Aspirated Stop Research Articles

Young Pashtun L1 speakers' laryngeal contrast and voicing variation in Korean word-initial stops production

While age proved to have a critical influence on learning L2 phonology, the reason behind it is yet controversial. (brain maturation, LOR, quality l2 input, crib or sequential bilingualism, etc.) This paper examines 6 young people in the same household using Pashtun as their L1. As the elder children arrived in Korea at ages 10, 8, 6, and 3 respectively, the younger two were born in Korea now aged 10 and 8. All family members have equal LOR(10 years except for the youngest), equal L1, and equal L1 and L2 use extent in the home. Examining the differences between VOT and f0 production in these young people will clarify some of the explanations behind the age effects. Moreover, the data reveals the unique L1 transfer phenomena. While Pashtun is a true voicing language, Korean is an aspirating language where all 3- way contrast stops have positive VOT values. This can lead the young people to produce word-initial Korean stops in intersonorant positions with a marked voicing-ratio and to produce allophones that neither exists in their L1 nor in L2 such as voiced aspirated stop sounds ( bɦ, d̪ɦ, gɦ). This paper will also examine whether these young people’s VOT and f0 productions would align with the current tonogenesis like sound change in Korean. This paper used picture naming tasks with easy words instead of reading non-words to not test their grapheme-phoneme correspondences. Each person produces 9 phonemes of word-initial Korean stops (3-way laryngeal contrasts in 3 POA) both in the position in isolation and carrier sentence.

Analyzing time-varying spectral characteristics of speech with function-on-scalar regression

The acoustic characteristics of noise from fricatives and stop releases are difficult to analyze. The spectral characteristics of such noise are multi-dimensional, and popular methods for analyzing them typically rely on reducing this complex information to one or a few discrete numbers, such as spectral moments or coefficients of discrete cosine transformations. In this paper, I propose using function-on-scalar regression models as a method for analyzing and mass-comparing spectra with minimal reduction of the complexity in the signal. The method is further useful for analyzing how spectra change as a function of time. The usefulness of this method is demonstrated with a corpus analysis of Danish aspirated stop releases, using the DanPASS corpus. The analysis finds that /t/ releases are invariably affricated; /k/ releases are highly affected by coarticulatory context; and /p/ releases are almost always dominated by aspiration in the latter half of the release, but are affricated in the first half in certain contexts.

Subsegmental representation in child speech production: structured variability of stop consonant voice onset time in American English and Cantonese.

Voice onset time (VOT) of aspirated stop consonants is marked by variability and systematicity in adult speech production. The present study investigated variability and systematicity of voiceless aspirated stop VOT from 161 two- to five-year-old talkers of American English and Cantonese. Overall, many aspects of child VOT productions parallel adult patterns, the analysis of which can help inform our understanding of early speech production. For instance, VOT means were comparable between children and adults, despite greater variability. Further, across children in both languages, talker-specific VOT means were strongly correlated between [th] and [kh]. This correlation may reflect a constraint of "target uniformity" that minimizes variation in the phonetic realization of a shared distinctive feature. Therefore findings suggest that target uniformity is not merely a product of a mature grammar, but may instead shape speech production representations in children as young as two years of age.

A simplification analysis of Andalusian aspirated stop clusters

Weakening or “aspiration” of syllable-final /s/ is a widespread phenomenon in Spanish. When /s/ precedes a voiceless stop in varieties with /s/-aspiration, the result is normally a pre-aspirated stop [ht]. Some speakers in southern Spain now realize /s/ + stop (sC) clusters as post-aspirated stops, particularly in Western Andalusian Spanish (WAS) [Ruch and Harrington, J. Phonics 45(1), 12 (2014)]. Previous studies have analyzed this change as a timing realignment [Parrell, J. Phonics 40(1), 37 (2012)] or articulatory overlap [Torreira, JIPA 42(1), 49 (2012)]. The current study is the first to investigate sC clusters in naturalistic data. The data consist of 34 sociolinguistic interviews with WAS speakers. Preliminary results based on 10 speakers indicate a negative correlation between closure duration and VOT, and lower overall duration of post-aspirated clusters. Affrication of /ht/ to [ts] occurred at a rate of 7%, and deletion of the vowel in 4% of /ht/ tokens in vowel-initial words (e.g., [tha] for está), a phenomenon not reported in laboratory speech. We argue that low-level gestural realignment cannot account for the naturalistic variability in sC clusters, and argue for an account involving simplification to a single post-aspirated stop.

WHY ARE LEXICAL TONES DIFFICULT TO LEARN?

AbstractL2 sounds present different kinds of challenges to learners at the phonetic, phonological, and lexical levels, but previous studies on L2 tone learning mostly focused on the phonetic and lexical levels. The present study employs an innovative technique to examine the role of prior tonal experience and musical training on forming novel abstract syllable-level tone categories. Eighty Cantonese and English musicians and nonmusicians completed two tasks: (a) AX tone discrimination and (b) incidental learning of artificial tone-segment connections (e.g., words beginning with an aspirated stop always carry a rising tone) with synthesized stimuli modeled on Thai. Although the four participant groups distinguished the target tones similarly well, Cantonese speakers showed abstract and implicit knowledge of the target tone-segment mappings after training but English speakers did not, regardless of their musical experience. This suggests that tone language experience, but not musical experience, is crucial for forming novel abstract syllable-level tone categories.

영어 음운불투명성과 탈락 모음 복원: ‘s(V)C’연속에서 기식의 발화와 인지를 중심으로

An unstressed vowel in English commonly tends to be weakened and deleted. When an unstressed vowel between [s] and a voiceless stop as in ‘s(V)CV’ is deleted, phonological opacity might arise since a voiceless stop would be aspirated before a stressed vowel, and English prohibits such a sequence of [s] and an aspirated stop. The goals of this study are to investigate whether such phonological opacity virtually arises in English and to see how English native speakers deal with the opacity and perceive the words correctly. Results showed that schwa deletion resulted in phonological opacity with respect to aspiration. English speakers, however, had little problem restoring the deleted vowel and could resolve the opacity by means of VOT that played a very crucial role as an acoustic cue in the processes.

Influence of coda stop features on perceived vowel duration

Four experiments tested what cues contribute to English speakers’ perception of vowel duration. Listeners categorized the duration of vowels as ‘long’ or ‘short’ for stimuli produced with voiced, voiceless, breathy voiced, or voiceless aspirated stop codas. Listeners demonstrated a strong ability to perceive vowel duration, though perception was continuous rather than categorical. There were several interacting factors influencing perceived vowel duration, based on expectations set by the presence of particular codas and also acoustic effects of the coda on the vowel. When the coda was removed, vowels that had been produced before voiced codas were perceived as longer than vowels produced before voiceless codas, though they exhibited the opposite effect when codas were present. Vowels were also perceived as longer when produced before breathy voiced stops, regardless of whether or not the stop was present. The steeper f0 falls associated with voiced codas within these stimuli likely contributed to the longer perceived duration of vowels from this environment; manipulating f0 contours eliminated effects of the original coda on perceived vowel duration. The effects of the production environment on perceived vowel duration suggest a possible perceptual pathway for the voicing effect on vowel duration.

Kashaya [asp] assimilation and dissimilation by correspondence

An aspirated stop in a Kashaya prefix becomes a plain voiceless stop by dissimilation when the root begins with an aspirate; but it also assimilates to an unaspirated stop in the same position. The OCP cannot help with assimilation, so I propose a unified analysis of the two phenomena within Agreement by Correspond­ence (Rose & Walker 2004, Bennett 2013). Unlike somewhat similar cases in the literature with both assimilation and dissimilation, here there is no structural difference. I posit a conjoined constraint that penalizes an initial aspirate in a correspondence relation; the rest follows from standard ABC assumptions.

Adaptation of English stops into Mandarin Chinese

This study investigates the adaptation of English stops into Mandarin Chinese. English stops have a binary [±voice] contrast, whereas Mandarin Chinese stops are distinguished by aspiration. A corpus study based on 720 English loanwords shows that English voiced stops are mapped to the unaspirated stops in Mandarin Chinese while English voiceless stops are mapped to the aspirated stops in Mandarin Chinese, regardless of whether the English stops are aspirated or unaspirated. This finding is in favor of the phonological view on loanword adaptation in that phonemic contrast in the source language is maintained through one-to-one mapping between the source sounds and the loan sounds. However, the English bilabial aspirated stop [ph] is mapped to either the aspirated or unaspirated bilabial stop in Mandarin Chinese. Further, the English velar stop before a high front vowel is mapped to the Mandarin Chinese affricate. Such mappings differ from the general pattern and can be explained by perceptual similarity based on VOT between the source sounds and the loan sounds. We draw a conclusion that both faithful phonological contrast and perceptual similarity work together for the adaptation of English stops into Mandarin Chinese. (Qingdao University of Science and Technology · Chonnam National University)

The Production of English Aspirated Stops in Foreign Language Acquisition

The Production of English Aspirated Stops in Foreign Language Acquisition

Effects of Age, Sex and Syllable Number on Voice Onset Time: Evidence from Children's Voiceless Aspirated Stops.

Voice onset time (VOT) is a temporal acoustic parameter that reflects motor speech coordination skills. This study investigated the patterns of age and sex differences across development of voice onset time in a group of 70 English-speaking children, ranging in age from 4.1 to 18.4 years, and 12 young adults. The effect of the number of syllables on VOT patterns was also examined. Speech samples were elicited by producing syllables /pa/ and /pataka/. Results supported previous findings showing that younger children produce longer VOT values with higher levels of variability. Markedly higher VOT values and increased variability were found for boys at ages between 8 and 11 years, confirming sex differences in VOT patterns and patterns of variability. In addition, all participants consistently produced shorter VOT with higher variability for multisyllables than monosyllables, indicating an effect of syllable number. Possible explanations for these findings and clinical implications are discussed.

Coarticulation of non-modal phonation.

Although there are many studies on the acoustics of phonation, few deal specifically with the coarticulation of non-modal phonations. Using data from three languages (English, White Hmong, and Korean), this project describes the acoustics of breathy-to-creaky phonation contours in vowels. In English, such contours are found in vowels preceded by [h] or an aspirated stop, and followed by a preglottalized coda-stop, e.g., “cat.” In Hmong, the contours are found in vowels with a phonemic creaky tone that are preceded by an aspirated stop or [h]. In Korean, the contours are derived from vowels preceded by an aspirated or lenis stop and followed by a coda-stop, which is found to show preglottalization. Twelve speakers of each language were recorded saying monosyllables with expected phonation contours in carrier sentences. The phonation was analyzed using VOICESAUCE [Shue et al. (2009)], which outputs a value at each millisecond for several acoustic measures. Time courses for measures like H1*-H2* and harmonics-to-noise ratio show support for the presence of breathy-creaky contours in the three languages. I analyze the cross-linguistic differences in the timing of the contours in light of previous findings on the timing of non-modal phonation [e.g., Blankenship (2002)] and current theories of coarticulation.

The relation between articulatory and aerodynamic properties of single /t/, /S/ and their combination in /tS/ and /St/

Intraoral pressure changes during speech production are a result of different factors, such as articulatory movements (place and manner of articulation), subglottal pressure, and laryngeal‐oral coordination. This study attempts to provide a better understanding of the relation between aerodynamics and articulation in single voiceless consonants and their combinations. We gathered electropalatographic data simultaneously with intraoral pressure data for 9 native speakers of German. During voiceless aspirated stop production intraoral pressure equalizes with subglottal pressure since an oral closure is formed and the glottis is open. During voiceless fricative production intraoral pressure is lower than in stop production since the air can escape through the oral constriction. In /t, S, St/ the intraoral pressure changes are highly correlated with the articulatory behaviour. However, the affricate /tS/ shows an unusual relationship with aerodynamics and articulation. Although an oral closure is formed, pressure rises at a later point and reaches its peak during the fricative. We interpret these findings with respect to a special laryngeal ‐ oral coordination in affricates as reported in Hoole et al. (2003) who found a relatively late glottal opening during the stop portion of the affricate.

Effects of consonant aspiration on Mandarin tones

In this paper we present an experiment on the influence of consonant aspiration in Mandarin. A minimal pair, /da/ and /ta/, which differ only in aspiration, are produced in carrier sentences by native speakers of Mandarin. It is found that consonant aspiration affects the fundamental frequency (F0) of the following vowel. The onset F0 of a tone is higher following unaspirated consonants than following aspirated consonants, and the magnitude of difference is related to both the current and preceding tones. However, the later part of a tone tends to be lower following an unaspirated consonant than an aspirated one. These results seem to favor the speech aerodynamic model proposed by Ohala (1976), which predicts a smaller value of airflow at the onset of the vowel following an aspirated stop than an unaspirated one. The current results, however, seem to provide further details about the mechanism of the aerodynamic effect. Additionally, results of detailed analyses seem to suggest a possible source of the existing controversies over the exact effect of aspiration on F0. The discrepancy in the previously reported effects may be partially due to the difference in how the first few vocal cycles of the vowel are measured in different studies.

Intrinsic effects of obstruent consonants on F0

This study is part of a project to improve generation of F0 contours in rule-based speech synthesis using HLsyn. When a vowel follows an obstruent consonant, the fundamental frequency in the first few tens of milliseconds of the vowel is influenced by the voicing characteristics of the consonant. In an attempt to model this influence, pilot data were recorded by one subject. The alveolar stops /d,t,th/ and the nasal /m/ were paired with the vowels /i,a/ to form CVm syllables. The syllables mVm served as a baseline with which to compare the stop consonants. The target syllables were embedded in carrier sentences. Intonation was varied so that each target syllable was produced with either a H*, L*, or no pitch accent. F0 was increased relative to the baseline following all three obstruents, with the greatest increase for the voiceless aspirated stop and the least for the voiced stop. The F0 increase and the disparity among the three stops varied with pitch accent: H* showed the greatest influence, while L* showed the least. F0 may be increased for up to 80 ms following voicing onset. Data will be presented for additional subjects and obstruents. [Work supported by NIH Grant No. DC04331.]

The phonetic nature of “voiceless” nasals in Pokomo: Implications for sound change

Several of the diachronic seriations proposed for Bantu languages assume a relatively early process of nasal devoicing which preceded, and set the stage for, development of stop aspiration (e.g., Kerremans 1980; Hinnebusch, Nurse and Mould 1981). Maddieson (1991) has argued convincingly that one synchronic reflex, an aspirated nasal in Sukuma, may have developed without an intervening stage involving a voiceless nasal. However, reflexes reportedly involving voiceless nasals or nasal loss might still be thought to motivate a seriation that posits a stage with voiceless nasals. We will argue that even these reflexes need not have developed from an intervening stage in which the nasal was phonologically voiceless. For one thing, developments in feature theory argue against representations which posit a phonologically voiceless nasal and following aspirated stop. Furthermore, our phonetic data on Pokomo suggest that nasal voicelessness can result from a phonetic effect - temporal overlap between the nasal and the aspiration gesture for the following stop. We propose that changes in phonetic detail such as the magnitude and timing of gestures produced nasal voicelessness or partial voicelessness, phonetic conditions which led to phonological restructuring in many of the Bantu languages.

Laryngeal complexity in Otomanguean vowels

Linguistic sound systems necessarily possess contrastive values that are sufficiently distinct from one another that their individual characters may be learned by the listener. In this way, any given value in any given system fulfils its functional role of rendering forms distinct which differ in meaning. Articulatory, aerodynamic, acoustic and auditory constraints serve to mediate between such sound–meaning correspondences in non-trivial ways. Indeed, if it can be shown that the sound patterns of language are in part explainable by these physical systems, then students of linguistic sound systems would do well to study in detail the phonetic base. Consider an example case. Laryngeal gestures and supralaryngeal gestures are by and large articulatorily independent of each other. Thus, for example, a voiceless aspirated stop consists of an oral occlusion, cued by silence, as well as an articulatorily independent laryngeal abduction, cued by broadband noise. Were the phonetic realisation of these two gestures strictly simultaneous, the cues signalling the laryngeal abduction would not be perceived as such by the listener (*[ot]). A listener can tell that there is no voicing, but cannot recover more specific information regarding the state of the glottis during oral closure. Stated simply, the full closure here reduces the acoustic output to zero. With zero acoustic energy, no source information other than silence is transmitted to the listener. However, upon staggering the two gestures, the otherwise obscured information is rendered salient.

Locus equations as phonetic descriptors of consonantal place of articulation.

This experiment tested whether locus equation coefficients, slope, and y-intercept could serve as indices of place of articulation for obstruents sharing the same place of articulation across different manner classes. Locus equations for 22 speakers were derived from CV/t/ words with initial voiced stop /d/, voiceless aspirated stop /t/, nasal /n/, voiced fricative /z/, and voiceless fricative /s/ preceding 10 vowel contexts. Post hoc tests revealed /d/ = /z/ = /n/ for slope means. Voiced /d/ and voiceless /t/ were also equivalent when F2 transition onset measurement points were equated. Scatterplots of locus equation coefficients revealed three nonoverlapping and distinct clusters when the diverse coronal group was compared with labials and velars. A discriminant analysis using slope and y-intercept as predictors successfully categorized all five coronals into one alveolar group with 87.1% accuracy. The collective results support the contention that locus equations can serve as effective phonetic descriptors of consonant place of articulation across manner classes.

Locus equations as phonetic descriptors of consonantal place of articulation

This experiment tested whether locus equation coefficients, slope, and y intercept could serve as indices of place of articulation for obstruents sharing the same place of articulation across different manner classes. A previous study [C. A. Fowler, Percept. Psychophys. 55, 597–610 (1994)] reported that locus equations provided poor information for place because the mean slope for /d/ (0.47) was found to be statistically different than the mean slope for /z/ (0.42) across ten speakers. Locus equations from 22 speakers were derived from CV/t/ words with initial voiced oral stop /d/, voiceless aspirated stop /th/, nasal stop /n/, voice fricative /z/, and voiceless fricative /s/ preceding ten vowel contexts. Post-hoc tests revealed /d/=/z/=/n/ for slope means. Slopes for /d/ and /th/ were also equivalent when F2 onset measurement points were corrected to account for aspiration. Scatterplots of slopes × y intercepts revealed three nonoverlapping and distinct clusters of coordinates when the coronal group (/d, t, n, z, s/) was plotted versus labials and velars. A discriminant analysis using slope and y intercept successfully categorized all coronals as alveolars with 87.1% accuracy. The collective results support the contention that locus equations can serve as effective descriptors of consonant place of articulation across manner classes. [Work supported by NIH.]

Incorporating aerodynamic and laryngealcomponents into task dynamics

Aerodynamic and laryngeal components were added to the task-dynamic model to make it a more complete model of speech production. New tract variables included were subglottal pressure, transglottal pressure, and a quantity giving fundamental frequency in sonorant conditions. New articulators included total force on the lungs, generalized laryngeal tension, and supralaryngeal volume. Simulations of /VCV/ sequences, where C was either a voiced or a voiceless aspirated stop, demonstrated the usefulness of these additions.