Carrier Phrase Research Articles

Acoustics of the tense-lax stop contrast in Semarang Javanese

Javanese has a contrast between tense and lax stops. While both tense and lax stops are voiceless and unaspirated, the contrast at least in word-initial position is realized through acoustic differences in the following vowel, including lower f0, breathier voice quality, and higher F1 for the lax stops relative to their tense counterparts. However, previous reports have indicated substantial cross-speaker variation, and in some cases involve differing characterizations of the acoustic contrast, possibly due to small sample sizes. Moreover, it is still unclear whether (and how) this contrast is maintained in word-final position. In this study, we investigate the tense-lax contrast based on audio recordings of 27 speakers of Central Javanese from Semarang, Indonesia who each read 30 or more items with a word-initial or word-final stop in a carrier phrase. Stops and their adjacent vowels were hand-annotated, and measurements were taken including voice onset and offset time, stop closure and release duration, f0, formant frequencies, and spectral tilt and noise levels. Discussion will focus on how the tense-lax contrast is realized in both word-initial and word-final positions, as well as how different acoustic correlates co-vary within and across speakers.

Aerodynamic and Laryngeal Characteristics of Place-Dependent Voice Onset Time Differences

Objective: To investigate aerodynamic and laryngeal factors associated with place-dependent voice onset time (VOT) differences. Methods: The speech materials were /p∧, t∧, k∧/, each produced 15 times by 10 adult English speakers in the carrier phrase “say __ again”. The sound pressure level was targeted within a ±3 dB range. Intraoral air pressure (Po) was obtained using a buccal-sulcus approach. VOT, Po, maximum Po declination rate (MPDR), duration of the laryngeal devoicing gesture (LDG), occlusion duration, and the duration of the Po drop to baseline (atmosphere) to the onset of voicing (PDOV) were determined for each stop. Results: VOT was longer for the alveolar and velar stops compared to the bilabial stop. A constant LDG was observed for all stops regardless of place of articulation. Occlusion duration, however, was significantly shorter for the alveolar and velar stops compared to the bilabial stop. Aerodynamically, Po was greatest for the velar stop, intermediate for the alveolar stop, and smallest for the bilabial stop. MPDR index showed a slower rate of Po drop for the velar and alveolar stops compared with the bilabial stop. PDOV was found to be longer for /p/ than /t/ and /k/. Conclusion: Findings provide empirical evidence for the inter-related roles of Po, rate of Po change, and laryngeal factors in place-dependent variations of VOT.

Fricative Contrast and Coarticulation in Children With and Without Speech Sound Disorders.

The purpose of this study was, first, to expand our understanding of typical speech development regarding segmental contrast and anticipatory coarticulation, and second, to explore the potential diagnostic utility of acoustic measures of fricative contrast and anticipatory coarticulation in children with speech sound disorders (SSD). In a cross-sectional design, 10 adults, 17 typically developing children, and 11 children with SSD repeated carrier phrases with novel words with fricatives (/s/, /ʃ/). Dependent measures were 2 ratios derived from spectral mean, obtained from perceptually accurate tokens. Group analyses compared adults and typically developing children; individual children with SSD were compared to their respective typically developing peers. Typically developing children demonstrated smaller fricative acoustic contrast than adults but similar coarticulatory patterns. Three children with SSD showed smaller fricative acoustic contrast than their typically developing peers, and 2 children showed abnormal coarticulation. The 2 children with abnormal coarticulation both had a clinical diagnosis of childhood apraxia of speech; no clear pattern was evident regarding SSD subtype for smaller fricative contrast. Children have not reached adult-like speech motor control for fricative production by age 10 even when fricatives are perceptually accurate. Present findings also suggest that abnormal coarticulation but not reduced fricative contrast is SSD-subtype-specific. S1: https://doi.org/10.23641/asha.5103070. S2 and S3: https://doi.org/10.23641/asha.5106508.

The phonetics of code-switched vowels

Aims and Objectives: This study investigates the effects of code-switching on vowel quality, pitch and duration among English–French bilinguals. Code-switching has been claimed to influence the morphology, syntax and lexicon, but not the phonology of the switched language. However, studies on voice-onset time have found subtle phonetic effects of code-switching, even though there are no categorical phonological effects. We investigate this further through the following three questions: (1) Are F1 and F2 influenced in the process of code-switching? (2) Are code-switched words hyper-articulated? (3) Does code-switching have an effect on vowel duration before voiced and voiceless consonants? Methodology: To address our research questions we relied on an insertional switching method where words from one language were inserted into carrier phrases of the other to simulate English–French code-switching environments. Bilingual speakers were recorded while they read code-switched sentences as well as sentences that did not involve code-switching, that is, monolingual sentences. Data and Analysis: The vowels of target words in the recorded utterances were compared – code-switched contexts against monolingual contexts – for vocalic duration, F0, F1 and F2. Findings/Conclusions: Like previous voice-onset time studies, our results indicate that code-switching does not shift the phonology to that of the embedded language. We did, however, find subtle lower level phonetic effects, especially in the French target words; we also found evidence of hyper-articulation in code-switched words. At the prosodic level, target switch-words approached the prosodic contours of the carrier phrases they are embedded in. Originality: The approach taken in this study is novel for its investigation of vowel properties instead of voice-onset time. Significance: This new approach to investigating code-switching adds to our understanding of how code-switching affects pronunciation.

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.

Latviešu /v/ un /ʝ/: dažādu realizāciju akustiskais pētījums

Šī pētījuma mērķis ir noskaidrot latviešu valodas fonēmu /v/ un /ʝ/ distribūciju CVC struktūras vārdos. Rakstā analizēti šādi akustiskie parametri: dinamiskās pētāmo skaņu spektrogrammas, relatīvā intensitāte un formantu parēju (patskanis ⇨ līdzskaņi /v/ un /ʝ/) relatīvais ilgums.Balstoties uz paveikto analīzi, secināms, ka līdzskaņa /v/ dominējošais variants gan prevokāliskā, gan postvokāliskā pozīcijā ir frikatīvs spraudzenis, bet līdzskanis /ʝ/ prevokāliskajā pozīcijā visbiežāk tiek izrunāts kā frikatīvs spraudzenis, postvokāliskā pozīcijā – kā nefrikatīvs spraudzenis vai patskanis. Frikatīvajiem spraudzeņiem, salīdzinot ar nefrikatīvajiem spraudzeņiem, ir raksturīgas augstākas spektrālās smailes frekvences vērtības un plašāks vērtību diapazons. Relatīvās intensitātes vērtības samazinās secībā patskanis > nefrikatīvais spraudzenis > frikatīvais spraudzenis, turklāt frikatīvajiem spraudzeņiem ir vislielākā intensitāte. Attiecībā uz patskaņa formantu pārejas relātīvo ilgumu, abus līdzskaņus iespējams raksturot pēc līdzīgas tendences: frikatīvajiem spraudzeņiem ir īsākas blakus esoša patskaņa formantu pārejas nekā nefrikatīvajiem spraudzeņiem un patskaņiem

Voiceless alveolar stop coarticulation in typically developing 5-year-olds and 13-year-olds

ABSTRACTIn this study, vowel-on-consonant lingual coarticulation at [t] closure offset was compared in 5-year-old children and 13-year-old adolescents. The study aimed to establish whether, by the end of the closure, children from the younger age group adjust the tongue shape to the following vowels to the same extent as adolescents. Ten 5-year-olds and ten 13-year-olds, all speakers of Scottish Standard English, produced [t]-vowel syllables with the vowels [i] and [a], in a carrier phrase. Measures of tongue shape based on midsagittal ultrasound imaging data were used to compare anticipatory coarticulation and within-speaker variability across groups. Both age groups changed the extent of tongue dorsum bunching in order to coarticulate the consonant with the following vowels. The 5-year-old children, unlike the adolescents, did not consistently modify the bunching location within the tongue curve to accommodate the tongue shape to that of the upcoming vowel. Token-to-token variability was significantly greater in the younger age group. The results suggest that vowel-on-[t] coarticulatory patterns produced by typically developing children are affected by the development of motor control, with articulatory constraints on the tongue limiting the extent of lingual coarticulation in 5-year-old children. The findings on typical coarticulation development are relevant for clinical practice, and they highlight the need for more detailed descriptions of how phonetic characteristics of speech sounds affect coarticulation throughout childhood.

O contraste entre oclusivas alveolares e velares em dados típicos de fala: análises acústica e ultrassonográfica

This study used acoustic and articulatory analyses to characterize the contrast between alveolar and velar stops with typical speech data, comparing the parameters (acoustic and articulatory) of adults and children with typical speech development. The sample consisted of 20 adults and 15 children with typical speech development. The analyzed corpus was organized through five repetitions of each target-word (/'kap ə/, /'tapə/, /'galo/ e /'daɾə/). These words were inserted into a carrier phrase and the participant was asked to name them spontaneously. Simultaneous audio and video data were recorded (tongue ultrasound images). The data was submitted to acoustic analyses (voice onset time; spectral peak and burst spectral moments; vowel/consonant transition and relative duration measures) and articulatory analyses (proportion of significant axes of the anterior and posterior tongue regions and description of tongue curves). Acoustic and articulatory parameters were effective to indicate the contrast between alveolar and velar stops, mainly in the adult group. Both speech analyses showed statistically significant differences between the two groups. The acoustic and articulatory parameters provided signals to characterize the phonic contrast of speech. One of the main findings in the comparison between adult and child speech was evidence of articulatory refinement/maturation even after the period of segment acquisition.

Categorical perception of lexical tones by English learners of Mandarin Chinese.

Whether native speakers of non-tonal languages can acquire categorical representations of lexical tones remains controversial. This study investigates the acquisition of lexical tone categories by native English speakers learning Mandarin Chinese as a foreign language by comparing the categorical perception (CP) of lexical tones between three groups of listeners: (1) native English speakers who had taken advanced Mandarin courses in colleges; (2) native English speakers with no knowledge of Mandarin Chinese; and (3) native Mandarin speakers. Two tonal continua derived from natural speech within carrier phrases were created through interpolation within two tonal contrasts (tone 1/tone 4, T1/T4; tone 2/tone 3, T2/T3). Results showed categorical-like perception of tones by native Mandarin speakers. The inexperienced English speakers performed near chance on discrimination tasks and showed significantly broader identification boundaries than the other two groups. The learners of Mandarin showed similar pattern of CP to native Mandarin speakers, but with higher overall discrimination scores. Findings suggest that CP of lexical tone may be available to advanced second language learners.

What does sinewave speech tell us about phonetic perception?

It has been 35 years since the striking demonstration that intelligible speech can be created by mixing sinusoids that follow the formants of natural speech [Remez et al. (1981) Science 212, 947-950]. A good deal has been written about what sinewave speech (SWS) might reveal about the mechanisms underlying phonetic perception. However, most of the experimental work on SWS has been carried out using well-formed sentences whose intelligibility depends on many factors other than phonetic identification. Results will be reported for experiments designed to measure SWS intelligibility explicitly at the phonetic level. For example, listeners were asked to identify the vowel in SW /hVd/ syllables. Intelligibility was far above chance (55%) but dramatically lower than that of the original utterances. Further tests showed: (1) intelligibility increased substantially when the SW syllable was preceded by a brief SW carrier phrase (CP); (2) tests that alternated trials with and without the SW CP showed that CP enhancement is a real-time effect; (3) SW vowels can be classified using a template-matching algorithm trained on naturally spoken vowels at rates exceeding those of human listeners. Preliminary results will be reported for consonant recognition using SW nonsense syllables. [Work supported by NIH.]

Importance of F0 for predicting vocal emotion categorization

Affective prosody is used to produce and express specific emotions to conversation partners. While pitch has been identified as a crucial cue for differentiating between emotions, there has been significant variation in the stimuli used by different groups of researchers to examine the acoustic cues necessary for the perception of vocal emotions. The Toronto Emotional Speech Set consists of 2800 items: 200 sentences (carrier phrase “say the word” followed by a target word) spoken by two adult female actors (one younger and one older) to portray seven emotions (anger, disgust, fear, sadness, happiness, pleasant surprise, neutral). In the current study, these stimuli were analyzed to determine which acoustical cues accounted for the most variance in categorizing stimuli into one of the seven pre-determined emotional conditions. The acoustical characteristics of mean duration, mean intensity, mean F0, mean range of intensity, and mean range of F0 were analyzed using a customized Praat script for each of the ...

Implosives in Jakarta Indonesian

Some Jakarta Indonesian speakers produce implosives as allophones of the voiced stops /b/ and /d/. Implosives are typically characterized by increasing voicing amplitude during closure, shorter closure duration and/or creaky phonation of the following vowel, but their actual realization shows much variation across languages (see Ladefoged & Maddieson 1996; Lindau 1984). This study investigates the acoustic properties of Indonesian implosives. Thirty-three native speakers of Jakarta Indonesian were recorded. Each speaker produced one hundred words with initial /b/, /d/ or /p/ in different vowel contexts (e.g. /baik/, /biru/) embedded in carrier phrases. A trained phonetician judged whether each case of /b/ and /d/ in their speech was imploded or not. I measured the voicing amplitude and duration of each target stop and the creakiness of the following vowel by means of harmonic amplitude differences such as H1-H2 (Keating et al. 2010). A preliminary analysis reveals that stops judged as implosives generally had more increasing voicing amplitude than those judged as modal plosives. The former also had a shorter duration and their following vowels had relatively low H1-H2 and H1-A2 values, which indicates creakier phonation. The analysis also shows that implosivization is more likely to occur before a non-high back vowel.

Sensorimotor Oscillations Prior to Speech Onset Reflect Altered Motor Networks in Adults Who Stutter.

Adults who stutter (AWS) have demonstrated atypical coordination of motor and sensory regions during speech production. Yet little is known of the speech-motor network in AWS in the brief time window preceding audible speech onset. The purpose of the current study was to characterize neural oscillations in the speech-motor network during preparation for and execution of overt speech production in AWS using magnetoencephalography (MEG). Twelve AWS and 12 age-matched controls were presented with 220 words, each word embedded in a carrier phrase. Controls were presented with the same word list as their matched AWS participant. Neural oscillatory activity was localized using minimum-variance beamforming during two time periods of interest: speech preparation (prior to speech onset) and speech execution (following speech onset). Compared to controls, AWS showed stronger beta (15–25 Hz) suppression in the speech preparation stage, followed by stronger beta synchronization in the bilateral mouth motor cortex. AWS also recruited the right mouth motor cortex significantly earlier in the speech preparation stage compared to controls. Exaggerated motor preparation is discussed in the context of reduced coordination in the speech-motor network of AWS. It is further proposed that exaggerated beta synchronization may reflect a more strongly inhibited motor system that requires a stronger beta suppression to disengage prior to speech initiation. These novel findings highlight critical differences in the speech-motor network of AWS that occur prior to speech onset and emphasize the need to investigate further the speech-motor assembly in the stuttering population.

Effect of several acoustic cues on perceiving Mandarin retroflex affricates and fricatives in continuous speech.

Relatively little attention has been paid to the perception of the three-way contrast between unaspirated affricates, aspirated affricates and fricatives in Mandarin Chinese. This study reports two experiments that explore the acoustic cues relevant to the contrast between the Mandarin retroflex series /tʂ/, /tʂ(h)/ and /ʂ/ in continuous speech. Twenty participants performed two three-alternative forced-choice tasks, in which acoustic cues including closure, frication duration (FD), aspiration, and vocalic contexts (VCs) were systematically manipulated and presented in a carrier phrase. A subsequent classification tree analysis shows that FD distinguishes /tʂ/ from /tʂ(h)/ and /ʂ/, and that closure cues the affricate manner. Interactions between VC and individual cues are also found. The FD threshold for separating /ʂ/ and /tʂ/ is susceptible to the influence of the following vocalic segments, shifting to lower values if frication is followed by the low vowel /a/. On the other hand, while aspiration cues /tʂ(h)/ before /a/ and //, this acoustic cue is obscured by gesture continuation when /tʂ(h)/ precedes its homorganic approximant /ɻ/ in natural speech, which might cause potential confusion between /tʂ(h)/ and /ʂ/.

Top-Down Modulation on the Perception and Categorization of Identical Pitch Contours in Speech and Music.

Whether pitch in language and music is governed by domain-specific or domain-general cognitive mechanisms is contentiously debated. The aim of the present study was to investigate whether mechanisms governing pitch contour perception operate differently when pitch information is interpreted as either speech or music. By modulating listening mode, this study aspired to demonstrate that pitch contour perception relies on domain-specific cognitive mechanisms, which are regulated by top–down influences from language and music. Three groups of participants (Mandarin speakers, Dutch speaking non-musicians, and Dutch musicians) were exposed to identical pitch contours, and tested on their ability to identify these contours in a language and musical context. Stimuli consisted of disyllabic words spoken in Mandarin, and melodic tonal analogs, embedded in a linguistic and melodic carrier phrase, respectively. Participants classified identical pitch contours as significantly different depending on listening mode. Top–down influences from language appeared to alter the perception of pitch contour in speakers of Mandarin. This was not the case for non-musician speakers of Dutch. Moreover, this effect was lacking in Dutch speaking musicians. The classification patterns of pitch contours in language and music seem to suggest that domain-specific categorization is modulated by top–down influences from language and music.

Extrinsic talker normalization via rapid accumulation of talker-specific phonetic detail

Talker normalization makes speech processing more efficient by reducing the degrees of freedom between the highly variable acoustic realization of speech and its abstract mental representation. However, it is unknown how processing gains afforded by talker normalization depend on the amount of talker-specific information available in the preceding speech context. We explored the timecourse of extrinsic talker normalization in a series of speeded classification tasks that parametrically varied the amount of talker-specific phonetic detail available in the preceding speech context. In single- and mixed-talker conditions, listeners identified a target word (either “boot” or “boat”) preceded by either no speech context, a short carrier phrase (“It's a...”), or a long carrier phrase (“I owe you a...”) spoken by the same talker as the target word. Listeners' word identification was always slower in the mixed-talker condition than the single-talker one. However, the amount of interference decreased as the amount of preceding speech context increased: the interference effect of the mixed-talker condition was greatest with no carrier, less with a short carrier, and least in the long-carrier condition. These results reveal how extrinsic talker normalization facilitates speech processing via rapid accumulation of talker-specific detail from the speech context.

Three-dimensional tongue shapes of /r/ production in American English words

A number of studies have shown that /r/ production in American English involves complex tongue shapes. Previous 3D imaging studies, however, have been limited to sustained (static) /r/ sounds produced in supine position. Since supine versus upright posture and static versus dynamic speech production influences the shape of the tongue, it is unclear to what degree previous findings of three-dimensional tongue shapes are generalizable to /r/ sounds produced dynamically and with upright posture. This study presents upright-posture 3D tongue shapes of dynamically produced /r/ sounds from words embedded in a carrier phrase. Twenty young adult native speakers of American English participated in the study (10 males and 10 females), and analyses are ongoing.

Perception of voice onset time in Singapore English

This study investigates how voice onset time (VOT) is perceived in Singapore English (SgE). SgE research acknowledges that Singaporeans linguistically accommodate their listeners—varying between using Standard Singapore English (SSE) or Singlish (colloquial SgE) depending on addressee. Liu 2011 (n.p.) suggests these linguistic accommodations are reflected in VOT production, finding Singaporeans to produce more short-lag VOT (indicative of Singlish) when speaking to other Singaporeans and longer VOT (indicative of SSE) when speaking to Americans. Though these are sub-categorical shifts, they demonstrate the utility of VOT in speakers’ efforts when accommodating listeners. The current study tests whether VOT is also available as a salient and social perceptual cue. Three listening experiments investigate (1) Singaporeans’ baseline categorical perception of a /ba/-/pa/ continuum, (2) whether this baseline is affected when heard with socially salient pictures (i.e., linguistic stereotypes—an ah lian or a business woman), and (3) whether dialectal carrier phrases—whether stimuli are presented within a SSE or Singlish phrase—affects perception of the same stimuli. Preliminary results show listener age and educational background, which allude to an effect of dialectal experience (Sumner and Samuel 2009), play important roles in the perception of VOT.

Experience with code-switching modulates the use of grammatical gender during sentence processing.

Using code-switching as a tool to illustrate how language experience modulates comprehension, the visual world paradigm was employed to examine the extent to which gender-marked Spanish determiners facilitate upcoming target nouns in a group of Spanish-English bilingual code-switchers. The first experiment tested target Spanish nouns embedded in a carrier phrase (Experiment 1b) and included a control Spanish monolingual group (Experiment 1a). The second set of experiments included critical trials in which participants heard code-switches from Spanish determiners into English nouns (e.g., la house) either in a fixed carrier phrase (Experiment 2a) or in variable and complex sentences (Experiment 2b). Across the experiments, bilinguals revealed an asymmetric gender effect in processing, showing facilitation only for feminine target items. These results reflect the asymmetric use of gender in the production of code-switched speech. The extension of the asymmetric effect into Spanish (Experiment 1b) underscores the permeability between language modes in bilingual code-switchers.

Phonetic basis of phonemic paraphasias in aphasia: Evidence for cascading activation

Phonemic paraphasias are a common presenting symptom in aphasia and are thought to reflect a deficit in which selecting an incorrect phonemic segment results in the clear-cut substitution of one phonemic segment for another. The current study re-examines the basis of these paraphasias. Seven left hemisphere-damaged aphasics with a range of left hemisphere lesions and clinical diagnoses including Broca's, Conduction, and Wernicke's aphasia, were asked to produce syllable-initial voiced and voiceless fricative consonants, [z] and [s], in CV syllables followed by one of five vowels [i e a o u] in isolation and in a carrier phrase. Acoustic analyses were conducted focusing on two acoustic parameters signaling voicing in fricative consonants: duration and amplitude properties of the fricative noise. Results show that for all participants, regardless of clinical diagnosis or lesion site, phonemic paraphasias leave an acoustic trace of the original target in the error production. These findings challenge the view that phonemic paraphasias arise from a mis-selection of phonemic units followed by its correct implementation, as traditionally proposed. Rather, they appear to derive from a common mechanism with speech errors reflecting the co-activation of a target and competitor resulting in speech output that has some phonetic properties of both segments.