Voice Onset Time Differences Research Articles

What do you learn from a single cue? Dimensional reweighting and cue reassociation from experience with a newly unreliable phonetic cue

In language comprehension, we use perceptual cues to infer meanings. Some of these cues reside on perceptual dimensions. For example, the difference between bear and pear is cued by a difference in voice onset time (VOT), which is a continuous perceptual dimension. The present paper asks whether, and when, experience with a single value on a dimension behaving unexpectedly is used by the learner to reweight the whole dimension. We show that learners reweight the whole VOT dimension when exposed to a single VOT value (e.g., 45 ms) and provided with feedback indicating that the speaker intended to produce a /b/ 50% of the time and a /p/ the other 50% of the time. Importantly, dimensional reweighting occurs only if 1) the 50/50 feedback is unexpected for the VOT value, and 2) there is another dimension that is predictive of feedback. When no predictive dimension is available, listeners reassociate the experienced VOT value with the more surprising outcome but do not downweight the entire VOT dimension. These results provide support for perceptual representations of speech sounds that combine cues and dimensions, for viewing perceptual learning in speech as a combination of error-driven cue reassociation and dimensional reweighting, and for considering dimensional reweighting to be reallocation of attention that occurs only when there is evidence that reallocating attention would improve prediction accuracy (Harmon, Z., Idemaru, K., & Kapatsinski, V. 2019. Learning mechanisms in cue reweighting. Cognition, 189, 76–88.).

Exploring the impact of type II diabetes mellitus on voice quality.

This cross-sectional study aimed to investigate the potential of voice analysis as a prescreening tool for type II diabetes mellitus (T2DM) by examining the differences in voice recordings between non-diabetic and T2DM participants. 60 participants diagnosed as non-diabetic (n = 30) or T2DM (n = 30) were recruited on the basis of specific inclusion and exclusion criteria in Iran between February 2020 and September 2023. Participants were matched according to their year of birth and then placed into six age categories. Using the WhatsApp application, participants recorded the translated versions of speech elicitation tasks. Seven acoustic features [fundamental frequency, jitter, shimmer, harmonic-to-noise ratio (HNR), cepstral peak prominence (CPP), voice onset time (VOT), and formant (F1-F2)] were extracted from each recording and analyzed using Praat software. Data was analyzed with Kolmogorov-Smirnov, two-way ANOVA, post hoc Tukey, binary logistic regression, and student t tests. The comparison between groups showed significant differences in fundamental frequency, jitter, shimmer, CPP, and HNR (p < 0.05), while there were no significant differences in formant and VOT (p > 0.05). Binary logistic regression showed that shimmer was the most significant predictor of the disease group. There was also a significant difference between diabetes status and age, in the case of CPP. Participants with type II diabetes exhibited significant vocal variations compared to non-diabetic controls.

An Experimental Study on Societal Factors Affecting VOT of English Plosives

Plosives are integral components of English consonants. In phonetics, English plosives are classified into voiceless plosives /p, t, k/ and /b, d, g/. VOT (voice onset time) was defined as “the time interval between the burst that marks release of the stop closure and the onset of quasi-periodicity that reflects laryngeal vibration”. VOT is a significant acoustic feature and analytic parameter of plosives. Referring to Labov’s experimental model of linguistic variation analysis, this study investigates the influences of societal factors have on the VOT of English plosives.In this study, 15 English words with word-initial voiceless plosives /p, t, k/ and 15 word-initial voiced plosives /b, d, g/ were selected as reading material; meanwhile, 30 subjects were randomly recruited to read, and audio samples were collected. It is found that the two social factors (gender and regional dialect) selected in this experiment have influences in different degrees on the English plosive VOT of the subjects. The specific results are as follows.For gender, no significant difference exists between males and females, but the mean VOT of females is longer than that of males, which is basically consistent with previous research results. The underlying reasons of the gender VOT differences inferred by this paper can be physiological and sociophonetical. For regional dialects, the VOT of the subjects were primarily influenced by Southwest Mandarin and Min Dialect, in which the mean value of voiceless plosives was higher and the difference was greater for speakers of Southwest Mandarin, and the mean value of voiced plosives was higher and the difference was greater for speakers of Min Dialect. The results of this empirical study theoretically provide some reference for acoustic researches, and pedagogically, provide some implications for optimizations of English curriculums in university.

Voice Onset Time in Children With and Without Vocal Fold Nodules.

Voice onset time (VOT) of voiceless consonants provides information on the coordination of the vocal and articulatory systems. This study examined whether vocal-articulatory coordination is affected by the presence of vocal fold nodules (VFNs) in children. The voices of children with VFNs (6-12 years) and age- and gender-matched vocally healthy controls were examined. VOT was calculated as the time between the voiceless stop consonant burst and the vocal onset of the vowel. Measures of the average VOT and VOT variability, defined as the coefficient of variation, were calculated. The acoustic measure of dysphonia, cepstral peak prominence (CPP), was also calculated. CPP provides information about the overall periodicity of the signal, with more dysphonic voices having lower CPP values. There were no significant differences in either average VOT or VOT variability between the VFN and control groups. VOT variability and average VOT were both significantly predicted by the interaction between Group and CPP. There was a significant negative correlation between CPP and VOT variability in the VFN group, but no significant relationship was found in the control group. Unlike previous studies with adults, there were no group differences in average VOT or VOT variability in this study. However, children with VFNs who were more dysphonic had increased VOT variability, suggestive of a relationship between dysphonia severity and control of vocal onset during speech production.

Laryngeal contrasts in Hadza occlusives

Laryngeal contrasts in consonants are found in nearly all languages. Two-way laryngeal contrasts are common in western European languages, and three- and four-way systems are attested, for example, in many South Asian languages. The current study presents acoustic data on laryngeal contrasts in Hadza, a language isolate spoken by ∼1200 people (Brian Wood, pc.) in Tanzania. Hadza contains multiple complex consonant types, including clicks and ejectives, as well as aspiration and prenasalization. Some previous descriptions suggested a three-way contrast in stops (e.g., /t tʰ d/) and affricates (e.g., t⌢s t⌢sʰ d⌢z), and also a two-way contrast in clicks (e.g., /! !ʰ/) (Tucker et al., 1977; de Voogt, 1992), but did not offer corroborating phonetic evidence. Sands et al. (1996) documented the expected distinction in Voice Onset Time (VOT) between voiceless unaspirated and aspirated stops, but they did not find VOT differences for clicks or affricates. Using wordlist data collected in 2022, this study presents temporal measurements, including VOT, to examine the phonetic properties of laryngeal contrasts in Hadza occlusives and, especially, to evince an aspiration contrast in affricates and clicks previously unsubstantiated in the literature. These results resolve discrepancies between past research and further elucidate the laryngeal system of Hadza.

Evaluation of modified C-palatal plates on speech articulation using acoustic analysis.

The purpose of this study was to assess speech perturbation and adaptation for patients wearing modified C-palatal plates (MCPPs) over time. The sample consisted of 40 patients, 20 wearing MCPPs as the experimental group (age: 20.7± 5.8 years) and 20 patients wearing a transpalatal arch (TPA) as the control group (age: 21.5± 6.4 years). The sounds /t/, /d/, /s/, /n/, /r/, /tʃ/. and /j/ were recorded for each patient at six time points: immediately before (T0) and after (T1) appliance placement; then 1, 2, 3 and 4 weeks after placement (T2-T5). Acoustic analysis of pitch and voice onset time (VOT) was performed by Praat software. Repeated measures analysis of variance (RM-ANOVA) was used to assess changes in the pitch and VOT over time and the difference between the appliances. With the MCPP appliance, /n/, /r/, /tʃ/ and /j/ decreased in VOT starting in the first week while /t/ and /s/ almost returned to pre-treatment levels after 2 weeks. VOT for the /d/ sound did not change between T0 and T3, but it decreased after 3 weeks. There were no significant differences in pitch and VOT between the two groups at any time point. Wearing an MCPP device caused patients to initially distort the articulation of several sounds, but the distortion dissipated within 1 to 2 weeks. It is recommended that patients and/or their parents be advised during pre-treatment counselling of the possibility of temporary speech changes with MCPP placement.

Ink-lithographic fabrication of silver-nanocrystal-based multiaxial strain gauge sensors through the coffee-ring effect for voice recognition applications

Human voice recognition techniques have remarkable potential for clinical applications because information from acoustic signals can reflect human body conditions. This paper reports the fabrication of Ag nanocrystal (NC)-based multiaxial wearable strain gauge sensors by ink-lithography for voice recognition systems. Benefiting from the one-step-device-fabrication strategy of ink-lithography, which can yield Ag NC patterns with specific dimensions and endow physical properties, the Ag NC-based multiaxial strain sensors can be fabricated on an ultrathin substrate (~ 6 μm). Additionally, the coffee-ring effect can be induced onto the Ag NC patterns to realize high sensitivity and angle dependence (gauge factors {G}_{0^circ } = 11.7 ± 1.2 and {G}_{90^circ } = 105.5 ± 20.1); moreover, the voice onset time for voice recognition can be detected by the sensors. These features assist in distinguishing between voiced and voiceless plosive contrasts via measurements of contact-based voice onset time differences and can act as a cornerstone for further advancements in wearable sensors as well as voice recognition and analysis.Graphical

Voice Onset Time in Healthy Young and Old Adults

Objectives: This study aimed to investigate age related changes in articulatory control by examining whether there were differences between young and elderly adults in their voice onset time (VOT). Methods: 16 adults over the age of 65 and 16 adults aged between 18-39 years old participated in this study. The experimental task consisted of 9 plosives, categorized by place of articulation and phonation type, paired with the vowel /a/ to form 2 syllable VCV non-words. Participants’ voice samples were analyzed using Praat. VOT mean was used to examine group differences in VOT and coefficient of variation (CoV) was used to examine group differences in VOT variability. Results: There were significant differences in VOT mean according to age group, phonation type, and place of articulation. The elderly adults had a longer VOT compared to the young adults with significant differences for place of articulation in velar plosives and significant differences for phonation type in aspirated plosives. There were significant differences in VOT CoV according to age group and phonation type. The elderly adults had higher VOT and CoV compared to the young adults with a significant difference in lenis plosives. Conclusion: The results of this study show that elderly adults have longer VOT durations and irregular articulatory control, reflected by higher VOT variability, compared to younger adults. These results may reflect age related declines in the coordination of the speech mechanism and reduced oral motor control.

양측 인공와우이식 아동의 성대진동시작시간 특성

This study aimed to investigate the voice onset time (VOT) of plosives in the VCV syllables by the place of articulation and phonation type spoken by children with bilateral cochlear implants (CIs) in comparison with children with typical hearing (TH). In all, 15 children with bilateral CIs and 15 children with TH participated in this study, aged between 5 to 10 years. All children produced 9 VCV syllables and their VOT were analyzed by the Praat software. There was no significant difference in mean VOT between children with bilateral CIs and children with TH. However, there was a significant difference in mean VOT by the place of articulation, such that the VOT for velars were longer than those for bilabials and alveolars. Additionally, there was a significant difference in mean VOT by the phonation type, such that the VOT of aspirated consonants were longer than those of lenis and fortis consonants. The results of this study suggest that children with bilateral CIs can distinguish the acoustic properties of plosive consonants and control the speech timing between the structures of the larynx and the oral cavity at a similar level as children with TH.

Neural correlates of individual differences in speech categorisation: evidence from subcortical, cortical, and behavioural measures

ABSTRACT Categorisation is a fundamental cognitive ability to group different objects as the same. This ability is particularly indispensable for human speech perception, yet individual differences in speech categorisation are nonetheless ubiquitous. The present study investigates the neurophysiological mechanisms underlying the variability in categorisation of voice-onset time (VOT). Subcortical and cortical speech-evoked responses are recorded to investigate speech representations at two functional levels of auditory processing. Individual differences in psychometric functions correlate positively with how faithfully subcortical responses encode VOT differences. Moreover, individuals also differ in how strongly the subcortical and cortical representations correlate with each other. Listeners with gradient categorisation show higher correspondences between the two representations, indicating that acoustic information is relayed faithfully from the subcortical to the cortical level; listeners with discrete categorisation exhibit decreased similarity between the two representations, suggesting that the subcortical acoustic encoding is transformed at the cortical level to reflect phonetic category information.

Cambios en el voice onset time en hablantes franceses de entre 40 y 80 años de edad

IntroductionThis study explores the ways in which ageing affects speech production. Older individuals present many changes in processes of motor control, as well as in the integrity of laryngeal and supralaryngeal muscles, which may affect speech production. However, few studies have addressed these capacities in the context of healthy ageing, especially in French-speaking people. MethodsThe study focused on voice onset time (VOT), a feature of speech that is particularly relevant in the study of the temporal and spatial coordination of laryngeal and supralaryngeal gestures. We recruited French-speaking individuals, who were grouped according to age, as follows: 40-49, 50-59, 60-69, and 70-79 years. They were asked to perform a pseudoword repetition task including the 6 voiced and voiceless occlusives that exist in the French language: /p, t, k, b, d, g/. ResultsWe observed a longer duration of pseudowords in participants older than 70 years (F[3,847] = 352; p = .02), probably due to slowing of speech movements. In the 70-79 years age group, further difficulties were detected with voice onset and maintenance during occlusion. This resulted in shorter VOT (delayed prevoicing) (F[3,848] = 5.23; p = .001), as well as incomplete voicing (interruption of voicing before opening) of voiced occlusives at the beginning of /b, d, g/ words (F[3,422] = 3.01; p = .03); this, in turn, led to a reduction in the difference in VOT between voiced and voiceless sounds. DiscussionOur results indicate difficulties in the coordination of articulator movements, suggesting an age-related decline in the motor control of speech.

Voice onset time in monolingual and code switching modes in Lebanese Arabic and English

The effect of speaking mode and language in speakers of Lebanese Arabic and English was examined. Voice onset time (VOT) was measured for voiced and voiceless stops in both languages, when speakers were in monolingual mode or code-switching mode. Nine speakers who were highly proficient in English, and used to code-switching, produced 534 tokens in an image-labelling experiment (Olson, 2013; Mayr et al., 2018). Research has found that speakers may produce the same sound differently depending on whether they are in monolingual or bilingual mode (e.g., Olson, 2013; Simonet, 2014; Amengual, 2018). Linear regressions found no significant difference in VOT between conditions (monolingual versus code-switching) or between languages (Arabic versus English). The only significant predictor of VOT was voicing of the stops. Average VOT for voiced and voiceless stops in monolingual Arabic: -59msec &amp; 44msec, monolingual English: -55 ms and 48 ms, code-switched Arabic: -63 ms and 45 ms, and code-switched English: -56 ms and 47 ms. These results indicate voicing during the closure for voiced stops and some aspiration for voiceless stops, and show that speakers do not have separate stop categories for the two languages. Current research is examining monolingual Arabic speakers to determine whether the bilingual speakers have L2 transfer from English aspiration.

Transformation of a temporal speech cue to a spatial neural code in human auditory cortex.

In speech, listeners extract continuously-varying spectrotemporal cues from the acoustic signal to perceive discrete phonetic categories. Spectral cues are spatially encoded in the amplitude of responses in phonetically-tuned neural populations in auditory cortex. It remains unknown whether similar neurophysiological mechanisms encode temporal cues like voice-onset time (VOT), which distinguishes sounds like /b/ and/p/. We used direct brain recordings in humans to investigate the neural encoding of temporal speech cues with a VOT continuum from /ba/ to /pa/. We found that distinct neural populations respond preferentially to VOTs from one phonetic category, and are also sensitive to sub-phonetic VOT differences within a population's preferred category. In a simple neural network model, simulated populations tuned to detect either temporal gaps or coincidences between spectral cues captured encoding patterns observed in real neural data. These results demonstrate that a spatial/amplitude neural code underlies the cortical representation of both spectral and temporal speech cues.

Gender differences in voice onset time perception

It has been known for a while that a gender difference in voice onset time (VOT) production exists such that males typically produce shorter VOTs than females (Swarts, 1992; Robb et al., 2005). However, potential gender differences in VOT perception have not been systematically investigated. This study addresses this question and asks if male and female listeners of English exhibit a different crossover point in a VOT continuum between a voiceless and voiced sound. 11-step VOT continua between /t/ and /d/ (VOT ranges from 70 ms to 5 ms) were created and a set of identification tasks were performed. Results show female listeners switch from a /t/-percept to a /d/-percept at an earlier VOT step (i.e., with a longer VOT) than male listeners do. That is, when female listeners start to categorize a token as a /d/-sound, male listeners still categorize the same token as a /t/-sound. This difference in the perceptual pattern between males and females mirrors their difference in production. VOTs for /t/ are typically shorter for male than female speakers, and male listeners categorize shorter VOT tokens as /t/ more often than female listeners do. This finding highlights the role of social factors like gender in the production-perception link.

Comparison of VOTs in Mandarin–English bilingual children and corresponding monolingual children and adults

Word-initial stops in Mandarin and English show a distinctive phonological categorization but a similar phonetic realization along the VOT (Voice Onset Time) continuum. Previous research reported that native Mandarin adults produce measurably longer long-lag VOTs than native English adults. The present study examined whether and how the difference between Mandarin and English VOTs is manifested in monolingual children and Mandarin–English bilingual children. The participants included 15 five- to six-year-old sequential bilingual children, 24 corresponding monolingual children (15 Mandarin, 9 English), and 22 monolingual adults (12 Mandarin, 10 English). The bilingual children were divided into two groups (Bi-low and Bi-high) based on the amount of experience in English. Each participant was recorded producing 18 Mandarin words and/or 18 English words containing six stops in each language. The VOT values were measured from the beginning of stop burst to the onset of the voicing. The results showed that the language difference in VOT in the monolingual children was manifested in a pattern similar to the monolingual adults. However, Mandarin and English VOTs showed less separable distributions in the two groups of bilingual children. Further analysis suggested that both groups of bilingual children tended to separate Mandarin and English short-lag VOTs but only the Bi-low children showed different long-lag VOTs between the two languages. These results suggested that due to the bilingual effects and L1–L2 (first language – second language) interactions, even though the bilingual children tried to separate the two VOT systems, they implemented the separation in a different manner than the monolingual speakers.

Precision of voicing perceptual identification is altered in association with voice-onset time production changes.

There is ample evidence that motor learning changes the function of perceptual systems. Previous studies examining the interactions between speech production and perception have shown that the discrimination of phonetic contrasts characterized by the difference in articulatory place features is altered following their production changes caused by the perturbation of auditory feedback. The present study focused on a voiced-voiceless contrast in stop consonants, which is characterized by a temporal articulatory parameter, voice-onset time (VOT). In the experiment, we manipulated the participants' motor functions concerning VOT using a cross-categorical auditory feedback (CAF) paradigm (Mitsuya et al. in J Acoust Soc Am 135:2986-2994, 2014), in which a pre-recorded syllable sound starting with a voiced stop consonant (/da/) was fed back simultaneously with the participant's utterance of a voiceless stop consonant (/ta/), and vice versa. The VOT difference between /da/ and /ta/ productions was increased by the CAF, which is consistent with the result of Mitsuya's study. In addition, we conducted perceptual identification tasks of /da/-/ta/ continuum stimuli varying in VOT before and after the CAF task, and found that the identification function became sharper after as compared to before the CAF task. A significant positive correlation between such production and perception changes was also found. On the basis of these results, we consider that the change in motor function concerning VOT affected voiced-voiceless perceptual processing. The present study is the first to show the involvement of the speech production system in the perception of phonetic contrasts characterized by articulatory temporal features.

Effects of age and sex on voice onset time: Evidence from Mandarin voiceless stops

Considerable studies have addressed effects of age and sex on voice onset time (VOT) in English. However, few studies have examined these effects on Mandarin stops. This study attempts to examine effects of age and sex on VOT in Mandarin. A total of 85 Mandarin-speaking children, aged 4–18 years old, and 13 adults as reference participated in a production experiment. Productions were elicited by reading target words in carrier phrases. Results showed that children aged 6–7 years old had longer VOTs than older ones for highly aspirated stops, and the same tendency was not observed for unaspirated stops. However, no linear developmental trend was observed for both highly aspirated and unaspirated stops. In addition, females displayed longer VOTs for highly aspirated stops and shorter for unaspirated stops, whereas significant sex differences in VOTs existed from 14 years old to adulthood for highly aspirated stops, and no significant sex differences in VOTs were found for unaspirated stops in each group, indicating that sex differences in VOTs varied with age and aspiration. The findings suggest that physiological changes in and differences between males and females provide account for some, but not all differences in VOTs across age and sex.

Assessing implicit phonological knowledge through accent imitation

This study investigates learners’ implicit knowledge of Voice Onset Time (VOT), a non-distinctive phonetic difference between German and French. Previous studies on VOT in speech produced by English native speakers learning Spanish (Flege & Hammond 1982) and L1 Spanish-speaking learners of English (Mora et al. 2014) suggest that learners modify their native VOT patterns when attempting to imitate a foreign accent. This was taken as evidence for the development of tacit awareness of cross-language VOT difference between L1 and L2 voiceless stops. In order to determine if similar modifications occur in the productions of German speaking learners of French as a foreign language, we assessed learners’ speech through VOT duration measures in word-initial /p,t,k/. Data was collected through a reading-aloud elicitation task. Results provide support for the hypothesis that German native speakers are able to modify VOT duration when mimicking a French accent. Given these findings, we believe that accent imitation tasks could be used in L2 phonology instruction to raise learners’ awareness of non-distinctive phonetic differences.

Constructing two phonological systems: A phonetic analysis of /p/, /t/, /k/ among early Spanish–English bilingual speakers

Aims and objectives/purpose/research questions: Many early Spanish-English bilingual speakers in the USA learn Spanish as their first language at home and English in school. This paper seeks to elucidate whether these speakers develop a separate phonological system for English and, if so, the role of primary and secondary cues in the development of the second language (L2) system. Design/methodology/approach: The phonetic realization of the voiceless stops /p/, /t/, /k/ is analyzed among three groups: early Spanish-English bilinguals; L1 English speakers who are late learners of Spanish; and L1 Spanish speakers who are late learners of English. The participants ( N = 15) engaged in a reading task and a conversation task in each language during a single recording session. Data and analysis: 1578 tokens of /p/, /t/, /k/ were extracted and analyzed using acoustic software. Voice onset time in milliseconds and center of gravity in Hertz were analyzed, and monofactorial and multifactorial analyses were performed to determine the role of linguistic background. Findings/conclusions: Evidence is found of two phonological systems among early bilingual speakers, with varying degrees of assimilation to the phonological systems of the native speakers of each language. Originality: We argue that early bilinguals construct their L2 system of /p/, /t/, /k/ in English based on the primary cue of voice onset time rather than the secondary cue of center of gravity, as they are accustomed to noticing differences in voice onset time in Spanish and because the center of gravity of /p/, /t/, /k/ in English is more variable than voice onset time, and therefore represents a more variable and less predictable cue for early bilinguals as they construct their L2 system. Significance/implications: This paper contributes to the literature on the construction of phonological systems and to research detailing the speech of early Spanish-English bilinguals.

The role of code-switching and language context in bilingual phonetic transfer

The present study examines the effect of two potential catalysts for interlanguage phonetic interaction, code-switching and language mode, on the production of voice onset time (VOT) to better understand the role of (near) simultaneous dual language activation on phonetic production, as well as the nature of phonetic transfer. An oral production paradigm was carried out in which Spanish–English bilinguals produced words with initial voiceless stops as non-switched tokens, code-switched tokens in an otherwise monolingual context, and code-switched tokens in a bilingual context. Results demonstrated a degree of phonetic transfer associated with code-switching, either unidirectional or bi-directional. Specifically, English, with long lag VOT, was more susceptible to phonetic transfer than Spanish (short lag). Contrary to expectations, while the code-switching effect was present in both monolingual and bilingual mode, there was no additional transfer, or additive effect, of bilingual language mode. Differences in the effects of code-switching on English and Spanish are discussed with respect to the inherently different acceptable VOT ranges in the two languages. Furthermore, the lack of difference in VOT between the code-switched tokens in the monolingual and bilingual contexts is taken to suggest limits on phonetic transfer.