Vowel Space Area Research Articles

Spectral Characteristics of Cardinal Vowels as Indicators of the Auditory Speech Feedback Control in Patients with Moderate and Moderately Severe Chronic Postlingual Sensorineural Hearing Loss

Chronic sensorineural hearing loss (SNHL) is characterized by an increase in hearing thresholds at basic speech frequencies, which implies the auditory speech feedback control worsening and, as a result, changes of speech characteristics. A hypothesis was tested that such worsening can manifest itself in an increase of F0, F1, F2 formants of speech vowel sounds in patients with moderate and moderately severe postlingual SNHL. Recordings of elicited speech were performed for young and middle age women (36–59 years): 7 women speakers with moderate SNHL who did not use hearing aids; 5 women speakers with moderately severe SNHL who were hearing aid users but were not using them during the recordings; a control group of 12 normally hearing women speakers. An assessment of F0, F1 and F2 of stressed vowels [a], [i], [u] and calculations of vowels’ centralization indices – vowel space area, vowel formant centralization ratio and the second formant ratio (F2i/F2u), were performed. All the studied spectral indices in groups of patients with postlingual SNHL were similar to those in the control group, no statistically reliable differences were revealed.

The vowel space as sociolinguistic sign

AbstractThis paper examines variation in vowel space area and its use in social meaning making. Among adolescents at a California high school, patterns of difference in vowel space correlate to social practices of exclusion in the partying scene, albeit alongside explicit discourses of high school social life as inclusive and fluid. I treat vowel space as a sociolinguistic sign, that is, a holistic semiotic resource at play in addition to (or in tandem with) individual segments. Though the semiotic potential of a given linguistic sign is no doubt shaped by large‐scale patterns of variation, the particular manifestations of meaning making are best viewed at the community level alongside other day‐to‐day practices. Further, I suggest that linguistic practices of difference and discourses of sameness are not contradictory, but instead a feature of the semiotic landscape. I thus interpret this vowel space variation as stylistically meaningful within the context of social actors’ ideological orientation to social life.

A comparative study of English vowel shifts and vowel space area among Korean Americans in three dialect regions

AbstractRecent sociophonetic research has focused on the ways in which race and ethnicity influence language as well as how language is used to construct racial and ethnic identity. Comparisons of the speech of members of one ethnic group across different regions are still uncommon. In this study, fifty-one native American English speakers of Korean descent, hailing from three different dialect areas of the United States (Los Angeles County and Orange County, California; Harris County, Texas; and Gwinnett County, Georgia), were recorded speaking English in casual interviews. Their speech was analyzed for characteristics of local sound patterns in each region, including the Short Front Vowel Shift (California Vowel Shift) and the Southern Vowel Shift, as well as overall Vowel Space Area. All three groups showed evidence of the Short Front Vowel Shift, and none demonstrated the Southern Vowel Shift. The Californian speakers had the smallest vowel spaces, while the Georgian speakers had the largest. We relate these findings to the ways Korean Americans in Texas and California understand their ethnic identity vis-à-vis a kind of metropolitan or urban speech style in a highly multicultural environment, while, in comparison, Korean Americans in Georgia may use vowel space to highlight their orientation toward or away from local mainstream (white) cultural identity.

Reduction of vowel space in Alzheimer's disease.

Reduced vowel space area (VSA) is a known effect of neurodegenerative diseases such as Parkinson's disease (PD). Using large publicly available corpuses, two experiments were conducted comparing the vowel space of speakers with and without Alzheimer's disease (AD) during spontaneous and read speech. First, a comparison of vowel distance found reduced distance in AD for English spontaneous speech, but not Spanish read speech. Findings were then verified using an unsupervised learning approach to quantify VSA through cluster center detection. These results corroborate observations for PD that VSA reduction is task-dependent, but further experiments are necessary to quantify the effect of language.

Vowel Acoustics as Predictors of Speech Intelligibility in Dysarthria.

This study sought to determine if alternative vowel space area (VSA) measures (i.e., novel trajectory-based measures: vowel space hull area and vowel space density) predicted speech intelligibility to the same extent as two traditional vowel measures (i.e., token-based measures: VSA and corner dispersion) in speakers with dysarthria. Additionally, this study examined if the strength of the relationship between acoustic vowel measures and intelligibility differed based on how intelligibility was measured (i.e., orthographic transcriptions [OTs] and visual analog scale [VAS] ratings). The Grandfather Passage was read aloud by 40 speakers with dysarthria of varying etiologies, including Parkinson's disease (n = 10), amyotrophic lateral sclerosis (n = 10), Huntington's disease (n = 10), and cerebellar ataxia (n = 10). Token- and trajectory-based acoustic vowel measures were calculated from the passage. Naïve listeners (N = 140) were recruited via crowdsourcing to provide OTs and VAS intelligibility ratings. Hierarchical linear regression models were created to model OTs and VAS intelligibility ratings using the acoustic vowel measures as predictors. Traditional VSA was the sole significant predictor of speech intelligibility for both the OTs (R 2 = .259) and VAS (R 2 = .236) models. In contrast, the trajectory-based measures were not significant predictors of intelligibility. Additionally, the OTs and VAS intelligibility ratings conveyed similar information. The findings suggest that traditional token-based vowel measures better predict intelligibility than trajectory-based measures. Additionally, the findings suggest that VAS methods are comparable to OT methods for estimating speech intelligibility for research purposes.

An Investigation into the Vowel Space Area and Vowel Intelligibility among English-speaking Children with Cochlear Implant in India

Abstract Background: Literature does show that studies of the vowel space area (VSA) can be helpful to know speech production skills in children with hearing impairment (HI) cochlear implant (CI). The need for the present study was to investigate speech production skills among children with CI, who receive Aural Rehab in nonnative language, i.e., English. The VSA offers an easy quick way to compare speech production accuracy among them to typically developing chidlren (TDC) peer group. Aim of the Study: The study aimed at investigating the VSA in F2 versus F1 space formed by vowels /a/, /i/, and /u/ in two groups of children (typically developing [TD] and children with CIs) and the intelligibility of the vowels spoken in the consonant-vowel-consonant (CVC) contexts. Methods: Two groups of subjects participated in the study, 100 children with CIs and 200 age-matched typically developing children. Recordings of vowels /a/, /i/, and /u/ in CVC were used for formant frequency extraction using Praat software, and the VSA was calculated. The recorded utterances were presented to three judges, for the estimation of the percentage of correct responses for identifying the vowel. The VSA for the vowels and the intelligibility scoring in percentage were valuated. Results: The results showed that the VSA among children with CI was significantly less compared to TDC. The reduced VSA represents limited articulatory movement in children with CI compared to children with TD for primary vowels embedded in CVC syllables. The vowel intelligibility for the three vowels in the CVC context was reduced for children with CI (70%) compared to that of children with TDC (95%). Discussion: Both first- and second-formant frequencies show distinct differences between both groups and consequently in the VSA. F1 is lower for /a/ for the CI group, while it is higher for vowel /i/ and /u/ for the CI group compared to the TDC group, while F2, the values were lower for /i/ but elevated significantly for both /a/ and /u/ compared to children in TDC. The intelligibility of their utterances (CVC) of children with CI was lower than that of TDC. Since the children were age- and gender-matched and were nonnative speakers of English, linguistic influences on measured values were minimum. Reasons for changed formant frequencies have to be explored further in terms of the influence of rehabilitation methods, visibility of articulatory movements required, and formant information coded by speech coding strategies. Correlation studies of the VSA and the speech intelligibility measures may assist in therapy outcomes and improve speech intelligibility in children with HI and modifications to mapping strategies employed. Conclusion: The F1 is lower for /a/ for the CI group, while it is higher for vowel /i/ and /u/ for the CI group compared to the TDC group, while F2, the values were lower for /i/ but elevated significantly for both /a/ and /u/ compared to children in TDC. The vowel triangle area was reduced in the speech of CI group subjects compared to that of the group of TDC.

Effect of telepractice on pediatric cochlear implant users and provider vowel space: A preliminary report

Clear speaking styles are goal-oriented modifications in which talkers adapt acoustic-phonetic characteristics of speech to compensate for communication challenges. Do children with hearing loss and a clinical provider modify speech characteristics during telepractice to adjust for remote communication? The study examined the effect of telepractice (tele-) on vowel production in seven (mean age 4:11 years, SD 1:2 years) children with cochlear implants (CIs) and a provider. The first (F1) and second (F2) formant frequencies of /i/, /ɑ/, and /u/ vowels were measured in child and provider speech during one in-person and one tele-speech-language intervention, order counterbalanced. Child and provider vowel space areas (VSA) were calculated. The results demonstrated an increase in F2 formant frequency for /i/ vowel in child and provider speech and an increase in F1 formant frequency for /ɑ/ vowel in the provider speech during tele- compared to in-person intervention. An expansion of VSA was found in child and provider speech in tele- compared to in-person intervention. In children, the earlier age of CI activation was associated with larger VSA in both tele- and in-person intervention. The results suggest that the children and the provider adjust vowel articulation in response to remote communication during telepractice.

Acoustic Predictors of Ease of Understanding in Spanish Speakers With Dysarthria Associated With Parkinson's Disease.

The purpose of this study was to examine selected baseline acoustic features of hypokinetic dysarthria in Spanish speakers with Parkinson's disease (PD) and identify potential acoustic predictors of ease of understanding in Spanish. Seventeen Spanish-speaking individuals with mild-to-moderate hypokinetic dysarthria secondary to PD and eight healthy controls were recorded reading a translation of the Rainbow Passage. Acoustic measures of vowel space area, as indicated by the formant centralization ratio (FCR), envelope modulation spectra (EMS), and articulation rate were derived from the speech samples. Additionally, 15 healthy adults rated ease of understanding of the recordings on a visual analogue scale. A multiple linear regression model was implemented to investigate the predictive value of the selected acoustic parameters on ease of understanding. Listeners' ease of understanding was significantly lower for speakers with dysarthria than for healthy controls. The FCR, EMS from the first 10 s of the reading passage, and the difference in EMS between the end and the beginning sections of the passage differed significantly between the two groups of speakers. Findings indicated that 67.7% of the variability in ease of understanding was explained by the predictive model, suggesting a moderately strong relationship between the acoustic and perceptual domains. Measures of envelope modulation spectra were found to be highly significant model predictors of ease of understanding of Spanish-speaking individuals with hypokinetic dysarthria associated with PD. Articulation rate was also found to be important (albeit to a lesser degree) in the predictive model. The formant centralization ratio should be further examined with a larger sample size and more severe dysarthria to determine its efficacy in predicting ease of understanding.

Correlates of vowel clarity in the spectrotemporal modulation domain: Application to speech impairment evaluation.

This article reports on vowel clarity metrics based on spectrotemporal modulations of speech signals. Motivated by previous findings on the relevance of modulation-based metrics for speech intelligibility assessment and pathology classification, the current study used factor analysis to identify regions within a bi-dimensional modulation space, the magnitude power spectrum, as in Elliott and Theunissen [(2009). PLoS Comput. Biol. 5(3), e1000302] by relating them to a set of conventional acoustic metrics of vowel space area and vowel distinctiveness. Two indices based on the energy ratio between high and low modulation rates across temporal and spectral dimensions of the modulation space emerged from the analyses. These indices served as input for measurements of central tendency and classification analyses that aimed to identify vowel-related speech impairments in French native speakers with head and neck cancer (HNC) and Parkinson dysarthria (PD). Following the analysis, vowel-related speech impairment was identified in HNC speakers, but not in PD. These results were consistent with findings based on subjective evaluations of speech intelligibility. The findings reported are consistent with previous studies indicating that impaired speech is associated with attenuation in energy in higher spectrotemporal modulation bands.

Articulatory undershoot of vowels in isolated REM sleep behavior disorder and early Parkinson’s disease

Imprecise vowels represent a common deficit associated with hypokinetic dysarthria resulting from a reduced articulatory range of motion in Parkinson’s disease (PD). It is not yet unknown whether the vowel articulation impairment is already evident in the prodromal stages of synucleinopathy. We aimed to assess whether vowel articulation abnormalities are present in isolated rapid eye movement sleep behaviour disorder (iRBD) and early-stage PD. A total of 180 male participants, including 60 iRBD, 60 de-novo PD and 60 age-matched healthy controls performed reading of a standardized passage. The first and second formant frequencies of the corner vowels /a/, /i/, and /u/ extracted from predefined words, were utilized to construct articulatory-acoustic measures of Vowel Space Area (VSA) and Vowel Articulation Index (VAI). Compared to controls, VSA was smaller in both iRBD (p = 0.01) and PD (p = 0.001) while VAI was lower only in PD (p = 0.002). iRBD subgroup with abnormal olfactory function had smaller VSA compared to iRBD subgroup with preserved olfactory function (p = 0.02). In PD patients, the extent of bradykinesia and rigidity correlated with VSA (r = −0.33, p = 0.01), while no correlation between axial gait symptoms or tremor and vowel articulation was detected. Vowel articulation impairment represents an early prodromal symptom in the disease process of synucleinopathy. Acoustic assessment of vowel articulation may provide a surrogate marker of synucleinopathy in scenarios where a single robust feature to monitor the dysarthria progression is needed.

Destruction of Vowel Space Area in Patients with Dysphagia after Stroke.

Dysphagia is associated with dysarthria in stroke patients. Vowel space decreases in stroke patients with dysarthria; destruction of the vowel space is often observed. We determined the correlation of destruction of acoustic vowel space with dysphagia in stroke patients. Seventy-four individuals with dysphagia and dysarthria who had experienced stroke were enrolled. For /a/, /ae/, /i/, and /u/ vowels, we determined formant parameter (it reflects vocal tract resonance frequency as a two-dimensional coordinate point), formant centralization ratio (FCR), and quadrilateral vowel space area (VSA). Swallowing function was assessed using the videofluoroscopic dysphagia scale (VDS) during videofluoroscopic swallowing studies. Pearson’s correlation and linear regression were used to determine the correlation between VSA, FCR, and VDS. Subgroups were created based on VSA; vowel space destruction groups were compared using ANOVA and Scheffe’s test. VSA and FCR were negatively and positively correlated with VDS, respectively. Groups were separated based on mean and standard deviation of VSA. One-way ANOVA revealed significant differences in VDS, FCR, and age between the VSA groups and no significant differences in VDS between mild and moderate VSA reduction and vowel space destruction groups. VSA and FCR values correlated with swallowing function. Vowel space destruction has characteristics similar to VSA reduction at a moderate-to-severe degree and has utility as an indicator of dysphagia severity.

Acoustic Characteristics of Cantonese Speech Through Protective Facial Coverings

ObjectivesProtective facial coverings (PFCs) such as surgical masks attenuate speech transmission and affect speech intelligibility, which is reported in languages such as English and German. The present study intended to verify the detrimental impacts on production of tonal languages such as Cantonese, by examining realization of speech correlates in Cantonese under PFCs including facial masks and shields. MethodsWe recorded scripted speech in Hong Kong Cantonese produced by three adult speakers who wore various PFCs, including surgical masks, KF94 masks, and face shields (with and without surgical masks). Spectral and temporal parameters were measured, including mean intensity, speaking rate, long-term amplitude spectrum, formant frequencies of vowels, and duration and fundamental frequency (F0) of tone-bearing parts. ResultsSignificant changes were observed in all acoustic correlates of Cantonese speech under PFCs. Sound pressure levels were attenuated more intensely at ranges of higher frequencies in speech through face masks, whereas sound transmission was affected more at ranges of lower frequencies in speech under face shields. Vowel spaces derived from formant frequencies shrank under all PFCs, with the vowel /aa/ demonstrating largest changes in the first two formants. All tone-bearing parts were shortened and showed increments of F0 means in speech through PFCs. The decrease of tone duration was statistically significant in High-level and Low-level tones, while the increment of F0 means was significant in High-level tone only. ConclusionsGeneral filtering effect of PFCs is observed in Cantonese speech data, confirming language-universal patterns in acoustic attenuation by PFCs. The various coverings lower overall intensity levels of speech and degrade speech signal in higher frequency regions. Modification patterns specific to Hong Kong Cantonese are also identified. Vowel space area is reduced and found associated with increased speaking rates. Tones are produced with higher F0s under PFCs, which may be attributed to vocal tension caused by tightened vocal tract during speaking through facial coverings.

Medium-shifting and intraspeaker variation in conversational interviews

AbstractWe investigate the impact of medium of communication (in-person versus video) on intraspeaker variation in conversation—a process we refer to asmedium-shifting. To quantify the effects of medium-shifting and understand its possible motivations, we analyze three variables that show intraspeaker effects of “clear” or “careful” speech: articulation rate, density-controlled vowel space area, and (ING). The data come from matched in-person and video-mediated interviews with thirty-three repeat guests fromThe Late Show with Stephen Colbert, recorded before and during the COVID-19 pandemic. Mixed-effects regression models show that compared to in-person interviews, video-mediated interviews involve a significantly lower articulation rate and larger vowel space, but no significant difference in (ING). The results suggest that speakers may engage in medium-shifting in order to enhance their intelligibility over video, for example, through more precise articulatory movements and greater contrast between phonemic vowel categories. The null effect of medium on (ING) further suggests that medium-shifting is a motivator of intraspeaker differences even within a single contextual style. An emergent extralinguistic factor affecting speaking behavior and choices, medium-shifting should be carefully considered especially when designing variationist research involving mixed media interviews.

Parents tune their vowels to the emergence of children's words.

The aim of this study was to investigate the acoustic vowel space area in infant directed speech (IDS). The research question is whether the vowel space is expanded or remains constant in IDS. A corpus of spontaneous interactions of 9 dyads followed monthly from the age of 6 to 24 months was analyzed. The occurrences in the parents' speech of each word that the children eventually acquired were extracted. The surface of the vowel triangle and the convex hull of all vowels were computed. The main result is that the development of the vowel space in IDS follows an inverted U-shaped curve: the vowel space starts relatively small, gradually increases as the child's first word use approaches, and decreases again afterwards. These findings show that parents adapt their articulation to the evolving linguistic abilities of their child, and this adaptation can be detected at the level of individual lexical items.

The Effects of Intensive Voice Treatment in Mandarin Speakers With Parkinson's Disease: Acoustic and Perceptual Findings.

This study investigated the effects of intensive voice treatment on subjective and objective measures of speech production in Mandarin speakers with hypokinetic dysarthria. Nine Mandarin speakers with hypokinetic dysarthria due to Parkinson's disease received 4 weeks of intensive voice treatment (4 × 60 min per week). The speakers were recorded reading a passage before treatment (PRE), immediately after treatment (POST), and at 6-month follow-up (FU). Listeners (n = 15) rated relative ease of understanding (EOU) of paired speech samples on a visual analogue scale. Acoustic analyses were performed. Changes in EOU, vocal intensity, global and local fundamental frequency (f o) variation, speech rate, and acoustic vowel space area (VSA) were examined. Increases were found in EOU and vocal intensity from PRE to POST and from PRE to FU, with no change found from POST to FU. Speech rate increased from PRE to POST, with limited evidence of an increase from PRE to FU and no change from POST to FU. No changes in global or local f o variation or in VSA were found. Intensive voice treatment shows promise for improving speech production in Mandarin speakers with hypokinetic dysarthria. Vocal intensity, speech rate, and, crucially, intelligibility, may improve for up to 6 months posttreatment. In contrast, f o variation and VSA may not increase following the treatment. https://doi.org/10.23641/asha.19529017.

Acoustic analysis of vowel production in children with childhood apraxia of speech

Childhood apraxia of speech (CAS) is a complex neurological subtype of speech sound disorder (SSD), involving impaired speech motor planning and programming. Speech characteristics of CAS include difficulty in sequencing speech movements in the absence of muscle weakness resulting in segmental (e.g., vowel/consonant distortions) and suprasegmental (e.g., inappropriate lexical stress) speech deficits. Acoustic analysis offers a robust objective diagnostic measurement of CAS for lexical stress and consonant accuracy/consistency. However, other reported CAS features, such as vowel errors and distortions, have yet to be extensively validated using acoustic analyses. This study will acoustically analyze vowel errors and inconsistencies for corner vowels (/i, u, æ, ɑ/) in children with CAS (aged 8;0 to 15;11) compared to peers with SSD and typical development (TD). Vowel space measures (e.g., vowel space area and formant centralization ratio) and consistency (e.g., vowel cluster distribution) will be assessed in 24 children (CAS = 4, SSD = 10, and TD = 10) across various phonetic contexts (e.g., syllable sequencing between anterior to posterior voiced/voiceless stops of increasing syllable length). It is predicted that children with CAS will demonstrate (1) greater vowel inconsistencies as context complexity increases and (2) a neutralized vowel space based on the corner vowels relative to children with SSD and TD.

Bay Area Spanish: regional sound change in contact languages

Compression of the vowel space area and reduced vowel dispersion have been observed as features of the California Vowel Shift (CVS, D’Onofrio, Pratt, and Van Hofwegen 2019). The present research provides empirical data to address the gap in the literature regarding the influence of regional sound change on contact languages, namely the influence of CVS on Bay Area Spanish. Analysis of word list tasks given to bilingual speakers of Bay Area Spanish and monolingual speakers of Mexican Spanish reveals a more compressed vowel space in Bay Area Spanish and patterns that mirror changes in progress in California English. These results suggest that regional sound changes can influence production within contact languages and may provide evidence for perceptual category assimilation among Spanish-English bilinguals in the Bay Area. These results additionally broaden the scope of regional sound change studies by removing the historically Anglo-centric focus and expanding the consideration of what may constitute a regional feature.

Sex, acoustic space and vowel centralization in Bogota Spanish

The present study analyses sex-specific differences in acoustic vowel space area (VSA), formant centralization ratio (FCR) and vowel dispersion in Bogota Spanish. In addition, we explore the relationship between speaking fundamental frequency (f0), an acoustic parameter that conveys speaker sex information, and VSA.
 Results suggest that, in line with previous research, females have a larger VSA than males. However, some speakers produce vowels that show the opposite pattern to the gender stereotype. Formant centralization and vowel dispersion are related to individual phonetic differences and vowel type respectively. Finally, results show that speakers with a higher average f0 also have larger vowel spaces.

Resonance Characteristics in Epiglottic Cyst: Formant Frequency, Vowel Space Area, Vowel Articulatory Index, and Formant Centralization Ratio

ObjectivesResonance characteristics can change due to alterations in the shape of the vocal tract in patients with epiglottic cysts. This study aimed to analyze the resonance characteristics before and after the surgical excision of epiglottic cysts. MethodsTwelve male patients with epiglottic cysts were enrolled in this study. We analyzed the first and second formants (F1 and F2) in vowels /a/, /e/, /i/, /o/, and /u/, vowel space area (VSA), vowel articulatory index (VAI), and formant centralization ratio (FCR). We measured these parameters before and after the surgical excision of epiglottic cysts. ResultsThere was a significant increase in the F1 values of /a/, VSA, and VAI, and a significant decrease in the value of FCR after the surgery. ConclusionWe confirmed the change in the resonance characteristics in patients with epiglottic cysts. It is considered that further studies on epiglottic cysts and resonance changes are needed in the future.

Telepractice effects: Vowel space characteristics in deaf and hard-of-hearing pediatric patient, provider and caregiver speech

When talkers are aware of speech perception difficulty on the part of the listener due to adverse conditions, they will adopt a “clear speech” style that provides the listener with more salient acoustic cues to access and comprehend the message. Does the use of telepractice affect the vowel articulation in deaf and hard-of-hearing (DHH) pediatric patients, providers and caregivers? This study examined the phonetic modification of the vowel space area in speech of DHH children with cochlear implants (CI) (n = 7, mean age 4 years 11 months), their caregivers and a speech-language pathologist (SLP) during one 30-min in-person and one sequential tele-session, order counterbalanced. The first and second formants of vowels /i/, /a/ and /u/ in child, provider and caregiver productions were measured and vowel space area was calculated. The preliminary analysis including four child-mother dyads demonstrated a significantly larger vowel space area in speech of DHH children and the SLP in the tele- compared to the in-person session. No significant difference in the caregiver vowel space area was identified. The results suggest that DHH children and the clinical provider adjust their vowel articulation in order to accommodate the listener during tele- compared to in-person speech-language intervention.