• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.15-23
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• 2020

This study examines the duration of Korean lax and tense stops in the prosodic word-medial position, their interactions with nearby segments, and the phonological implications of these interactions. It first examines the lengthening of consonants at the function of the short lax stop. Experiment 1 shows that the sonorant C1 is significantly longer before a short lax stop C2 than before a long tense stop. Experiment 2 shows that the short lax stop C1 cancels the contrast between the lax and tense obstruent at C2, making them appear as long tense obstruents (Post-Stop Tensing Rule). We suggest that such lengthening phenomena occur in Korean to robustly preserve the contrastive length difference between C and CC. Second, this study examines the vowel shortening, known as Closed-Syllable Vowel Shortening, before a long tense stop or before the consonant sequence. Experiment 3 suggests that it be interpreted as temporal adjustment to make the interval from the onset of a vowel to the onset of the following vowel of near-equal length. Conclusively, we suggest that Korean speech be planned and controlled with two specific intervals. One is the duration of contrastive consonant intervals between vowels, and the other is the duration from the onset of a vowel to the onset of the following vowel.

• Phonetics and Speech Sciences
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• v.4 no.1
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• pp.13-20
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• 2012

A lax stop in Korean, one of the three laryngeal contrastive stops, has undergone a sound change in terms of its acoustic properties. Prior production studies described this recent lax stop as being differentiated from tense and aspirated stops primarily by fundamental frequencies (f0). And, the acoustic property of voice onset time (VOT) further separates tense stops from lax and aspirated stops. The current research explores how these two major acoustic parameters of f0 and VOT cue the three stop categories in Korean adult listeners' perception. Thirty-one native speakers of Korean participated in two experimental tasks: categorization judgment and within-category goodness ratings. Two sets of audio stimuli were prepared by synthesizing English and Korean male speakers' CV productions. The findings showed that while f0 cues listeners to lax stops as production patterns would predict, VOT were closely related to listeners' categorization and goodness ratings of lax stops. This suggests that accurate characterizations of the recent lax stop category need to be based on Korean speakers' perceptual behavior as well as production patterns.

• Speech Sciences
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• v.14 no.3
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• pp.7-19
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• 2007

The present study investigated some phonetic attributes which distinguish two Korean stop types $^-aspirated$ and $lax^-$ in a prosodic position which has previously received little attention, namely medial in an accentual phrase. The intonational pattern across syllables which are initial in an accentual phrase (Jun, 1993) is said to depend on the type of stop (aspirated or lax), while that of syllables which are medial in an accentual phrase are not. In Experiment 1, nine native Korean speakers read sentences with a controlled prosodic pattern in which aspirated or lax stops occurred in accentual phrase-medial position. Acoustic analysis revealed significant differences between aspirated and lax stops in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. The results indicate that a wider range of acoustic cues distinguish aspirated and lax Korean stops than previously demonstrated. Phonetic and phonological models of consonant-tone interactions for Korean will need to be revised to account for these results.

• Speech Sciences
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• v.14 no.4
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• pp.25-39
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• 2007

The present study investigated some perceptual phonetic attributes of two Korean stop types, aspirated and lax, in medial position of an accentual phrase. The intonational pattern across syllables (Jun, 1993) is argued to depend on the type of stop (aspirated vs. lax) only in the initial position of an accentual phrase. In Kang & Dilley (2007), we showed that significant differences between aspirated and lax stops in medial position of an accentual phrase exist in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. In the present perception experiment, we investigated whether these phonetic attributes contribute to the perception of these two types of stops: The closure durations and/or F0's of post-stop vowels on accentual-phrase medial words were altered and twenty native Korean speakers then judged these words as beginning with an aspirated or lax stop. Both closure duration and F0 significantly affected judgments of stop identity. These results indicate that a wider range of acoustic cues that distinguish aspirated and lax Korean stops in production also plays a role in perception. To account for these results we suggest some phonetic and phonological models of consonant-tone interactions for Korean.

• Speech Sciences
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• v.5 no.2
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• pp.17-26
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• 1999

It has been claimed that Korean mid-vocalic voiceless unaspirated lax stops are phonetically realized with voicing throughout the oral closure phase. Acoustic measurements were undertaken to examine the claim with four Korean native speakers using /$V_1CV_2$/ words where the vowel ($V_1\;=\;V_2$) was /i, a, u/ and the C was voiceless unaspirated lax stops /p, t, k/. Findings: (1) During mid-vocalic stops /k/ and /p/ the vowel /u/ was accompanied generally by a significant increase in voice cessation time as percentage of the oral closure interval (PCT) than the vowel /a/, regardless of subjects, whereas in mid-vocalic alveolar stop /t/ the effects of vowels on PCT were subject-dependent, (2) The effects of vowels on PCT were significantly greater in mid-vocalic /k/ than /p/, regardless of subjects, (3) The mean PCT, averaged across six tokens, ranged from 17% to100%, giving overall mean 61% in which the standard deviation was ${\pm}30$, and (4) Overall % of the total of mid-vocalic unaspirated lax stops were produced with a substantial period of devocing and voicing lag. Considering these results, it is difficult to agree with the existing claims that Korean voiceless unaspirated lax stops are phonetically realized with voicing throughout the oral closure phase. Other phonetic variables, including the durations of pre/post-stop vowels, voice onset time, voice cessation time, and the duration of oral closure, were measured.

• Speech Sciences
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• v.8 no.1
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• pp.93-111
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• 2001

This study investigates the contribution of vocalic information following the release of an initial stop to the identification of the three-way stop contrast (aspirated, lax, and tense) in Korean. Recent studies showed that there is a strong interaction between consonant types and tone. The findings raise questions concerning Korean listeners' use of tonal (or vocalic F0) variation in differentiation initial tense, lax, and aspirated stops. The above issues are addressed in the present study using a cross-splicing methodology. The overall results show that low vocalic F0 provided the most salient information for lax stops; tense and aspirated stop identification depended on a combination of VOT, F0, and H1-H2 characteristics. The perceptual dominance of F0 over VOT for lax stops is consistent with the size of the F0 difference in utterance-initial position, as well as their prominent role in Korean intonational phonology.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.41-47
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• 2017

The purpose of this study is to examine how speakers use VOT and f0 to distinguish tense, lax, and aspirated stops in isolated sentence reading and paragraph readings. To do so, a total of 20 males between the ages of 20-25 years old were asked to read (1) isolated sentences, (2) information-oriented text and (3) emotional expressive texts in which the stop pronunciation's VOT value and f0 were measured thereafter. The main results are as follows. In the isolate sentence reading, lax stops, and aspirated stops were distinguished by both VOT and f0, but for the Korean men that read reading texts, VOT is not a cue to distinguish between lax and aspirated stops. In general, the VOT differences between lax stops and aspirated stops were smaller for information-oriented texts and emotional expressive texts than that of the isolate sentence reading. In the paragraph reading that induces a natural utterance, the f0 dependence is greater for the distinction between lax and aspirated stops.

• 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.

• Speech Sciences
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• v.9 no.4
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• pp.113-130
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• 2002

Measurements were made of pressure rise time (PoRT), voice cessation time, flattened peak intraoral air pressure (Po), pressure static time (PoST), pressure-fall time and the duration of oral closure as four English speakers uttered isolated nonsense $V_{1}CV_{2}$ words containing /b/ and /p/ ($V_{1}=V_{2}$ and the V was /$\alpha$/), with stress on either $V_{1}orV_{2}$ alternately. The hypothesis tested was: The tense stop consonant. will be characterized either by a higher Po or a longer PoST, and/or by both against lax. Findings: (1) PoRT was significantly greater in /b/ than /p/, (2) the voiceless stop /p/ produced generally greater mean Po, averaged across five tokens, than its voiced counterpart /b/, but statistically insignificant, and (3) altogether, across stress, tokens and subjects, the difference in the calculated pressure static time (PoSTc), i.e., PoST + PoRT, between /p/ and /b/ was highly significant (p $\leq$ 0.003). Although further investigations remain to be taken, the results strongly supported the linguistic hypothesis of tense-lax distinction, with /b/ being lax and /p/ tense. Airflow resistance at the glottis and supraglottal air volume are assumed to be responsible for much of difference in PoRT between /p/ and /b/. The PoSTc reflecting, although indirectly, the respiratory efforts during the oral closure of a stop, was a convincing phonetic parameter of the consonantal tenseness based on respiratory efforts. The effects of stress on Po and PoSTc were inconsistent, and the shorter PoRT than consonantal constriction interval was always accompanied by Po and PoST.

• 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.