• MALSORI
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• no.33_34
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• pp.1-10
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• 1997

Korean stop consonants are well known for their tripple distinction. In word initial position lax, tense and aspirated consonants are all voiceless. They are differentiated by the degree of tension, aspiration and VOT(voice onset time). But in intervocalic position, lax consonants become voiced. In this study I compare the acoustic features of Korean intervocalic lax and tense stops. The closure duration of lax stops is shorter than that of tense consonants. The preceding vowel length is longer in tan than that in tense consonants. I modify the above acoustic characteristics by an experimental methods. For example, I shorten the closure duration of intervocalic tense stops by 5 steps. r also do auditory tests which will show us listener's reaction on the above examples. And do the same job with the preceding vowels. According to the auditory test, the closure duration does an important role in differentiating Korean intervocalic lax and tense stops. But the preceding vowel length has almost nothing to do with the distinction between lax and tense stops. So I conclude that acoustic features also have hierarchy. Some features have categorical characteristics and others don't.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.53-69
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• 1996

Much research has been done on the rues differentiating the three Korean stops in word initial position. This paper focuses on a more neglected area: the acoustic cues differentiating the medial tense and lax unaspirated stops. Eight adult Korean native speakers, four males and four females, pronounced sixteen minimal pairs containing the two series of medial stops with different preceding vowel qualities. The average duration of vowels before lax stops is 31 msec longer than before their tense counterparts (70 msec for lax vs 39 msec for tense). In addition, the average duration of the stop closure of tense stops is 135 msec longer than that of lax stops (69 msec for lax vs 204msec for tense). THESE DURATIONAL DIFFERENCES ARE 50 LARGE THAT THEY MAY BE PHONOLOGICALLY DETERMINED, NOT PHONETICALLY. Moreover, vowel duration varies with the speaker's sex. Female speakers have 5 msec shorter vowel duration before both stops. The quality of voicing, tense or lax, is also a cue to these two stop types, as it is in initial position, but the relative duration of the stops appears to be much more important cues. The duration of stops changes the stop perception while that of preceding vowel does not. The consequences of these results for the phonological description of Korean as well as the synthesis and automatic recognition of Korean will be discussed.

• Phonetics and Speech Sciences
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• v.11 no.2
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• pp.1-13
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• 2019

This study explored the relationship between accurate vowel production and proficiency levels in L2 English produced by Korean EFL adult learners. To this end, nine English vowels /i, ɪ, ɛ, æ, ʌ, ɔ, ɑ, ʊ, u/ were selected and adjacent vowels paired up (e.g., /i/-/ɪ/, /u/-/ʊ/, /ɛ/-/æ/, /ʌ/-/ɔ/, /ɔ/-/ɑ/). The spectral features of the pairs were measured instrumentally, namely F1 (indicating tongue height) and F2 (indicating tongue backness). Meanwhile, the durations as well as spectral features of the tense and lax counterparts in /i/-/ɪ/ and /u/-/ʊ/ were measured, as both temporal and spectral features are important in distinguishing them. The findings of this study confirm that higher-rated speakers were better able to distinguish the contrasts in the front vowel pairs /i/-/ɪ/ and /ɛ/-/æ/ than lower-rated learners, but in the central and back vowel pairs /u/-/ʊ/and /ʌ/-/ɔ/ (though not /ɔ/-/ɑ/), Korean EFL learners generally showed difficulty distinguishing adjacent vowels with spectral cues. On the other hand, the durations of the tense and lax vowels showed that the lower-rated speakers were less able to use the temporal feature to differentiate tense vowels from their lax counterparts, unlike previous studies that found that in general Korean learners depend excessively on the temporal cue to distinguish tense and lax vowels.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.326-336
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• 2022

This study aims to examine Korean learners' production of American English vowel focused on feature analysis. Specifically, the present study adopts feature analysis so that vowel production is analyzed in terms of vowel features as well as overall segmental accuracy. To this end, 22 Korean college students participated in a production test which contained 11 English vowels /i, ɪ, eɪ, ɛ, æ, ɑ, oʊ, ɔ, ʊ, u, ʌ/. The results revealed that the degree of difficulty varied depending on features; the Korean participants showed higher accuracy for front/back features than for tongue height features and tense/lax features. In particular, the participants had more difficulty producing back vowels and non-high vowels than front vowels and high vowels with respect to tongue height features and lip rounding features. Among the individual vowels, /eɪ/ showed the highest accuracy in feature analysis. On the other hand, /ɑ, ɔ, ʌ/ showed low accuracy with respect to height features and lip rounding features, and high vowels /i, ʊ, u/ showed low accuracy with respect to tense/lax features. As for the correlation between the vowel features, tongue height features and lip rounding features are significantly correlated. Also, tongue height features and tense/lax features showed a strong correlation. Finally, pedagogical implications for teaching English vowels were further discussed based on the findings of the current study.

• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.95-103
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• 2009

We investigated the perceptual structure of Korean consonants by analyzing the confusion among consonants in various vowel contexts. The 36 CV syllable types combined by 18 consonants and 2 vowels (/i/ and /u/) were presented with masking noises or in degraded intensity. The confusion data were analyzed by the INDSCAL (Individual Difference Scaling), ADCLUS (Additive Clustering) and the probability of the transmitted information. The results were compared with those of a previous study with /a/ vowel context (Bae and Kim, 2002). The overall results showed that the laryngeal features-aspiration, lax and tense-are the most salient features in the perception of Korean consonant regardless of vowel contexts, but the perceptual saliency of place features varies across vowel conditions. In high vowel (front and back vowel) contexts, sibilant consonants were perceptually salient compared to in low vowel contexts. In back vowel contexts, grave (labial and velar) consonants were perceptually salient. These findings imply that place features and vowel features strongly interact in speech perception as well as in speech production. All statistical measures from our confusion data ensured that the perceptual structure of Korean consonants correspond to the hierarchical structure suggested in the feature geometry (Clements, 1991). We discuss the link between speech perception and production as the basis of phonology.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.117-122
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• 2009

A variety of cross-linguistic studies has documented that the acoustic properties of speech addressed to young children include exaggeration of pitch contours and acoustically salient features of phonetic units. It has been suggested that phonetic modifications of child-directed speech facilitate young children's learning of speech sounds by providing detailed phonetic information about the target word. While there are several studies reporting vowel modifications in speech to infants (i.e., hyper-articulated vowels), there has been little research about consonant modifications in speech to young children (except for VOT). The present study examines acoustic properties of Korean stops in Korean mothers' speech to their children (seven children aged 27 to 38 months). Korean tense, lax, and aspirated stops are all voiceless in word-initial position, and are perceptually differentiated by several acoustic parameters including VOT, $f_0$ of the following vowel, and the amplitude difference of the first and second harmonics at the voice onset of the following vowel. This study compares values of these parameters in Korean child-directed speech to those in adult-directed speech from same speakers. Conclusions focus on the acoustic properties of Korean stops in child-directed speech and how they are modified to help Korean young children learn the three-way phonetic contrast.