• Phonetics and Speech Sciences
• /
• v.13 no.2
• /
• pp.9-17
• /
• 2021

Voice onset time (VOT) is known to be a primary acoustic cue that differentiates voiced from voiceless stops in the world's languages. While much attention has been given to the sound change of Korean stops, little attention has been given to that of English stops. This study examines VOT of stop consonants as produced by English speakers in comparison to Korean speakers to see whether there is any VOT change for English stops and how the effects of stop, place, gender, and individual on VOT differ cross-linguistically. A total of 24 native speakers (11 Americans and 13 Koreans) participated in this experiment. The results showed that, for Korean, the VOT merger of lax and aspirated stops was replicated, and, for English, voiced stops became initially devoiced and voiceless stops became heavily aspirated. English voiceless stops became longer in VOT than Korean counterparts. The results suggest that, similar to Korean stops, English stops may also undergo a sound change. Since it is the first study to be revealed, more convincing evidence is necessary.

• Phonetics and Speech Sciences
• /
• v.7 no.1
• /
• pp.89-95
• /
• 2015

We explored Dutch listeners' perception of Korean three-way contrast of fortis, lenis, and aspirated stops. The three Korean stops are all voiceless word-initially, whereas Dutch distinguishes between voiced and voiceless stops, so Korean voiceless stops were expected to be difficult for the Dutch listeners. Among the three Korean stops, fortis stops are phonetically most similar to Dutch voiceless stops, thus they were expected to be the easiest to distinguish for the Dutch listeners. Dutch and Korean listeners carried out a discrimination task using three crucial comparisons, i.e., fortis-lenis, fortis-aspirated, and lenis-aspirated stops. Results showed that discrimination between lenis and aspirated stops was the most difficult among the three comparisons for both Dutch and Korean listeners. As expected, Dutch listeners discriminated fortis from the other stops relatively accurately. It seems likely that Dutch listeners relied heavily on VOT but less on F0 when discriminating between the three Korean stops.

• Phonetics and Speech Sciences
• /
• v.10 no.4
• /
• pp.91-99
• /
• 2018

Korean stops are currently undergoing a tonogenetic sound change, as found in the Seoul dialect in which a merged VOT of aspirated and lax stops induces F0 to be the primary cue for distinguishing the two stops and the lax stops have lower F0 than the aspirated stops. In tonal languages, low tone is produced with a breathy voice. This study investigated whether there are changes in voice quality with respect to the tonogenetic sound change of Korean stops. Two age groups speaking the Seoul dialect participated in this study: five females and six males born in the 1940s and 1950s and nine females and eight males born in the 1980s and 1990s. This study replicated previous findings of VOT and F0 and further examined H1-H2, H1-A1, and H1-A2 to see how they correlate with the sound change. In the older and younger generations, H1-H2, H1-A1, and H1-A2 were significantly lower after the tense stops than after the aspirated and lax stops, but they were not significantly different after the aspirated and lax stops. However, the younger females exhibited some different results for H1-H2 and H1-A2 than the older generation. In the younger females, the H1-H2 mean was higher after the aspirated stops than it was after the lax stops at the vowel onset, and the H1-H2 difference increased at the vowel midpoint. Although there was an inter-speaker variation in the results of H1-H2 and H1-A1, analyses of individual speakers showed that the H1-H2 and H1-A1 were higher after the lax stops than after the aspirated stops in the younger female speakers. These results indicate that lax stops tend to be breathier than aspirated stops in the younger female speakers. They also indicate that changes in voice quality are on Korean stops with tonal sound change, but are still developing.

• Speech Sciences
• /
• v.13 no.4
• /
• pp.51-67
• /
• 2006

This study examined the acoustic properties of initial stops in Korean, produced by Korean native speakers and English Korean learners. The productions of Korean native speakers were compared with those of beginners and advanced learners of Korean. Fundamental frequency(F0) and Voice Onset Time(VOT) were measured in condition of one or two syllable words, containing word-initial lenis, fortis, and aspirated stops. English Korean Learners showed that they produced stops with relatively shorter VOT and lower F0, compared with those of Korean native speakers. In case of the manner of articulation, English Korean learners have production difficulties in order of lenis stops, aspirated stops, and fortis stops. In regard to the place of articulation, English Korean learners showed production troubles in order of labial stops, velar stops, and alveolar stops. In the experiment of perception, it is hard for English Korean learners to distinguish stops of lenis and aspirated. Therefore, the results of production experiment were almost consistent with those of the perception experiment. Finally, according to both groups of proficiency, the results demonstrated that the advanced learners produce or perceive Korean stops easier than the beginners.

• Phonetics and Speech Sciences
• /
• v.8 no.1
• /
• pp.25-36
• /
• 2016

Previous studies showed that the voice onset time (VOT) of aspirated and lenis stops has been merged, and post-stop fundamental frequency (F0) has emerged as a primary cue to distinguish the two stops in the younger generation and female speech. The purpose of this study is to demonstrate that VOT merger in aspirated and lenis stops occurs after an F0 difference between the two stops becomes stabilized. In other words, unless post-stop F0, which is a redundant feature, is fully developed, it is hard for VOT merger to happen. Females have got a stable F0 difference in stops earlier than males. Therefore, VOT merger could happen, and as a result, females could take the lead in changing from VOT to F0 in initial stops. This study also shows that speakers who acquired F0 as a primary cue use F0 to the full to distinguish lenis stops from two other stops (aspirated and fortis).

• Phonetics and Speech Sciences
• /
• v.1 no.3
• /
• pp.39-48
• /
• 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
• /
• v.12 no.4
• /
• pp.57-61
• /
• 2020

Previous research has indicated that the patterns of phonetic modulations induced by prominence are not consistent across languages but are conditioned by sound systems specific to a given language. Most studies examining the prominence effects in Korean have been restricted to segments in word-initial and phrase-initial positions. The present study, thus, set out to explore the prominence effects for Korean stop consonants in word-medial intervocalic positions. A total of 16 speakers of Seoul Korean (8 males, 8 females) produced word-medial intervocalic lenis and aspirated stops with and without prominence. The prominence was induced by contrast focus on the phonation-type contrast, that is, lenis vs. aspirated stops. Our results showed that F0 of vowels following both lenis and aspirated stops became higher when the target stops received focus than when they did not, whereas voice onset time (VOT) and voicing during stop closure for both lenis and aspirated stops did not differ between the focus and no-focus conditions. The findings add to our understanding of diverse patterns of prominence-induced strengthening on the acoustic realizations of segments.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.8 no.2
• /
• pp.217-224
• /
• 1997

The present study was performed to investigate the voice onset time(VOT) of Korean stop consonants as the expanded research of Pyo and Choi(1996) : the intensity, and the air flow rate of Korean stops as the preliminary study f3r the classical singing training. Nine Korean stops(/P, P', $P^{h}$/, /t, t', $t^{h}$/, /k, k', $k^{h}$/) and a vowel /a/ were used as speech materials. CV and VCV syllable patterns were used for VOT measurement, and CV pattern was used for intensity and air flow rate measurement. Five males and five females pronounced the speech tasks with comfortable pitch and intensity : VOT, intensity, and air flow rate were measured. As results, the prevocalic stop consonants showed bilabials, the shortest VOT and velars, the longest one, except the unaspirated stops which showed the shortest was velar /k'/, and the alveolar /t'/ was the longest. Considering the tensity, heavily aspirated stops showed the longest, and the unaspirated, the shortest. Also the intervocalic stops showed similar results with the prevocalic stops, except the slightly aspirated stops which showed alveolar sound was the longest, and the bilabials, which showed the shortest was the slightly aspirated /p/, unlike the prevocalic stops, the unaspirated /p'/ the shortest. All of prevocalic stops showed the highest air flow rate in heavily aspirated stops, the second, thee slightly aspirated ones, and the lowest was the unaspirated stops. And as a whole, bilabials were the highest, and velars, the lowest, except in the heavily aspirated stops, which was the alveolar sound, the lowest. In the dimension of intensity, the unaspirated and bilabials were the highest, and the heavily aspirated and velars were e lowest, except the slightly aspirated stops, which were the bilabials the lowest, and the alveolars the highest.

• Speech Sciences
• /
• v.12 no.3
• /
• pp.153-164
• /
• 2005

Two identical experiments are conducted at a six month interval in order to examine the VOT and its effect on the whole syllable duration or the rest portion of the syllable in Busan Korean. Just like the general characteristics of VOT, the aspirated stops consistently exhibit the longest VOT while tense stops have the shortest VOT. However, alveolar stops exhibit shorter VOT than labial stops, and it is contrary to the previous studies which claim that VOT values of labial stops are shorter than VOT values of alveolar stops. Moreover, there is a relationship between VOT and syllable/VC duration across stops. While VOT and syllable/VC duration have symmetric relationship for the aspirated velar and bilabial stops, other lax and tense stops exhibit the inverse relationship between the VOT and syllable/VC duration.

• Speech Sciences
• /
• v.3
• /
• pp.71-82
• /
• 1998

Five sets of nonsense acoustical stimuli {$[sp{\varepsilon},st{\varepsilon},sk{\varepsilon}],\;[p{\varepsilon},t{\varepsilon},k{\varepsilon}],\;[sb{\varepsilon},sd{\varepsilon},sg{\varepsilon}],\;[b{\varepsilon},d{\varepsilon},g{\varepsilon}],\;['{\varepsilon}b{\varepsilon},'{\varepsilon}d{\varepsilon},'{\varepsilon}g{\varepsilon}]$} were presented for identification of English stops to native speakers of English, Chinese, and Korean. The English speakers perceived stops after /s/ as /p, t, k/; in other contexts as /b, d, g/. In the languages where other distinctions exist, however, the evaluation was different. The results suggest that in English the cue for stops after /s/ was syllable structure constraint: After initial /s/ always /p, t, k/ follow; the cue for the initial stops was aspiration. On the basis of the results, it was concluded that in English we should classify the unaspirated voiceless stops in initial /s/-stop clusters into the phoneme where [$p^{h},t^{h},k^{h}$] are in, and that perception is not only language specific but also context specific.