Three-way Stop Research Articles

Voice quality distinctions of the three-way stop contrast under prosodic strengthening in Korean*

Voice quality distinctions of the three-way stop contrast under prosodic strengthening in Korean*

Lack of early sensitivity and gradual emergence of native phoneme categories: A pattern from underrepresented language learners.

Perceptual narrowing of speech perception supposes that young infants can discriminate most speech sounds early in life. During the second half of the first year, infants' phonetic sensitivity is attuned to their native phonology. However, supporting evidence for this pattern comes primarily from learners from a limited number of regions and languages. Very little evidence has accumulated on infants learning languages spoken in Asia, which accounts for most of the world's population. The present study examined the developmental trajectory of Korean-learning infants' sensitivity to a native stop contrast during the first year of life. The Korean language utilizes unusual voiceless three-way stop categories, requiring target categories to be derived from tight phonetic space. Further, two of these categories-lenis and aspirated-have undergone a diachronic change in recent decades as the primary acoustic cue for distinction has shifted among modern speakers. Consequently, the input distributions of these categories are mixed across speakers and speech styles, requiring learners to build flexible representations of target categories along these variations. The results showed that among the three age groups-4-6 months, 7-9 months, and 10-12 months-we tested, only 10-12-month-olds showed weak sensitivity to the two categories, suggesting that robust discrimination is not in place by the end of the first year. The study adds scarcely represented data, lending additional support for the lack of early sensitivity and prolonged emergence of native phonology that are inconsistent with learners of predominant studies and calls for more diverse samples to verify the generality of the typical perceptual narrowing pattern. RESEARCH HIGHLIGHTS: We investigated Korean-learning infants' developmental trajectory of native phoneme categories and whether they show the typical perceptual narrowing pattern. Robust discrimination did not appear until 12 months, suggesting that Korean infants' native phonology is not stabilized by the end of the first year. The prolonged emergence of sensitivity could be due to restricted phonetic space and input variations but suggests the possibility of a different developmental trajectory. The current study contributes scarcely represented Korean-learning infants' phonetic discrimination data to the speech development field.

The influence of inter-dialect contact on the Korean three-way laryngeal distinction: An acoustic comparison among Seoul Korean speakers and Gyeongsang speakers with limited and extended residence in Seoul.

This exploratory study investigates the acoustic correlates of the Korean three-way laryngeal stop distinction in Gyeongsang long-term (LT) transplants who were born in the Gyeongsang region but moved to Seoul to pursue higher education. Acoustic data were collected from eight LT transplants, five short-term (ST) transplants, and 11 Seoul speakers to examine whether exposure to Seoul Korean (SK) affects Gyeongsang speakers' cue-weighting in distinguishing stops in production. LT transplants produced stimuli in both Gyeongsang and Seoul dialects. A cue-weighting model based on the acoustic data reveals that voice onset time (VOT) is less important to distinguish lenis from aspirated stops for Seoul speakers and for LT transplants' SK, as compared to ST transplants and LT transplants' Gyeongsang Korean (GK). In addition, fundamental frequency (F0) is more important for the lenis-aspirated distinction for Seoul speakers and LT transplants' SK, as compared to ST and LT transplants' GK, showing that LT transplants rely less on VOT and more on F0 to distinguish lenis from aspirated stops compared to ST transplants. LT transplants' SK reveals that they rely more on VOT and less on F0 compared to SK speakers. The cue-weighting model of the LT transplants provide empirical evidence that a series of sound changes in GK is due to inter-dialect contact.

The influence of inter-dialect contact on the Korean three-way laryngeal distinction: An acoustic comparison among Seoul, Gyeongsang, and bidialectal speakers

This study investigates the acoustic correlates of the Korean three-way laryngeal stop distinction in Gyeongsang-based Seoul bidialectal speakers who were born in the Gyeongsang region but moved to Seoul to pursue higher-level education. The main purpose is to examine whether exposure to Seoul Korean affects bidialectal speakers' cue-weighting strategy to distinguish stops in production. Acoustic data were collected from 8 bidialectal, 5 Gyeongsang speakers (GK), and 11 Seoul speakers (SK). Bidialectal speakers produced stimuli in both Gyeongsang and Seoul dialect. A cue-weighting model of measured data reveals that VOT is less important to distinguish lenis from aspirated stops for SK and for bidialectal speakers' SK compared to GK and bidialectal speakers' GK. In addition, F0 is more important for the lenis-aspirated distinction for bidialectal speakers' SK and for SK compared to GK and bidialectal speakers' GK, showing that bidialectal speakers rely less on VOT and more on F0 to distinguish lenis from aspirated stops compared to GK. Bidialectal speakers' SK reveals that they rely more on VOT and less on F0 compared to SK. These results provide empirical support to previous studies (e.g., Lee & Jongman, 2019) suggesting that a series of changes in GK are due to inter-dialect contact.

An acoustic description of Mixean Basque.

This paper presents an acoustic analysis of Mixean Low Navarrese, an endangered variety of Basque. The manuscript includes an overview of previous acoustic studies performed on different Basque varieties in order to synthesize the sparse acoustic descriptions of the language that are available. This synthesis serves as a basis for the acoustic analysis performed in the current study, in which the various acoustic analyses given in previous studies are replicated in a single, cohesive general acoustic description of Mixean Basque. The analyses include formant and duration measurements for the six-vowel system, voice onset time measurements for the three-way stop system, spectral center of gravity for the sibilants, and number of lingual contacts in the alveolar rhotic tap and trill. Important findings include: a centralized realization ([ʉ]) of the high-front rounded vowel usually described as /y/; a data-driven confirmation of the three-way laryngeal opposition in the stop system; evidence in support of an alveolo-palatal to apical sibilant merger; and the discovery of a possible incipient merger of rhotics. These results show how using experimental acoustic methods to study under-represented linguistic varieties can result in revelations of sound patterns otherwise undescribed in more commonly studied varieties of the same language.

A Phonetic Study of Korean Heritage Learners’ Production of Korean Word-initial Stops

The current study investigates heritage language (HL) learners’ production of the Korean three-way stop contrast. Korean consonants include a typologically rare distinction among three types of voiceless stops typically described as plain /p, t, k/, aspirated /ph, th, kh/, and tense /p*, t*, k*/. This study examines how this phonological contrast is implemented by HL learners enrolled in a beginning level Korean class at a university. Language-specific (i.e., English and Korean) gender effects in VOT are also explored in HL learners. The results show that voice onset time (VOT) mainly serves to differentiate tense stops from plain and aspirated stops, while f0 plays a significant role in differentiating plain from aspirated and tense stops in HL learners. This finding is consistent with accounts of sound change under way in current Korean stops. The inter- and intraspeaker variations or categorical confusion with Korean plain stops commonly shown in second language (L2) learners is not found in HL learners of this study. Hence, the results of the present study support the view that HL learners preserve the phonological and phonetic benefits in their HL. In terms of gender-based differences, VOT is found to be shorter for males in plain and aspirated stops, while it is longer for males in tense stops. Finally, this study also suggests that controlling the heterogeneity of subjects mitigates the methodological challenges of HL research.

Sources of variability in phonetic perception: The joint influence of listener and talker characteristics on perception of the Korean stop contrast

Where there is dialectal variability in production of a sound contrast, listeners from the two dialects may show parallel differences in perception. At the same time, perception is not static and can be influenced by other factors, including listeners’ experience with, and expectations about, different talkers. This work examines perception of the Korean three-way stop phonation contrast by listeners of two dialects of Korean. We examine to what extent listeners’ perception reflects production norms in their local community and, via a reverse matched-guise task, test whether their knowledge of cross-dialectal variability plays an active role in the way they categorize the contrast. While perception appears to reflect production norms on a broad level, we found age-related differences in perception, even for listener groups who showed no sign of a parallel difference in production. Furthermore, listeners showed different response patterns depending on the apparent dialect of the talker. Our results suggest that exposure to dialectal variability and expectations about the talker influence perception.

Context-dependent hyperarticulation of the Korean three-way laryngeal stop contrast in clear speech

We investigate whether and how speakers’ adaptation to feedback is reflected in hyperarticulation by comparing the productions of Korean aspirated, lenis, and fortis stops in plain versus clear speech. Ten Seoul Korean speakers were asked to read a stop-initial nonword and repeat the nonword after receiving misrecognition feedback that contained a contrasting stop. f0 and VOT were examined as main cues to the Korean stop distinction. Results showed that VOT was lengthened for aspirated and lenis stops in clear compared to plain speech. This difference in VOT was attributable to speakers’ modification in response to different types of feedback. VOT for aspirated stops was lengthened after both fortis and lenis feedback whereas VOT for lenis stops was lengthened only after fortis feedback. f0 did not show a difference between plain and clear speech. However, f0 enhancement for lenis and fortis stops depended on the type of feedback. f0 for lenis stops was lowered after aspirated feedback and raised after fortis feedback. Fortis stops’ f0 was lowered after aspirated and raised after lenis feedback. Overall, speakers can make local modifications in VOT and f0 in response to specific feedback, suggesting precise control in their effort to distinguish sounds and maintain intelligibility.

Pitch accent and the three-way laryngeal contrast in North Kyungsang Korean

Previous description of Korean’s three-way voiceless stop contrast notes differentiation in both voice onset time (VOT) and fundamental frequency (f0) on following vowels (Cho et al., 2002; Kang and Han, 2013; Kang, 2014). In a sound-change in-progress, however, VOT for lenis and aspirated stops has merged. The two are now differentiated primarily through f0 differences (Kang and Guion, 2008; Lee et al., 2013; Silva, 2006). North and South Kyungsang (NK and SK) are pitch accent dialects. SK has not undergone the change (Lee and Jongman, 2012): VOT is still a primary cue, potentially because f0 is already used for the pitch accent system (Lee et al., 2013). In NK, meanwhile, VOT for lenis and aspirated stops overlaps more for female than for male speakers, suggesting a possible change-in-progress (Holliday and Kong, 2011). As questions about the robustness of this change remain, we report data from 23 native NK speakers (6 older and 6 younger males; 5 older and 6 younger females). VOT and f0 findings suggest that the new pattern is incipient in NK: Older male talkers show the old pattern, younger female talkers the new pattern, and older female and younger male talkers fall between the two extremes.

Simple point of care continuous positive airway pressure delivery device (Jain-CPAP)

ObjectiveTo describe the effective pressure and FiO2 delivery to a realistic spontaneously breathing lung model using a novel, simple, inexpensive neonatal non-invasive bubble continuous positive airway pressure (CPAP) device.MethodsThis experimental...

The Perception and Production of Word-Initial Korean Stops by Native Speakers of Japanese.

Previous studies have shown that non-native speakers of Korean not only have difficulty producing the word-initial three-way stop contrast, but also exhibit a wide range of production patterns. Because these studies have only investigated native (L1) speakers of English and Mandarin and given the overall paucity of research on non-native Korean, it is not yet clear how dependent these findings are on the particular native language under investigation. The current paper reinforces our empirical grounding via extension to L1 speakers of Japanese. It is shown that although naïve Japanese listeners consistently perceive Korean fortis stops as voiced, and Korean lenis and aspirated stops as voiceless, novice second language learners do not produce any significant difference among the three stop categories, despite producing clear differences between their native Japanese stop categories. Unlike in previous studies of L1 speakers of English and Mandarin, there was very little inter-speaker variation, and all speakers produced all Korean stops with long lag voice onset time.

Predictions of Laryngeal Realism for breathy-voiced stops: Counter-evidence from Bangla

The Laryngeal Realism (LR) framework (Honeybone 2005, Beckman et al. 2013) argues that the breathy-voiced stops in the four-way stop systems are specified for multiple features: [voice] and [spread glottis] ([sg]). As a diagnostic of the specified features, Beckman et al. (2013) proposed that the acoustic cues for a specified feature be longer in slower speech. While predictions of the LR framework have been tested on two- and three-way stop systems using this technique, there has not been much on the four-way stop systems. This study presents evidence from Bangla and argues that the predictions of the LR framework apply variably for the breathy-voiced stops; [sg] is found to be the stronger candidate as the specified feature than [voice]. In slower speech, the cue for the breathy voicing (the lag-time) lengthened in the breathy-voiced stops. Contrarily, the acoustic cue for the [voice] feature (the prevoicing) was not affected by speech rate. Mixed-effects models confirmed that the effect of speech rate ...

Multivariate poisson lognormal modeling of crashes by type and severity on rural two lane highways

In an effort to improve traffic safety, there has been considerable interest in estimating crash prediction models and identifying factors contributing to crashes. To account for crash frequency variations among crash types and severities, crash prediction models have been estimated by type and severity. The univariate crash count models have been used by researchers to estimate crashes by crash type or severity, in which the crash counts by type or severity are assumed to be independent of one another and modelled separately. When considering crash types and severities simultaneously, this may neglect the potential correlations between crash counts due to the presence of shared unobserved factors across crash types or severities for a specific roadway intersection or segment, and might lead to biased parameter estimation and reduce model accuracy. The focus on this study is to estimate crashes by both crash type and crash severity using the Integrated Nested Laplace Approximation (INLA) Multivariate Poisson Lognormal (MVPLN) model, and identify the different effects of contributing factors on different crash type and severity counts on rural two-lane highways. The INLA MVPLN model can simultaneously model crash counts by crash type and crash severity by accounting for the potential correlations among them and significantly decreases the computational time compared with a fully Bayesian fitting of the MVPLN model using Markov Chain Monte Carlo (MCMC) method. This paper describes estimation of MVPLN models for three-way stop controlled (3ST) intersections, four-way stop controlled (4ST) intersections, four-way signalized (4SG) intersections, and roadway segments on rural two-lane highways. Annual Average Daily traffic (AADT) and variables describing roadway conditions (including presence of lighting, presence of left-turn/right-turn lane, lane width and shoulder width) were used as predictors. A Univariate Poisson Lognormal (UPLN) was estimated by crash type and severity for each highway facility, and their prediction results are compared with the MVPLN model based on the Average Predicted Mean Absolute Error (APMAE) statistic. A UPLN model for total crashes was also estimated to compare the coefficients of contributing factors with the models that estimate crashes by crash type and severity. The model coefficient estimates show that the signs of coefficients for presence of left-turn lane, presence of right-turn lane, land width and speed limit are different across crash type or severity counts, which suggest that estimating crashes by crash type or severity might be more helpful in identifying crash contributing factors. The standard errors of covariates in the MVPLN model are slightly lower than the UPLN model when the covariates are statistically significant, and the crash counts by crash type and severity are significantly correlated. The model prediction comparisons illustrate that the MVPLN model outperforms the UPLN model in prediction accuracy. Therefore, when predicting crash counts by crash type and crash severity for rural two-lane highways, the MVPLN model should be considered to avoid estimation error and to account for the potential correlations among crash type counts and crash severity counts.

Audit of Pediatric Transfusion Practices in a Tertiary Care Hospital: Expert's Opinion.

To the Editor: Bahadur et al. reported a retrospective audit of pediatric transfusion practices over a period of 3 mo at Lady HardingeMedical College, NewDelhi in the April, 2015 issue of this journal [1]. The authors observed an appropriate usage of blood components in 59.65 % requests, of 2,145 units issued. Appropriate requests were considered as those which conformed to the guidelines of transfusion practices. They have considered the utility of whole blood for neonatal exchange transfusion (ET) as ‘appropriate’ and observed that whole blood was appropriately (100 %) utilized for ET. In a correspondence, Aydin et al. from Turkey, have deliberated the subject of reconstituted packed red blood cells (PRBCs) vs. whole blood for neonatal ET [2]. They have commented that whole blood is generally an inappropriate choice for transfusions, particularly in pediatrics-neonatology. The argument favoring PRBCs reconstituted with plasma for ET is to minimize the anti-A and anti-B titers, in the appropriate setting. In ABO hemolytic disease, when ET is planned with O Rh-negative blood, O Rh-negative PRBCs suspended in AB plasma is ideal to minimize the anti-A and anti-B titers [3, 4]. For non-group O neonates, RBC units for ET (group O) are best resuspended in AB plasma or plasma of the baby’s blood group due to concerns over possible risks of hemolysis from the residual group O plasma [5]. Whole blood is rarely used for ET in the western world [5]. Whole blood is not readily available in most areas of the United States [6]. However, several centers prefer to reconstitute PRBCs for ET with plasma from the same donation where possible [5]; this practice, intended to reduce donor exposure, effectively renders the unit as a ‘whole blood’ from a single donor. As stated in British Transfusion Guidelines-2004, while there is no consensus, plasma-reduced red cells with a hematocrit of 0.50–0.60 should be suitable for ET [7]. Whole blood, with a hematocrit of 0.35–0.45 may result in a postexchange Hb of <12 g/dl in a severely anemic baby and thus increase subsequent donor exposure [7]. Surprisingly, there is a dearth of clinical evidence favoring the use of reconstituted PRBCs over whole blood for ET. In a study of 381 neonates by Yigit et al. fromTurkey, the reexchange rate was higher in the whole blood group, compared with the reconstituted PRBC for ABO hemolytic disease [3]. However, the study was retrospective. In addition, the two groups were significantly varied in gestational age, birth weight, as well as pre-ET bilirubin [3]. In contrast to the developed countries, whole blood is still available in majority of blood banks in India. Whole blood continues to be used for ET at several centers in India, plausibly for reasons of easy availability of whole blood and an unquestioned continuation of ‘conventional’ practice. With increasing availability of blood components and trained personnel in transfusion medicine and neonatology, this practice is likely to change with time. The note of caution is that the reconstitution of PRBCs should be conducted in the blood bank and ideally performed with a closed system [4]. This may not be available round the clock at all centers. A reconstitution performed at bedside with a three-way stop cock may result in a greater risk for error in appropriate dilution. The use of reconstituted PRBCs has gained favor over whole blood for ET for the above stated reasons. The clinical * Deepak Bansal deepakbansaldr@gmail.com

Individual differences in phonetic cue use in production and perception of a non-native sound contrast

The current work examines native Korean speakers' perception and production of stop contrasts in their native language (L1, Korean) and second language (L2, English), focusing on three acoustic dimensions that are all used, albeit to different extents, in both languages: voice onset time (VOT), f0 at vowel onset, and closure duration. Participants used all three cues to distinguish the L1 Korean three-way stop distinction in both production and perception. Speakers' productions of the L2 English contrasts were reliably distinguished using both VOT and f0 (even though f0 is only a very weak cue to the English contrast), and, to a lesser extent, closure duration. In contrast to the relative homogeneity of the L2 productions, group patterns on a forced-choice perception task were less clear-cut, due to considerable individual differences in perceptual categorization strategies, with listeners using either primarily VOT duration, primarily f0, or both dimensions equally to distinguish the L2 English contrast. Differences in perception, which were stable across experimental sessions, were not predicted by individual variation in production patterns. This work suggests that reliance on multiple cues in representation of a phonetic contrast can form the basis for distinct individual cue-weighting strategies in phonetic categorization.

Diachronic change in perception of Korean sibilants

The laryngeal contrast in the Seoul dialect of Korean is in a state of flux: the increasing importance of f0 (relative to VOT) in both perception and production of the three-way stop contrast in younger (vs. older) Seoul speakers has been well-documented. The current work turns to perception of the Korean sibilant series, comprised of a three-way affricate contrast, (fortis vs. lenis vs. aspirated, parallel to the stop contrast) and a phonologically ambiguous two-way fricative contrast (fortis vs. “nonfortis”). We map younger (mean 33 years old) and older (mean 66) Seoul listeners’ perceptual spaces for the sibilant class using a five-way forced-choice task, with stimuli manipulated to vary independently across multiple acoustic dimensions (consonantal spectral information, vocalic spectral information, frication duration, aspiration duration, and f0). Hierarchical classification tree analyses reveal systematic age-related differences in cue-weighting. While both age groups make use of a combination of sp...

A longitudinal study of the second language acquisition of a three-way stop contrast

The goal of this paper was to document how native (L1) speakers of a language with a two-way stop contrast acquire a three-way stop contrast in a second language (L2). Mandarin presents a two-way stop contrast cued primarily by VOT, whereas Korean presents a three-way stop contrast cued jointly by VOT and the f0 of the following vowel. Mandarin and Korean stop productions from 12 L1 Mandarin novice L2 learners of Korean were subjected to acoustic analysis. Results revealed a wide variety of production patterns, suggesting that the learning of an L2 contrast may not always be predicted by cross-language acoustic correspondences. Six of the participants were recorded again both six and 12 months later. The longitudinal results showed that some learners were unable to produce the Korean contrast in a native-like way even after one year of intensive L2 instruction. Learners whose initial production strategy was consistent but incorrect fared worse after one year than learners whose productions initially exhibited more variability. These results contribute to our understanding of both the L2 acquisition of “new” and “similar” categories and also how well naïve perceptual assimilation can predict L2 production.

Mongolian Speakers' Production and Perception of Korean Word-Initial Stops

It has long been acknowledged that Korean three-way stop distinction might be difficult to acquire for L2 whose L1 has only binary distinction in consonant categories. Given that, this study examines whether/how Mongolian L2 speakers produce Korean three-way stops in word-initial position and whether they perceive the subtle differences in phonemic status. For production and perception tasks, twenty beginner-level Mongolian of Korean participated in the experiments. First, in order to explore their L1 Mongolian influence on L2 production, we also looked into the phonetic properties of Mongolian stops. The result showed that VOT was longer for voiceless than for voiced stop, f0 of the following vowels was higher for voiced than for voiceless stops, and intensity in transition from a stop to the following vowel was higher for voiceless than for voiced stop condition. Next, Korean three-way stops were differently produced statistically in all of the phonetic correlates by Mongolian speakers. Finally, Korean lax stops were identified as either lax or tense, tense stops were most accurately identified, and aspirated ones were perceived as aspirated above the chance level. These results provide interesting implications concerning Mongolian stops and Mongolian learners acquisition of Korean stops. First, Mongolian stops may have to be differentiated in the dimension of aspiration rather than voicing. Second, Mongolian might suffer from difficulty in production and perception of Korean three-way stops due to the L1 transfer effect of two-way Mongolian stops.

Speakers of tonal and non-tonal Korean dialects use different cue weightings in the perception of the three-way laryngeal stop contrast

The current study investigated the perception of the three-way distinction among Korean voiceless stops in non-tonal Seoul and tonal Kyungsang Korean. The question addressed is whether listeners from these two dialects differ in the way they perceive the three stops. Forty-two Korean listeners (21 each from Seoul and South Kyungsang) were tested in a perception experiment with stimuli in which VOT and F0 were systematically manipulated. Analyses of the perceptual identification functions show that VOT and F0 cues trade off each other for the perception of the three stops. However, the trading relationship differs between the two dialects. Logistic regression analyses confirmed the two dialects use the perceptual cues differently for the lenis and aspirated stops. While Seoul listeners rely primarily on F0 for making lenis responses and on VOT and F0 for aspirated responses, F0 plays a less important role in modulating both lenis and aspirated responses for Kyungsang than for Seoul listeners. It is proposed that different tonal systems between the two dialects and the ongoing diachronic sound change in the stops of Seoul Korean contribute to the inter-dialect difference in cue weighting for the three-way stop distinction. The results suggest that although the difference in phonology between the two dialects influences the phonetic realization, the phonetic trade-off among multiple cues allows each dialect to maintain the phonemic distinction in a unique way.

The Perception of Korean Stops by Heritage and Non-heritage Learners: Pedagogical Implications for Beginning Learners

ABSTRACT This article presents the results from a study of the perception of three-way stop contrasts in Korean by beginning HL and non-HL of Korean. It was expected that American English learners of Korean would have difficulty perceiving the Korean stops because the three-way Korean stop contrast is not found in English. The conclusion is that early HL exposure resulted in better perceptual performance as an adult; also, bilabial stops were perceived better than velar stops or denti-alveolar stops. Pedagogically, HL leaners would need different instructional materials or pedagogical approaches from non-HL leaners. The study focused solely on perception. Nevertheless, we conclude that utilizing production-based as well as perception-based activities will help learners become more aware of the subtle differences that exist between English and Korean stop sounds.