Vowel Context Research Articles

The perceptual distinctiveness of the [n-l] contrast in different vowel and tonal contexts.

This study investigates the relative perceptual distinction of the [n] vs [l] contrast in different vowel contexts ([_a] vs [_i]) and tonal contexts (high-initial such as HH, HL, vs low-initial such as LL, LH). The results of two speeded AX discrimination experiments indicated that a [n-l] contrast is perceptually more distinct in the [_a] context and with a high-initial tone. The results are consistent with the typology of the [n] vs [l] contrast across Chinese dialects, which is more frequently observed in the [_a] context and with a high-initial tone, supporting a connection between phonological typology and perceptual distinctiveness.

What R Mandarin Chinese /ɹ/s? - acoustic and articulatory features of Mandarin Chinese rhotics.

Rhotic sounds are well known for their considerable phonetic variation within and across languages and their complexity in speech production. Although rhotics in many languages have been examined and documented, the phonetic features of Mandarin rhotics remain unclear, and debates about the prevocalic rhotic (the syllable-onset rhotic) persist. This paper extends the investigation of rhotic sounds by examining the articulatory and acoustic features of Mandarin Chinese rhotics in prevocalic, syllabic (the rhotacized vowel [ɚ]), and postvocalic (r-suffix) positions. Eighteen speakers from Northern China were recorded using ultrasound imaging. Results showed that Mandarin syllabic and postvocalic rhotics can be articulated with various tongue shapes, including tongue-tip-up retroflex and tongue-tip-down bunched shapes. Different tongue shapes have no significant acoustic differences in the first three formants, demonstrating a many-to-one articulation-acoustics relationship. The prevocalic rhotics in our data were found to be articulated only with bunched tongue shapes, and were sometimes produced with frication noise at the start. In general, rhotics in all syllable positions are characterized by a close F2 and F3, though the prevocalic rhotic has a higher F2 and F3 than the syllabic and postvocalic rhotics. The effects of syllable position and vowel context are also discussed.

Perceptual compensation for vowel intrinsic f0 effects in native English speakers.

High vowels have higher f0 than low vowels, creating a context effect on the interpretation of f0. Since onset F0 is a cue to stop voicing, the vowel context is expected to influence voicing judgements. Listeners categorized syllables starting with high ("bee"-"pea") and low ("bye"-"pie") vowels varying orthogonally in VOT and onset F0. Listeners made use of both cues as expected. Furthermore, vowel height affected listeners' categorization. Syllables with the low vowel /a/ elicited more voiceless responses compared to syllables with the high vowel /i/. This suggests that listeners compensate for vowel intrinsic effects when making other phonemic judgements.

Apparent-time variation in the use of multiple cues for perception of anticipatory nasal coarticulation in California English

This study examines apparent-time variation in the use of multiple acoustic cues present on coarticulatorily nasalized vowels in California English. Eighty-nine listeners ranging in age from 18-58 (grouped into 3 apparent-time categories based on year of birth) performed lexical identifications on syllables excised from words with oral and nasal codas from six speakers who produced either minimal (n=3) or extensive (n=3) anticipatory nasal coarticulation (realized by greater vowel nasalization, F1 bandwidth, and diphthongization on vowels in CVN contexts). Results showed no differences across listeners’ identification for Extensively coarticulated vowels, as well as oral vowels by both types of speakers (all at-ceiling). Yet, performance for the Minimal Coarticulators’ nasalized vowels was lowest for the older listener group and increased over apparent-time. Perceptual cue-weighting analyses revealed that older listeners rely more on F1 bandwidth, while younger listeners rely more on acoustic nasality, as coarticulatory cues providing information about lexical identity. Thus, there is evidence for variation in apparent- time in the use of the different coarticulatory cues present on vowels. Younger listeners’ cue weighting allows them flexibility to identify lexical items given a range of coarticulatory variation across (here, younger) speakers, while older listeners’ cue weighting leads to reduced performance for talkers producing innovative phonetic forms. This study contributes to our understanding of the relationship between multidimensional acoustic features resulting from coarticulation and the perceptual re-weighting of cues that can lead to sound change over time.

Differential spectral characteristics of the Spanish fricative /s/ in the articulation of individuals with dysarthria and apraxia of speech

PurposeThis study examines whether there are differences in the speech of speakers with dysarthria, speakers with apraxia and healthy speakers in spectral acoustic measures during production of the central-peninsular Spanish alveolar sibilant fricative /s/. MethodTo this end, production of the sibilant was analyzed in 20 subjects with dysarthria, 8 with apraxia of speech and 28 healthy speakers. Participants produced 12 sV(C) words. The variables compared across groups were the fricative's spectral amplitude difference (AmpD) and spectral moments in the temporal midpoint of fricative execution. ResultsThe results indicate that individuals with dysarthria can be distinguished from healthy speakers in terms of the spectral characteristics AmpD, standard deviation (SD), center of gravity (CoG) and skewness, the last two in context with unrounded vowel, while no differences in kurtosis were detected. Participants with AoS group differ significantly from healthy speaker group in AmpD, SD and CoG and Kurtosis, the first one followed unrounded vowel and the latter two followed by rounded vowels. In addition, speakers with apraxia of speech group returned significant differences with respect to speakers with dysarthria group in AmpD, CoG and skewness. ConclusionsThe differences found between the groups in the measures studied as a function of the type of vowel context could provide insights into the distinctive manifestations of motor speech disorders, contributing to the differential diagnosis between apraxia and dysarthria in motor control processes.

Bilinguals from Larynx to Lips: Exploring Bilingual Articulatory Strategies with Anatomic MRI Data.

The goal of this article is to illustrate the use of MRI for exploring bi- and multi-lingual articulatory strategies. One male and one female speaker recorded sets of static midsagittal MRIs of the whole vocal tract, producing vowels as well as consonants in various vowel contexts in either the male's two or the female's three languages. Both speakers were native speakers of English (American and Australian English, respectively), and both were fluent L2 speakers of French. In addition, the female speaker was a heritage speaker of Croatian. Articulatory contours extracted from the MRIs were subsequently used at three progressively more compact and abstract levels of analysis. (1) Direct comparison of overlaid contours was used to assess whether phones analogous across L1 and L2 are similar or dissimilar, both overall and in specific vocal tract regions. (2) Consonant contour variability along the vocal tract due to vowel context was determined using dispersion ellipses and used to explore the variable resistance to coarticulation for non-analogous rhotics and analogous laterals in Australian, French, and Croatian. (3) Articulatory modeling was used to focus on specific articulatory gestures (tongue position and shape, lip protrusion, laryngeal height, etc.) and then to explore the articulatory strategies in the speakers' interlanguages for production of the French front rounded vowel series. This revealed that the Australian and American speakers used different strategies to produce the non-analogous French vowel series. We conclude that MRI-based articulatory data constitute a very rich and underused source of information that amply deserves applications to the study of L2 articulation and bilingual and multi-lingual speech.

Comparison the Voice Onset Time (VOT) of Postlingual Cochlear Implant Users and Normal Peers in the CAPE_V Sentences as Continues Speech Task

BackgroundAuditory perception plays a crucial role in speech and language development, emphasizing concerns about hearing loss. While cochlear implantation nearly tackles challenges associated with post-lingual hearing loss in adults, the importance of "auditory feedback" and acoustic assessment becomes crucial for evaluating speech disorders and devising effective treatments. This study aims to address the gap in assessing Voice Onset Time (VOT) as an indicator of nuanced variations in the speech of cochlear implant users during a continuous speech task. MethodRecordings of Persian CAPE-V sentences were obtained from 25 cochlear implant (CI) users and 25 healthy speakers, with a mean age of 33.2 years (SD=11.5, range=18-55 years). Ten words, incorporating both voiced and voiceless consonants, were selected from the CAPE-V sentences. VOT measurements for the specified stop consonants at the initial syllables of these chosen words were computed using PRAAT. A comparative analysis between the two age- and gender-matched groups was conducted using an independent sample t-test. Subsequently, ANCOVA was employed to examine the influence of demographic factors on VOT values among CI participants. ResultsUnvoiced consonant /p/ in /po/, /pɑ/, /pe/, and /pa/ syllables had higher VOT values in the healthy group, while the voiced consonant /d/ in /da/ and /di/ syllables demonstrated higher VOT values in the CI group. (P<0.05) Apart from /po/ and /di/ syllables, no significant impacts of demographic factors on VOT values were observed (P≥0.8). ConclusionDespite the improvement in speech quality after cochlear implantation, subtle differences persist. The motor theory, which underscores the impact of auditory inputs on temporal coordination, highlights the role of VOT in speech discrimination. Various linguistic factors affect VOT, including articulation position, vowel context, and raised vowels. While CI enhances syllable distinction, challenges in articulation for adults suggest a need for targeted training in rehabilitation programs, ultimately enhancing the quality of life for CI users.

Influence of the European Portuguese phonological system on the perception of close-mid and open-mid vowels

This study’s purpose was to analyse the influence of neutralisation on the perception of European Portuguese (EP) close-mid and open-mid vowels, and the gradient between the /i/, /e/, /ε/ and /a/ phonological categories. A fuzzy boundary between mid-vowels has been described in the phonological systems of various languages including EP, a variety of Portuguese with complex phonological phenomena and exceptional realisations of vowels in different contexts. Fifteen listeners from Lisbon participated in two tasks: Identification and goodness rating of 20 random repetitions of 31 stimuli from a /i/-/e/-/ε/-/a/ continuum. The boundaries between categories in the identification task, the internal structures of each category and the gradient of each boundary in the goodness rating task were analysed. Logistic regression was used to analyse the individual responses of listeners and the internal structure of phonemic categories, and prototypes were determined using bubble charts of goodness scores. The gradient of boundaries was analysed using two sets of data: X responses and goodness ratings. Models of the gradients of transition were developed using a mixed effects regression approach. Results from the identification task showed four vowel categories marked by three distinct boundaries. The stimulus with the highest score was approximately in the centroid and the goodness score decreased as the stimulus moved away from the centroid, which constitutes new evidence of an internal structure of the phonemic categories in EP. The main implications of the results obtained are for the description and typology of phonological phenomena in EP, supporting the existence of a non-partial contrast (which does not neutralise in any context) between /ε/ and /a/, and revealing less robust /i/-/e/ and /e/-/ε/ phonemic oppositions.

Formant dynamics in second language speech: Japanese speakers' production of English liquids.

This article reports an acoustic study analysing the time-varying spectral properties of word-initial English liquids produced by 31 first-language (L1) Japanese and 14 L1 English speakers. While it is widely accepted that L1 Japanese speakers have difficulty in producing English /l/ and /ɹ/, the temporal characteristics of L2 English liquids are not well-understood, even in light of previous findings that English liquids show dynamic properties. In this study, the distance between the first and second formants (F2-F1) and the third formant (F3) are analysed dynamically over liquid-vowel intervals in three vowel contexts using generalised additive mixed models (GAMMs). The results demonstrate that L1 Japanese speakers produce word-initial English liquids with stronger vocalic coarticulation than L1 English speakers. L1 Japanese speakers may have difficulty in dissociating F2-F1 between the liquid and the vowel to a varying degree, depending on the vowel context, which could be related to perceptual factors. This article shows that dynamic information uncovers specific challenges that L1 Japanese speakers have in producing L2 English liquids accurately.

An Acoustic Analysis of Voice Onset Time in the Production of Voiceless Plosives in English and Iraqi Tikrity Arabic

This paper is a study of voice onset time (VOT) in Iraqi Tikrity Arabic and English. The stops /t, k/ were used in initial position and were embedded in words which were presented to ten native speakers of Iraqi Tikrity Arabic and four English native speakers. Recordings were made and analyzed using computer software that generated a spectrogram for each word (prrat). The results prove that stops in Iraqi Tikrity Arabic and in English occur at the same place along the VOT. The study also found that place of articulation has a significant effect on VOT values and asserts the strong relationship between VOT values and place of articulation. Moreover vowel context has its significant effect on VOT values and asserts the strong relationship between VOT values and vowel context. Additionally, it is found that gender impact on VOT values varied from one language group to another, gender has no significant effect in the production of voiceless plosives in Iraqi Tikrity Arabic. Whereas English male speakers produce longer voice onset time than Female speakers.

Northern Lisu vowels &amp; tones, and their interactions

Lisu is a Sino-Tibetan language of Central Ngwi branch. It has multiple tonal contrasts and a typologically unusual vowel inventory. In this talk, I present an acoustic phonetic study based on data collected from eleven speakers of Northern Lisu, spoken in Nujiang Autonomous Prefecture in Yunnan, Southwestern China. The study focuses on the vowels and tones of the language, and their interaction. Northern Lisu has six tones, including four modal and two creaky-voiced tones; it has ten vowels, including five front vowels, four back vowels, and a central “fricative” vowel. Tone and vowel interaction is analyzed using Esling’s Laryngeal Articulator Model. Results show all speakers produce a lower f0 in the retracted vowel context, but it is not the case that all tones are creakier in this same vowel context. Simultaneously, male and female speakers show differences in terms of voice quality. Examination of the vowel space shows a reduction in many vowel contrasts. It is suggested that the vowel space is becoming regularised, with perceptually difficult contrasts being neutralised. In addition, it is shown that the fricative vowel contains minimal frication compared to the fricative consonants, and as such is better described as a syllabic retroflex approximant.

An Acoustic Analysis of Voice Onset Time in the Production of Voiceless Plosives in English and Iraqi Kurdish

This paper is a study of voice onset time)VOT( in Iraqi Kurdish and English. The stops /t, k/ were used in initial position and were embedded in words which were presented to ten native speakers of Iraqi Kurdish and four English native speakers. Recordings were made and analyzed using a computer software that generated a spectrogram for each word (prrat). The results prove that stops in Iraqi Kurdish and in English occur at the same place along the VOT. The study also found that Place of articulation has a significant effect on VOT values and asserts the strong relationship between VOT values and place of articulation. Moreover vowel context has its significant effect on VOT values and asserts the strong relationship between VOT values and vowel context. Additionally, it is found that gender impact on VOT values varied from one language group to another, gender has no significant effect in the production of voiceless plosives in Iraqi Kurdish. Whereas English male speakers produce longer voice onset time than Female speakers.

An Acoustic Analysis of Voice Onset Time in the Production of Voiceless Plosives in English and Iraqi Turkmen

This paper is a study of voice onset time, VOT, in Iraqi Turkmen and English. The stops /t, k/ were used in initial position and were embedded in words which were presented to ten native speakers of Iraqi Turkmen and four English native speakers. Recordings were made and analyzed using computer software that generated a spectrogram for each word (prrat). Results prove that stops in Iraqi Turkmen and in English occur at the same place along the VOT. The study also found that Place of articulation has a significant effect on VOT values and asserts the strong relationship between VOT values and place of articulation. Moreover vowel context has its significant effect on VOT values and asserts the strong relationship between VOT values and vowel context. Additionally, it is found that gender impact on VOT values varied from one language group to another, gender has no significant effect in the production of voiceless plosives in Iraqi Turkmen. Whereas English male speakers produce longer voice onset time than Female speakers.

Intelligibility of Word-Initial Obstruent Consonants in Mandarin-Speaking Prelingually Deafened Children With Cochlear Implants.

This study assessed the intelligibility of obstruent consonants in prelingually deafened Mandarin-speaking children with cochlear implants (CIs). Twenty-two Mandarin-speaking children with normal hearing (NH) aged 3.25-10.0 years and 35 Mandarin-speaking children with CIs aged 3.77-15.0 years were recruited to produce a list of Mandarin words composed of 17 word-initial obstruent consonants in different vowel contexts. The children with CIs were assigned to chronological age-matched (CA) and hearing age-matched (HA) subgroups with reference to the NH controls. One hundred naïve NH adult listeners were recruited for a consonant identification task that consisted of a total of 2,663 stimulus tokens through an online research platform. For each child speaker, the consonant productions were judged by seven to 12 different adult listeners. An average percentage of consonants correct was calculated across all listeners for each consonant. The CI children in both the CA and HA subgroups showed lower intelligibility in their consonant productions than the NH controls. Among the 17 obstruents, both CI subgroups showed higher intelligibility for stops, but they demonstrated major problems with the sibilant fricatives and affricates and showed a different confusion pattern from the NH controls on these sibilants. Of the three places (alveolar, alveolopalatal, and retroflex) in Mandarin sibilants, both CI subgroups showed the lowest intelligibility and the greatest difficulties with alveolar sounds. For the NH children, there was a significant positive relationship between overall consonant intelligibility and chronological age. For the children with CIs, the best fit regression model revealed significant effects of chronological age and age at implantation, with their quadratic terms included. Mandarin-speaking children with CIs experience major challenges in the three-way place contrasts of sibilant sounds in consonant production. Chronological age and the combined effect of CI-related time variables play important roles in the development of obstruent consonants in the CI children.

PHONEME RECOGNITION AND CONFUSIONS IN PATIENTS WITH SENSORINEURAL HEARING LOSS

Hearing impaired listeners show different phoneme confusions during speech recognition testing. The aim of the study was to analyze phoneme recognition in patients with sensorineural hearing loss during word recognition testing with monosyllable words, as well as, to compare consonant confusions in different vowel context. Recognition of 18 initial and final consonants was analyzed in a total of 698 presentations of the words. There were 1154 (82.7%) correct recognitions and 100 consonant confusions (7.2%). The patients did not response at a total of 71 presentations of the words which means that consonants in 142 cases (10.2%) were not recognized, nor confused. There are no consonant confusion patterns during suprathreshold testing with real words. In cases of phoneme confusions, listeners replace the stimulus word with another word from the lexical neighborhood. In terms of the vowel context, the consonants are the most easily identified in the context of the vowel /a/.

Smartphone Recordings are Comparable to “Gold Standard” Recordings for Acoustic Measurements of Voice

PurposeThe purpose of this study was to assess the relationship and comparability of cepstral and spectral measures of voice obtained from a high-cost “flat” microphone and precision sound level meter (SLM) vs. high-end and entry level models of commonly and currently used smartphones (iPhone i12 and iSE; Samsung s21 and s9 smartphones). Device comparisons were also conducted in different settings (sound-treated booth vs. typical “quiet” office room) and at different mouth-to-microphone distances (15 and 30 cm). MethodsThe SLM and smartphone devices were used to record a series of speech and vowel samples from a prerecorded diverse set of 24 speakers representing a wide range of sex, age, fundamental frequency (F0), and voice quality types. Recordings were analyzed for the following measures: smoothed cepstral peak prominence (CPP in dB); the low vs high spectral ratio (L/H Ratio in dB); and the Cepstral Spectral Index of Dysphonia (CSID). ResultsA strong device effect was observed for L/H Ratio (dB) in both vowel and sentence contexts and for CSID in the sentence context. In contrast, device had a weak effect on CPP (dB), regardless of context. Recording distance was observed to have a small-to-moderate effect on measures of CPP and CSID but had a negligible effect on L/H Ratio. With the exception of L/H Ratio in the vowel context, setting was observed to have a strong effect on all three measures. While these aforementioned effects resulted in significant differences between measures obtained with SLM vs. smartphone devices, the intercorrelations of the measurements were extremely strong (r's > 0.90), indicating that all devices were able to capture the range of voice characteristics represented in the voice sample corpus. Regression modeling showed that acoustic measurements obtained from smartphone recordings could be successfully converted to comparable measurements obtained by a "gold standard" (precision SLM recordings conducted in a sound-treated booth at 15 cm) with small degrees of error. ConclusionsThese findings indicate that a variety of commonly available modern smartphones can be used to collect high quality voice recordings usable for informative acoustic analysis. While device, setting, and distance can have significant effects on acoustic measurements, these effects are predictable and can be accounted for using regression modeling.

Articulation differences of /s/ observed using inverse tongue atlas modeling

Depending on the vowel context, the consonant /s/ can be articulated by engaging different functional units of the tongue. An inverse finite element (FE) tongue model comprising hexahedral elements generated from a 4D statistical MRI atlas of 22 speakers performing the speech tasks “a geese” (tongue moving forwards) and “a souk” (tongue moving backwards) is used to study this articulatory behavior. The model uses a state-of-the-art inverse tracking controller to simulate the motion of internal tissue points of the different speakers deformed into the atlas space. Motion tracking is successfully carried out by minimizing the L2-norm of velocity error of FEM nodes using the Cottle–Dantzig algorithm. The results show that for “a-geese,” the utterance of /s/ in context of vowel /i/ showed increase in activation of tongue protruder muscles such as genioglossus posterior, floor muscle geniohyoid by ∼5% more than in the case of “a-souk.” In “a-souk” relative activity increased in the tongue retractor muscles mid- and anterior-genioglossus, and superior longitudinal by ∼4%. Our findings are consistent with subject-specific state-of-the-art models and with articulatory expectations. The inverse atlas tongue model can be further used to estimate such articulation behavior on extended datasets of subjects performing more variations of speech tasks.

Development of a normative baseline for speech stability in lingual articulation

In typical speech production, speakers usually use the same articulatory gesture for a particular speech sound in a particular context (such as a /k/ sound after an /i/ vowel). However, since people are not machines, there is inherent variation in how precisely a speech gesture is repeated. Previous research on consistency of tongue articulation has found individual variation in articulatory consistency in tongue posture that may also provide insight into communication disorders, such as stuttering (Frisch et al., 2016, Clinical Linguistics and Phonetics). This presentation will report on pilot data for the development a normative measure for speech stability to establish how much variation is typical for different age groups and whether the complexity of speech materials influences the articulatory measure of speech stability. Included in the pilot methodology are (1) a wide variety of lingual consonants, (2) variation in vowel context, and (3) evaluation of a perceptual proxy measure for speech stability that could be practically used in a clinical environment.

Contrast enhancement in clearly spoken Mandarin sibilants

Clearly spoken sibilants have been shown to exhibit temporal, spectral, and amplitudinal enhancement, though most existing work focuses on English. This study presents acoustics of clearly spoken sibilants in Mandarin, which exhibits a three-way place contrast between alveolar, retroflex, and alveopalatal sibilant fricatives. Sibilant-initial stimuli were elicited in a carrier phrase and were crossed according to: sibilant (alveolar, retroflex, alveopalatal), vowel context (a u), word frequency, number of syllables, and tone. The participants were eight native speakers of Mandarin with origins in mainland China. The first block was a baseline with no instruction on speech style. In the second block they were instructed to speak clearly 'as if talking to someone hard of hearing'. In the third block they were instructed to speak conversationally 'as if casually talking to a friend'. As expected, speakers enhanced duration and amplitude in the clear speech block and reduced duration and amplitude in the conversational block. Departing from previous work, spectral moments were not significantly enhanced in clear speech, which could be due to differences in type of task. However, second formants of vowels following alveopalatal sibilants were significantly higher in the clear speech block. This would be expected if clear speech is generally contrast enhancing, as the second formant of the following vowel is known to be the primary cue distinguishing the alveopalatal in perception and production.

Effect of Speaker Age on Listener Perceptions of Word-Final /l/.

This study investigated an effect of speaker age on listeners' perception of word-final /l/ produced by child and adult speakers of Southern White Vernacular English, a dialect that shows higher rates of word-final /l/ vocalization than other dialects of English. Stimuli included children and adults' word-final /l/ embedded in monosyllabic words in two vowel contexts (/i, ɪ/ and /ɔ, ɑ/). A total of 25 monolingual adult listeners listened to each word and were asked to judge the /l/-likeness using a visual analog scale. Average listener ratings and three acoustic measures (F2 transition rate [F2 TR] and F2-F1 [Hz] values at 20% and 80% time points along the vowel-/l/ duration) were analyzed. Adult productions were rated more as correct /l/ than those of children in both vowel contexts, despite the similarity in their F2 TR and F2-F1 values at the 80% time point. Correlation between the acoustic measures and the average listener ratings were weak for all three measures for adults' productions. For children's productions, while the correlation with F2 TR values were weak, moderate significant correlations were found for F2-F1 values at the 20% and 80% time points. In terms of vowel context, word-final /l/ in the high front vowel context was rated more as /l/ than those in low back vowel context. Findings suggest that listeners are more likely to accept word-final /l/ as being correct when produced by adult speakers, regardless of their acoustic characteristics, but more likely to perceive an error when produced by a child and attend more to acoustic information for their perceptual judgment. This highlights the importance of considering children's dialectal background when judging word-final /l/, which is more likely to be vocalized in certain dialects and certain vowel contexts, and thus can be misjudged without such consideration.