Data on English coda voicing contrast under different prosodic conditions produced by American English speakers and Korean learners of English.

This data article provides acoustic data for individual speakers' production of coda voicing contrast between stops in English, which are based on laboratory speech recorded by twelve native speakers of American English and twenty-four Korean learners of English. There were four pairs of English monosyllabic target words with voicing contrast in the coda position (bet-bed, pet-ped, bat-bad, pat-pad). The words were produced in carrier sentences in which they were placed in two different prosodic boundary conditions (Intonational Phrase initial and Intonation Phrase medial), two pitch accent conditions (nuclear-pitch accented and unaccented), and three focus conditions (lexical focus, phonological focus and no focus). The raw acoustic measurement values that are included in a CSV-formated file are F0, F1, F2 and duration of each vowel preceding a coda consonant; and Voice Onset Time of word-initial stops. This article also provides figures that exemplify individual speaker variation of vowel duration, F0, F1 and F2 as a function of focus conditions. The data can thus be potentially reused to observe individual variations in phonetic encoding of coda voicing contrast as a function of the aforementioned prosodically-conditioned factors (i.e., prosodic boundary, pitch accent, focus) in native vs. non-native English. Some theoretical aspects of the data are discussed in the full-length article entitled "Phonetic encoding of coda voicing contrast under different focus conditions in L1 vs. L2 English" [1].

Prosodic Structural Effects on Non-Contrastive Coarticulatory Vowel Nasalization in L2 English by Korean Learners.

This acoustic study explores how Korean learners produce coarticulatory vowel nasalization in English that varies with prosodic structural factors of focus-induced prominence and boundary. N-duration and A1-P0 (degree of V-nasalization) are measured in consonant-vowel-nasal (CVN) and nasal-vowel-consonant (NVC) words in various prosodic structural conditions (phrase-final vs. phrase-medial; focused vs. unfocused). Korean learners show a systematic fine-tuning of the non-contrastive V-nasalization in second language (L2) English in relation to prosodic structure, although it does not pertain to learning new L2 sound categories (i.e., L2 English nasal consonants are directly mapped onto Korean nasal consonants). The prosodic structurally conditioned phonetic detail in English appears to be accessible in most part to Korean learners and was therefore reflected in their production of L2 English. Their L2 production, however, is also found to be constrained by their first language (L1-Korean) to some extent, resulting in some phonetic effects that deviate from both L1 and L2. The results suggest that the seemingly low-level coarticulatory process is indeed under the speaker's control in L2, which reflects interactions of the specificities of the phonetics-prosody interface in L1 and L2. The results are also discussed in terms of their implications for theories of L2 phonetics.

Production of coda voicing contrast of L2 English by native Mandarin Chinese speakers in comparison with native Korean speakers.

This study investigates native language effects on phonetic encoding of coda voicing contrast in L2 English by Chinese versus Korean speakers. Results show much smaller phonetic differences in both vowel duration and F0 in marking coda voicing contrast for Chinese speakers than Korean speakers, despite native Chinese speakers' experience with lexical tones. They suggest that producing an F0-related cue in L2 is conditioned by position-specific phonological richness and use of F0 in the speaker's L1. The results are discussed in terms of contrast maximization and effort minimization with reference to the information structure occurring in both L1 and L2.

Glottal stops do not constrain lexical access as do oral stops.

This study explores processing characteristics of a glottal stop in Maltese which occurs both as a phoneme and as an epenthetic stop for vowel-initial words. Experiment 1 shows that its hyperarticulation is not necessarily mapped onto an underlying form, although listeners may interpret it as underlying at a later processing stage. Experiment 2 shows that listeners' experience with a particular speaker's use of a glottal stop exclusively as a phoneme does not modulate competition patterns accordingly. Not only are vowel-initial words activated by [ʔ]-initial forms, but /ʔ/-initial words are also activated by vowel-initial forms, suggesting that lexical access is not constrained by an initial acoustic mismatch that involves a glottal stop. Experiment 3 reveals that the observed pattern is not generalizable to an oral stop /t/. We propose that glottal stops have a special status in lexical processing: it is prosodic in nature to be licensed by the prosodic structure.

Data on preboundary lengthening in Tokyo Japanese as a function of prosodic prominence, boundary, lexical pitch accent and moraic structure.

This article provides individual speakers' acoustic durational data on preboundary (phrase-final) lengthening in Japanese. The data are based on speech recorded from fourteen native speakers of Tokyo Japanese in a laboratory setting. Each speaker produced Japanese disyllabic words with four different moraic structures (CVCV, CVCVN, CVNCV, and CVNCVN, where C stands for a non-nasal onset consonant, V for a vowel, and N for a moraic nasal coda) and two pitch accent patterns (initially-accented and unaccented). The target words were produced in carrier sentences in which they were placed in two different prosodic boundary conditions (Intonational Phrase-final ('IPf') and Intonational Phrase-medial ('IPm')) and two focus contexts (focused and unfocused). The measured raw values of acoustic duration of each segment in different conditions are included in a CSV-formatted file. Another CSV-formatted file is provided with numeric calculations in both absolute and relative terms that exhibit the magnitude of preboundary lengthening across different prominence contexts (focused/unfocused and initially-accented/unaccented). The absolute durational difference was obtained as a numeric increase of preboundary lengthening of each segment produced in phrase-final position versus phrase-medial position (i.e., Δ(IPf-IPm) where 'f' = 'final' and 'm' = 'medial'). The relative durational difference was obtained as a percentage increase of preboundary lengthening in IP-final position versus IP-medial position, which was calculated by the absolute durational difference divided by the duration of the segment in phrase-medial position and then multiplied by 100 (i.e., (Absolute difference/IPm)*100). This article also provides figures that exemplify speaker variation in terms of absolute and relative differences of preboundary lengthening as a function of pitch accent. Some theoretical aspects of the data are discussed in the full-length article entitled "Preboundary lengthening in Japanese: To what extent do lexical pitch accent and moraic structure matter?" [1].

The Role of Segmental Information in Syntactic Processing Through the Syntax-Prosody Interface.

In two experiments, it was investigated whether potentially contrastive segmental information in the form of an epenthetic glottal stop in Maltese can influence syntactic parsing decisions. The glottal stop in Maltese serves a dual function as a phoneme used for lexical contrast and a non-contrastive phone that may mark a prosodic juncture. In both experiments, participants perceived a larger prosodic boundary before the word u (Engl. "and") if the u was produced with an epenthetic glottal stop, showing the use of prosodically conditioned segmental information in syntactic parsing. Furthermore, listeners were generally unaware of the existence of the epenthetic glottal stop even though a glottal stop is used as a phoneme represented as a grapheme "q." They also perceived a larger prosodic juncture when the preceding syllable was lengthened before the word u ("and"). These findings were consistent regardless of whether the glottal stop reinforced a late-closure decision (Experiment 1) or an early-closure decision (Experiment 2). The results indicate that both segmental and suprasegmental information influences syntactic parsing decisions, demonstrating that the syntax-prosody interface is reflected along both the segmental and suprasegmental (duration) dimensions, which are mediated by the phonetics-prosody interface.

Prosodic structurally conditioned variation of coarticulatory vowel nasalization in Mandarin Chinese: Its language specificity and cross-linguistic generalizability.

This study compares prosodic structural effects on nasal (N) duration and coarticulatory vowel (V) nasalization in NV (Nasal-Vowel) and CVN (Consonant-Vowel-Nasal) sequences in Mandarin Chinese with those found in English and Korean. Focus-induced prominence effects show cross-linguistically applicable coarticulatory resistance that enhances the vowel's phonological features. Boundary effects on the initial NV reduced N's nasality without having a robust effect on V-nasalization, whose direction is comparable to that in English and Korean. Boundary effects on the final CVN showed language specificity of V-nasalization, which could be partly attributable to the ongoing sound change of coda nasal lenition in Mandarin.

An apparent-time study of an ongoing sound change in Seoul Korean: A prosodic account.

In present-day Seoul Korean, the primary phonetic feature for the lenis-aspirated stop distinction is shifting from VOT to F0. Some previous studies have considered this sound change to be a tonogenesis, whereby the low-level F0 perturbation has developed into tonal features (L for the lenis and H for the aspirated) in the segmental phonology. They, however, have examined the stop distinction only at a phrase- or utterance-initial position. We newly explore the sound change in relation to various prosodic structural factors (position and prominence). Apparent-time production data were recorded from four speaker groups: young female, young male, old female, old male. The way the speakers use VOT versus F0 indeed varies as a function of position and prominence. Crucially, in all groups, VOT is still used for the lenis-aspirated distinction phrase-medially due to the lenis stop voicing. This role of VOT, however, is found only in the non-prominent (unfocused) condition, in which the F0 difference is reduced to a low-level perturbation effect. In the prominent (focused) context in which tones come into play, the role of VOT diminishes, led by young female speakers. These can be interpreted as a prosodically-conditioned, complementary use of the features to maintain sufficient contrast. Importantly, however, the tonal difference under focus is not bidirectionally polarized, so that F0 is not lowered for the lenis stop. A lack of direct enhancement of the distinctive L tone weakens a possibility that F0 is transphonologized to the phonemic feature system of the language. As an alternative to the view that tonal features are newly introduced in the segmental phonology, we propose a prosodic account: the sound change is best characterized as a prosodically-conditioned change in the use of the segmental voicing feature (implemented by VOT) versus already available post-lexical tones in the intonational phonology of Korean.

Datasets on the production and perception of underlying and epenthetic glottal stops in Maltese.

This article provides some supplementary analysis data of speech production and perception of glottal stops in the Semitic language Maltese. In Maltese, a glottal stop can occur as a phoneme, but also as a phonetic marker of vowel-initial words (as in the case with Germanic languages like English). Data from four experiments are provided, which will allow other researchers to reproduce the results and apply their own data-analysis techniques to these data for further data exploration. A production experiment (Experiment 1) investigates how often the glottal marking of vowel-initial words occurs (causing vowel-initial words to be ambiguous with words starting with a glottal stop as a phoneme) and whether the glottal gesture for this marking can be differentiated from an underlying (phonemic) glottal stop in its acoustic properties. Experiments 2 to 4 investigate how and to what extent Maltese listeners perceive glottal markings as lexical (phonemic) or epenthetic (phonetic), using a two-alternative forced choice task (Experiment 2), a visual-world eye tracking task with printed target words (Experiment 3) and a gating task (Experiment 4). A full account of theoretical consequences of these data can be found in the full length article entitled "The glottal stop between segmental and suprasegmental processing: The case of Maltese" [1].

Preboundary lengthening in Japanese: To what extent do lexical pitch accent and moraic structure matter?

In this acoustic study, preboundary lengthening (PBL) in Japanese is investigated in relation to the prosodic structure in disyllabic words with different moraic and pitch accent distributions. Results showed gradient progressive PBL effects largely independent of the mora count. The domain of PBL is better explained by the syllable structure than the moraic structure. PBL, however, is attracted toward a non-final moraic nasal, showing some role of the mora. The initial pitch accent does not attract PBL directly, but it suppresses PBL of the final rime as a way of maintaining the relative prominence, showing a language-specific PBL modulation.

Voice Onset Time and beyond: Exploring laryngeal contrast in 19 languages.

In this special collection entitled Marking 50 Years of Research on Voice Onset Time and the Voicing Contrast in the World's Languages, we have compiled eleven studies investigating the voicing contrast in 19 languages. The collection provides extensive data obtained from 270 speakers across those languages, examining VOT and other acoustic, aerodynamic and articulatory measures. The languages studied may be divided into four groups: 'aspirating' languages with a two-way contrast (English, three varieties of German); 'true voicing' languages with a two-way contrast (Russian, Turkish, Brazilian Portuguese, two Iranian languages Pashto and Wakhi); languages with a three-way contrast (Thai, Vietnamese, Khmer, Yerevan Armenia, three Indo-Aryan languages, Dawoodi, Punjabi and Shina, and Burushaki spoken in India); and Indo-Aryan languages with a more than three-way contrast (Jangli and Urdu with a four-way contrast, and Sindhi and Siraiki with a five-way contrast). We discuss the cross-linguistic data, focusing on how much VOT alone tell s us above the voicing contrast in these languages, and what other phonetic dimensions (such as consonant-induced F0 and voice quality) are needed for a complete understanding of laryngeal contrast in these languages. Implications for various issues emerge: universal phonetic feature systems, effects of language contact on linguistic levelling, and the relation between laryngeal contrast and supralaryngeal articulation. The cross-linguistic VOT data also lead us to discuss how the distribution of VOT as measured acoustically may allow us to infer the underlying articulation and how it might be approached in gestural phonologies. The discussion on these multiple issues sparks new questions to be resolved, and provide indications of where the field may be best directed in exploring laryngeal contrast in voicing in the world's languages.

Stop voicing contrast in American English: Data of individual speakers in trochaic and iambic words in different prosodic structural contexts.

The data reported in this article contain eleven (6 female and 5 male) individual speaker's speech production patterns for the word-initial voiced and voiceless stops (/p,t/ and /b,d/) in American English. The production patterns are documented in the acoustic parameter: the Integrated Voicing Index (IVI) obtained from Voice Onset Time (VOT) and voicing duration in the stop closure (Voicing-in-Closure), in various prosodic contexts: lexically-stressed vs. unstressed; accented (focused) vs. unaccented (unfocused); phrase-initial vs. phrase-medial. The data also contain a CVS file with each speaker׳s mean values of the IVI, VOT and Voicing-in-Closure for each prosodic condition for the voiced and voiceless stops, along with the information about the speaker gender. For further discussion of the data, please refer to the full length article entitled "Prosodic-structural modulation of stop voicing contrast along the VOT continuum in trochaic and iambic words in American English" (Kim et al., 2018).

Focus and boundary effects on coarticulatory vowel nasalization in Korean with implications for cross-linguistic similarities and differences.

This study investigates focus and boundary effects on Korean nasal consonants and vowel nasalization. Under focus, nasal consonants lengthen in CVN# but shorten in #NVC, enhancing [nasal] vs [oral]. Vowels resist nasalization under focus, enhancing [oral]. Domain-initial nasal consonants denasalize, exercising no coarticulatory influence. Domain-final nasal consonants shorten counter to expectation, although vowel nasalization increases. Comparison with English data reveals similarities (focus-induced coarticulatory resistance) despite cross-linguistic differences in marking prominence, but it also suggests that prosodic-structural conditioning of non-contrastive vowel nasalization, albeit based on phonetic underpinnings of coarticulatory process, is fine-tuned in language-specific ways, resulting in cross-linguistic variation.

A time course of prosodic modulation in phonological inferencing: The case of Korean post-obstruent tensing.

Application of a phonological rule is often conditioned by prosodic structure, which may create a potential perceptual ambiguity, calling for phonological inferencing. Three eye-tracking experiments were conducted to examine how spoken word recognition may be modulated by the interaction between the prosodically-conditioned rule application and phonological inferencing. The rule examined was post-obstruent tensing (POT) in Korean, which changes a lax consonant into a tense after an obstruent only within a prosodic domain of Accentual Phrase (AP). Results of Experiments 1 and 2 revealed that, upon hearing a derived tense form, listeners indeed recovered its underlying (lax) form. The phonological inferencing effect, however, was observed only in the absence of its tense competitor which was acoustically matched with the auditory input. In Experiment 3, a prosodic cue to an AP boundary (which blocks POT) was created before the target using an F0 cue alone (i.e., without any temporal cues), and the phonological inferencing effect disappeared. This supports the view that phonological inferencing is modulated by listeners' online computation of prosodic structure (rather than through a low-level temporal normalization). Further analyses of the time course of eye movement suggested that the prosodic modulation effect occurred relatively later in the lexical processing. This implies that speech processing involves segmental processing in conjunction with prosodic structural analysis, and calls for further research on how prosodic information is processed along with segmental information in language-specific vs. universally applicable ways.

Articulatory characteristics of preboundary lengthening in interaction with prominence on tri-syllabic words in American English.

This study investigated articulation of preboundary lengthening (PBL) in tri-syllabic pseudo words (bábaba, babába, bababá) in American English. Results from 10 speakers showed that PBL was modulated by the degree of prominence, i.e., the less prominent, the more PBL. PBL was attracted to the penultimate stressed syllable but only when the word received no pitch accent whereas the antepenultimate syllable showed no PBL. Kinematically, PBL was accompanied by a larger movement along with an increase in peak velocity, showing a kind of boundary-related articulatory strengthening, although there was some evidence of temporal expansion possibly due to lowered stiffness.

Experience with a second language affects the use of fundamental frequency in speech segmentation.

This study investigates whether listeners' experience with a second language learned later in life affects their use of fundamental frequency (F0) as a cue to word boundaries in the segmentation of an artificial language (AL), particularly when the cues to word boundaries conflict between the first language (L1) and second language (L2). F0 signals phrase-final (and thus word-final) boundaries in French but word-initial boundaries in English. Participants were functionally monolingual French listeners, functionally monolingual English listeners, bilingual L1-English L2-French listeners, and bilingual L1-French L2-English listeners. They completed the AL-segmentation task with F0 signaling word-final boundaries or without prosodic cues to word boundaries (monolingual groups only). After listening to the AL, participants completed a forced-choice word-identification task in which the foils were either non-words or part-words. The results show that the monolingual French listeners, but not the monolingual English listeners, performed better in the presence of F0 cues than in the absence of such cues. Moreover, bilingual status modulated listeners' use of F0 cues to word-final boundaries, with bilingual French listeners performing less accurately than monolingual French listeners on both word types but with bilingual English listeners performing more accurately than monolingual English listeners on non-words. These findings not only confirm that speech segmentation is modulated by the L1, but also newly demonstrate that listeners' experience with the L2 (French or English) affects their use of F0 cues in speech segmentation. This suggests that listeners' use of prosodic cues to word boundaries is adaptive and non-selective, and can change as a function of language experience.

Phonetic Encoding of Coda Voicing Contrast under Different Focus Conditions in L1 vs. L2 English.

This study investigated how coda voicing contrast in English would be phonetically encoded in the temporal vs. spectral dimension of the preceding vowel (in vowel duration vs. F1/F2) by Korean L2 speakers of English, and how their L2 phonetic encoding pattern would be compared to that of native English speakers. Crucially, these questions were explored by taking into account the phonetics-prosody interface, testing effects of prominence by comparing target segments in three focus conditions (phonological focus, lexical focus, and no focus). Results showed that Korean speakers utilized the temporal dimension (vowel duration) to encode coda voicing contrast, but failed to use the spectral dimension (F1/F2), reflecting their native language experience-i.e., with a more sparsely populated vowel space in Korean, they are less sensitive to small changes in the spectral dimension, and hence fine-grained spectral cues in English are not readily accessible. Results also showed that along the temporal dimension, both the L1 and L2 speakers hyperarticulated coda voicing contrast under prominence (when phonologically or lexically focused), but hypoarticulated it in the non-prominent condition. This indicates that low-level phonetic realization and high-order information structure interact in a communicatively efficient way, regardless of the speakers' native language background. The Korean speakers, however, used the temporal phonetic space differently from the way the native speakers did, especially showing less reduction in the no focus condition. This was also attributable to their native language experience-i.e., the Korean speakers' use of temporal dimension is constrained in a way that is not detrimental to the preservation of coda voicing contrast, given that they failed to add additional cues along the spectral dimension. The results imply that the L2 phonetic system can be more fully illuminated through an investigation of the phonetics-prosody interface in connection with the L2 speakers' native language experience.

Effects of L1 prosody on segmental contrast in L2: The case of English stop voicing contrast produced by Korean speakers.

This study investigated how the L1 phonetics-prosody interface transfers to L2 by examining prosodic strengthening effects (due to prosodic position and focus) on English voicing contrast (bad-pad) as produced by Korean vs English speakers. Under prosodic strengthening, Korean speakers showed a greater F0 difference due to voicing than English speakers, suggesting that their experience with the macroprosodic use of F0 in Korean transfers into L2. Furthermore, Korean speakers produced voiced stops with low F0 and short voice onset time as English speakers did, although such a cue pairing is absent in Korean, showing dissociation of cues from L1 segments for L2 production.

Individual differences in perceptual adaptability of foreign sound categories.

Listeners possess a remarkable ability to adapt to acoustic variability in the realization of speech sound categories (e.g., different accents). The current work tests whether non-native listeners adapt their use of acoustic cues in phonetic categorization when they are confronted with changes in the distribution of cues in the input, as native listeners do, and examines to what extent these adaptation patterns are influenced by individual cue-weighting strategies. In line with previous work, native English listeners, who use voice onset time (VOT) as a primary cue to the stop voicing contrast (e.g., 'pa' vs. 'ba'), adjusted their use of f0 (a secondary cue to the contrast) when confronted with a noncanonical "accent" in which the two cues gave conflicting information about category membership. Native Korean listeners' adaptation strategies, while variable, were predictable based on their initial cue weighting strategies. In particular, listeners who used f0 as the primary cue to category membership adjusted their use of VOT (their secondary cue) in response to the noncanonical accent, mirroring the native pattern of "downweighting" a secondary cue. Results suggest that non-native listeners show native-like sensitivity to distributional information in the input and use this information to adjust categorization, just as native listeners do, with the specific trajectory of category adaptation governed by initial cue-weighting strategies.

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.