• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.3-10
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• 2013

The purpose of this study is to analyze the acoustic characteristics of Korean alveolar sibilant sounds of children with cerebral palsy by acoustic analysis. Thirteen children with spastic cerebral palsy aging from 6 to 10 years old, were selected by an articulation test, and compared with a control group of thirty children. The meaningless monosyllable CV, disyllable VCV(/asa/) and frame sentence including target syllables CV were measured. C was from the /s, s'/, and V was from the set /a, i, u, ${\varepsilon}$, o, ɯ, ʌ/. Multi-Speech was used for data recording and analysis. As a result, the frication duration of lenis-glottalized alveolar sibilant of children with cerebral palsy was significantly shorter than that of the control group in CV, VCV and frame sentence. The vowel duration in the following lenis-glottalized alveolar sibilant of children with cerebral palsy was significantly longer than that of the control group in CV, VCV and frame sentence. The children with cerebral palsy showed frequency and intensity of friction intervals which were significantly lower than in the control group in CV, VCV and frame sentence. In the comparison of the lenis-glottalized alveolar sibilant by the children with cerebral palsy group's phonation types, the frication duration showed a significant difference between the phonation types in CV, VCV and between the phonetic contexts. The glottalized-sibilant was longer than the lenis-sibilant in all the phonetic contexts. The subsequent vowel duration showed a significant difference between the phonation types in VCV and between the phonetic contexts(p<.05). The vowel duration in the following glottalized-sibilant was longer than the vowel duration in the following lenis-sibilant in all the phonetic contexts. In the frequency there was a significant difference between the phonation types in CV, and in the intensity there was a significant difference between the phonation type in CV and VCV. The children with spastic cerebral palsy had difficulty in articulating the alveolar sibilant due to poor control ability in laryngeal, respiration and articulatory movements which require fine motor coordination. This study quantitatively analyzes the acoustic parameters of the alveolar sibilant in various phonetic contexts. Therefore, the results are expected to help provide fundamental data for an intervention of articulation treatment for children with cerebral palsy.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.37-46
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• 2010

This study investigates acoustic characteristics of English and Korean voiceless sibilant fricatives as they appear before the three vowels, /i/, /$\alpha$/ and /u/. Three measurements - duration, center of gravity and major spectral peak - are employed to compare acoustic properties and vowel effect for each fricative sound. This study also investigates the question of whether Korean sibilant fricatives are acoustically similar to the English voiceless alveolar fricative /s/ or to the palato-alveolar /$\int$/. The results show that in the duration of frication noise, English /$\int$/ is the longest and Korean lax /s/ the shortest of the four sounds. It is also observed that English alveolar /s/ has the highest value, whereas Korean /s/ shows the lowest value in the frequency of center of gravity. In terms of major spectral peak, while English /s/ reveals the highest frequency, English /$\int$/ shows the lowest value. In addition, evidence indicates that there is a strong vowel effect in the fricative sounds of both languages, although the vowel effect patterns of the two languages are inconsistent. For instance, in the major spectral peak, both Korean lax /s/ and tense /$s^*$/ show significantly higher frequencies before the vowel /$\alpha$/ than before the other vowels, whereas both English /s/ and /$\int$/ exhibit significantly higher frequencies before the vowel /i/ than before the other vowels. These results indicate that Korean sibilant fricatives are acoustically distinct from both English /s/ and /$\int$/.

• Phonetics and Speech Sciences
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• v.13 no.1
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• pp.37-44
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• 2021

While recent acoustic studies have reported associations of fronted sibilants (fricatives /s s⁎/ and affricates /tɕ tɕ⁎/) with gender in Seoul Korean, there have not been any studies examining the relationship of the variants with adult speakers' ages. The current study analyzes sibilant productions from 39 adult speakers born between 1942 and 2008 (19 females) in terms of spectral peak frequencies (SPFs) in frication, an acoustic index of place of articulation (POA). The results indicate some phonetic contexts where higher sibilant SPFs, i.e., fronter POAs, are associated with younger adults and those fronted variants are realized in a gender-differentiated manner -- tense affricates and word-initial tense fricatives before /i/ in the females' productions, and word-medial tense fricatives before /a/ in the males' productions. The findings confirm that the distributions of the fronted sibilants are accounted for not only by the speakers' gender but also by their ages, indicating that the fronted variants are innovative forms of realizing sibilants in Seoul Korean. In addition, the current results convincingly show that the fronted sibilant variants are not mere reflections of individuals' physiological differences since they are not observed across all of the examined phonetic contexts.

• Phonetics and Speech Sciences
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• v.4 no.1
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• pp.67-74
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• 2012

The neutralization of /$s^h$/ and /$s^*$/ in Gyeongsang dialects is a culturally salient stereotype that has received relatively little attention in the phonetic literature. The current study is a more extensive acoustic comparison of the sibilant fricative productions of Seoul and Gyeongsang dialect speakers. The data presented here suggest that, at least for young Seoul and Daegu speakers, there are few inter-dialectal differences in sibilant fricative production. These conclusions are supported by the output of mixed effects logistic regression models that used aspiration duration, spectral mean of the frication noise, and H1-H2 of the following vowel to predict fricative type in each dialect. The clearest dialect difference was that Daegu speakers' /$s^h$/ and /$s^*$/ productions had overall shorter aspiration durations than those of Seoul speakers, suggesting the opposite of the traditional "/$s^*$/ produced as [$s^h$]" stereotype of Gyeongsang dialects. Further work is needed to investigate whether /$s^h/-/s^*$/ neutralization in Daegu is perceptual rather than acoustic in nature.

• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.31-38
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• 2017

This study aims to examine the acoustic characteristics of Korean sibilant, especially aspiration in Korean fricatives (plain: /s/, fortis: /s'/) and affricates (aspirated: /$ts^h$/, lenis: /ts/, and fortis: /ts'/). Duration values (closure duration, frication duration, aspiration duration), center of gravity (COG) (of the total duration, of the two portions, in 10 ms), H1-H2 values (at the vowel onset) were examined in order to investigate the phonetic feature of aspiration in frication noise. This study further discusses how to define criteria for identifying aspiration in sibilant sounds by adopting 3 visual criteria for assessing aspiration. This visually-designated aspiration onset points are further matched with the COG decline points in 10 ms windows. The result shows that all the non-fortis sounds (/s/, /$ts^h$/, /ts/) contain aspiration, causing similar values of COG and H1-H2.

• Phonetics and Speech Sciences
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• v.1 no.1
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• pp.47-52
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• 2009

The speech of Sino-Korean has been evolved from geopolitical cause since 1945. The aim of this study is to collect Yanji dialectal speech and to compare with South Korean dialectal speech. Twenty Yanbian university students participated as informants. Acoustic speech informations are analyzed using the Multi-Speech Windows Vista version. Dialectal speech characteristics of Yanji sino-Korean showed posterior vowel /${\alpha}$/, neutralization of mid-vowel /o/ between /o/ and /Ɔ/. Lenis stop sound showed the tendency of glottalization based on VOT value. Sibilant sound contains aspiration following constriction and lateral /l/ realized the approximant /r/.

• Speech Sciences
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• v.15 no.3
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• pp.31-38
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• 2008

The aim of this study was to find how English vowels affect the pronunciation of English sibilants /$d_3,\;{_3}$, z/ by Korean learners of English. Fifteen nonsense syllables composed by five vowels /a, e, i, o, u/ were pronounced six times by twelve Korean learners of English. Test scores were measured from the scoreboard made by a speech training software program, which was designed for English pronunciation practice and improvement. Results show that 1) the subjects had the lowest scores in /a_a/ position, and 2) subjects had lower scores in the /i_i/ position than in /e_e/, /o_o/ and /u_u/ positions when they pronounced $/d_3/,\;/{_3}/$, and /z/ in their respective inter-vocalic position. This study found that for the group studied Korean learners of English have more difficulty in pronouncing sibilants in /a_a/ and /i_i/ positions than in the other positions.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.59-65
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• 2010

In this paper, we investigate acoustic characteristics of Korean /s/ when it is followed by both a high front and a round segment regardless of their order to one another. We show that Korean /s/ in this environment has characteristics of a labio-palatalized segment, being affected by both a high front and a round segment if they occur within the domain of a syllable. In the experiment, we show that Korean /s/ before a high front and a round segment shows a spectral shape different from that in other environments. Specifically, it is different from /s/ before a high front segment only, showing peaks around 2.5 kHz. Furthermore, it shows a rapid decrease of amplitude in 4-5 kHz, and sometimes another plateau of high peaks in 5-6 kHz. We also examined center of gravity frequency and band energy difference. Based on the results of this experiment, we argue that Korean /s/ is affected by the following segments within the domain of coarticulation, a syllable and that the degree of coarticulation is different from language to language.

• 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.12 no.1
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• pp.1-9
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• 2020

The perceptual assimilation of a nonnative phonological contrast can change with linguistic experience, resulting in naïve listeners and novice second language (L2) learners potentially assimilating the members of a nonnative contrast to different native (L1) categories. While it has been shown that this sort of change can affect the discrimination of the nonnative contrast, it has not been tested whether such a change could have consequences for the production of the contrast. In this study, L1 speakers of Mandarin Chinese who were (1) naïve to Korean, (2) novice L2 learners, or (3) advanced L2 learners participated in a Korean non-word repetition task using word-initial sibilants. The initial CVs of their repetitions were then played to L1 Korean listeners who categorized the initial consonant. The naïve talkers were more likely to repeat an initial /s^ha/ as an affricate, whereas the L2 learners repeated it as a fricative, in line with how these listeners have been shown to assimilate Korean sibilants to Mandarin categories. This result suggests that errors in the production of new words presented auditorily to nonnative listeners may be driven by how they perceptually assimilate the nonnative sounds, emphasizing the need to better understand what drives changes in perceptual assimilation that accompany increased linguistic experience.