position. Unlike the results of previous studies, the initial-position contrasts were crucial in predicting the overall intelligibility among Korean patients.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.11-17
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• 2022

This study investigates closure durations of Korean stops in terms of laryngeal contrasts, places of articulation, and three positions within words. Twenty-two Korean speakers produced the nonsense words containing Korean stops found in word-initial and word-final positions and between vowels. The statistical results showed that the closure durations differed significantly by laryngeal contrast and place of articulation. In addition, the differences by position within words were marginally significant. The closure durations were in the order of lenis < aspirated < fortis stops by laryngeal contrast, velar < alveolar < bilabial stops by place of articulation, and word-final < word-initial < between vowels by positions within words. The laryngeal contrasts were neutralized in word-final position as per coda neutralization in Korean phonology. This study shows that closure durations should be considered a valuable phonetic cue to identify stops on par with voice onset time and f0.

• MALSORI
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• no.41
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• pp.73-81
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• 2001

This paper reports the results of an experimental phonetic study of intonation contrasts perception by speakers of British English, Japanese and Russian. Six series of re-synthesized two-syllable rise-fall contours with manipulated parameters of the rise in the first and the fall in the second syllable were employed in the experiment. Modifications of pitch height were executed in 2 st steps, and of duration in 30ms steps. The subjects, who were native speakers of British English, Japanese and Russian, identified the sentence type of presented re-synthesized stimuli. The results of the experiments demonstrate overall similarity of the perception strategies across the three groups of subjects, especially regarding the thresholds of declarative' sentence type judgement. Non-declarative judgements are more language-specific. The results can be employed for the teaching of English, Japanese and Russian as foreign languages as well as for speech synthesis and recognition.

• Proceedings of the KSPS conference
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• 2000.07a
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• pp.139-148
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• 2000

This paper reports the results of an experimental phonetic study of intonation contrasts perception by speakers of British English, Japanese and Russian. Six series of re-synthesized two-syllable rise-fall contours with manipulated parameters of the rise in the first and the fall in the second syllable were employed in the experiment. Modifications of pitch height were executed in 2 st steps, and of duration - in 30ms steps. The subjects, who were native speakers of British English, Japanese and Russian, identified the sentence type of presented re-synthesized stimuli. The results of the experiments demonstrate overall similarity of the perception strategies across the three groups of subjects, especially regarding the thresholds of 'declarative' sentence type judgement. Non-declarative judgements are more language-specific. The results can be employed for the teaching of English, Japanese and Russian as foreign languages as well as for speech synthesis and recognition.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.39-48
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• 2009

Previous studies on the effects of speaking rate on voice onset time (VOT) of stops in English, French, Icelandic, and Thai indicate that speaking rate asymmetrically affects VOT values. That is, pre-voiced and long-lag stops vary due to the rate factor more than short-lag stops do. One suggested explanation for this asymmetry is that it is due to the necessity of maintaining phonetic contrasts among the stop categories. Since pre-voiced and long-lag stops represent the ends of the VOT scale, they encompass broad swathes of that range and consequently allow for large variations. On the other hand, the VOT variations of short-lag stops may result in overlap with the VOTs of long-lag stops. This study aimed to explore the effects of speaking rate on the VOTs of Korean stops and see whether Korean fortis and lenis stops are limited in the degrees of variation as a function of rates due to the existence of stops with larger VOT values, lenis and aspirated stops respectively. Conversely, aspirated stops were expected to show more variation since there are no other categories with longer VOTs. Fortis, lenis, and aspirated stops in /CVn/ words (C = bilabial or velar stop, V = /i/ or /a/) were examined in isolation, and at normal and fast rates in a carrier sentence. Speaking rates were controlled by alternating words or sentences on a computer screen at intervals of two seconds for the isolation- and normal-rate conditions and one second for the fast-rate condition. This study found that while the VOTs of fortis stops did not change significantly, those of lenis and aspirated stops showed considerable changes as a function of speaking rates. Also, overlap between lenis and aspirated stops occurred considerably at all speaking rates. These phenomena were interpreted to relate to the fact that VOT contrasts between lenis and aspirated stops in Korean are currently being collapsed. Large variations of lenis stops as a function of rates seem to occur due to a weak motivation to limit the degree of variations for the purpose of maintaining phonetic contrasts. The significant overlap between lenis and aspirated stops at all rates was interpreted to occur because the VOT merger between the two categories became considerably fixed. Also the percentage of correctly-classified VOTs by optimal-boundary values between lenis and aspirated stops turned out to be lower than in previously-studied languages. This was interpreted to be further evidence that VOTs are losing their role in contrasting the two stop categories in Korean.

• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.17-27
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• 2009

Despite many studies on the production and perception of L2 phonemes, studies on how such phonemes are encoded lexically remain scarce. The aim of this study is to examine whether L2 learners have a perceptual problem with L2 suprasegmentals which are not present in their L1, or if they are able to perceive but not able to encode them in their lexicon. Specifically, Korean learners were tested to see if they could discriminate the vowel length differences in Japanese at the psychoacoustic level through a simple AX discrimination task. Then, a speeded lexical decision task with high phonetic variability was conducted to see whether they could use such contrasts lexically. The results showed that Korean learners of Japanese have no difficulties in discriminating Japanese vowel length contrast, but they are unable to encode such contrast in their phonological representation, even with long L2 exposure.