Vowel Formant Research Articles

Study of vowel formant data using Gabmap: A pilot analysis of a Lithuanian dialect

Abstract The article reviews the possibilities of applying the web application Gabmap developed by researchers at the University of Groningen to the analysis of vowel formant data based on the results of the study of one Lithuanian dialect. The Western Aukštaitian dialect of Kaunas is traditionally considered the basis of Standard Lithuanian. The study was based on the data of 18 male speakers from six dialectal localities representing distinctive areas. The normalized mean values of the first two vowel formants (F1, F2) were analyzed in certain word positions illustrating distinguishing features, which were processed using Gabmap tools designed for analyzing numeric sequences. Gabmap tools most beneficial for the researchers of experimental phonetics along with the aspects of their application to research were emphasized in the study; it also underlined those tools the use of which requires additional application of other conventional methods of experimental sound analysis, such as sound spectrum analysis, planimetric models, etc. In the study of the Western Aukštaitian of Kaunas, the Gabmap analysis confirmed significant horizontal variation within the dialect area and foregrounded the most tightly related sites sharing the greatest number of common features in their vocalism.

Divided Attention Has Limited Effects on Speech Sensorimotor Control.

When vowel formants are externally perturbed, speakers change their production to oppose that perturbation both during the ongoing production (compensation) and in future productions (adaptation). To date, attempts to explain the large variability across individuals in these responses have focused on trait-based characteristics such as auditory acuity, but evidence from other motor domains suggests that attention may modulate the motor response to sensory perturbations. Here, we test the extent to which divided attention impacts sensorimotor control for supralaryngeal articulation. Neurobiologically healthy speakers were exposed to random (Experiment 1) or consistent (Experiment 2) real-time auditory perturbation of vowel formants to measure online compensation and trial-to-trial adaptation, respectively. In both experiments, participants completed two conditions: one with a simultaneous visual distractor task to divide attention and one without this secondary task. Divided visual attention slightly reduced online compensation, but only starting > 300 ms after vowel onset, well beyond the typical duration of vowels in speech. Divided attention had no effect on adaptation. The results from both experiments suggest that the use of sensory feedback in typical speech motor control is a largely automatic process unaffected by divided visual attention, suggesting that the source of cross-speaker variability in response to formant perturbations likely lies within the speech production system rather than in higher-level cognitive processes. Methodologically, these results suggest that compensation for formant perturbations should be measured prior to 300 ms after vowel onset to avoid any potential impact of attention or other higher-order cognitive factors.

Positional Variations of Ukrainian Back Vowel Formants

The purpose of this paper is to study variations in the location of formants of Ukrainian back vowels caused by different phonetic features. To do so, the oscillograms and two-dimensional spectrograms of recorded sounds in speech flow were analyzed. The corresponding invariant acoustic parameters being the ratios between frequencies of the formants rising due to the tube resonance are determined. It is shown that different phonetic environments cause different formant configurations in vowels which is a case of sound assimilation. The following phonetic features were found to give rise to variations of Ukrainian back vowels: coda, distant assimilation by the next or preceding vowel, and progressive assimilation by the preceding hard or palatalized consonant. In particular, high vowels make the other vowels in the phonetic word move higher, and the front ones make the back ones move forward. Such formant shifts are more pronounced in unstressed positions and especially in a coda.

Listen-and-repeat training of non-native vowel quality

This study investigated how listen-and-repeat training affects the production of non-native (Swedish) vowels /y/ and /u/ by speakers of different Namibian languages. Seventeen speakers, who did not have /y/ or /u/ categories in their L1, participated in the experiment. Training effects were measured with acoustic analysis and an identification task performed by 40 proficient Swedish speakers, to see whether the acoustic quality and the perceptual salience of the speakers’ non-native production evolved during training. We expected the speakers’ production to change as a function of training, and the change to be reflected on the vowel formant values and the identification task. The results showed that the speakers produced /u/ close to the trained target already in the first session, but changed their production away from the target after the first training. The speakers’ production of /y/ did not change significantly. The speakers did not reach a perceivable spectral difference between the two non-native vowels. The participants’ productions remained inconsistent throughout the experiment. There was great inter-speaker variation, which could not be accounted for by the speakers’ language backgrounds.

The liminal (vowel) space of womanhood: Fundamental frequency, formants, and the intersex body in Brazil

Abstract Despite the significance of intersex constituencies for explaining the social nature of sex and gender, intersex linguistic and social practices remain a yet unexplored frontier within sociolinguistics. This article examines fundamental frequency (F0) and vowel formant (F1–F3) production by participants with Turner Syndrome (TS), one of the most common intersex chromosomal conditions, in Rio de Janeiro, Brazil. This analysis demonstrates significant differences in fundamental frequency and F3 among different participant groups. I argue that height, growth hormone, and chromosomes are fundamental in constructing womanhood for TS women. Along with relevant ethnographic data, these results call for a re-examination of the body within linguistic and anthropological understandings of ‘womanhood’ and ‘femaleness’. This article highlights the ways these biological factors intersect with gendered perceptions of age and maturity, which can have real-world effects on linguistic practice and the social life of intersex individuals. (Brazilian Portuguese, fundamental frequency, gender, intersex, Turner Syndrome, vowel formants, critical intersex studies)*

Perceptual formant discrimination during speech movement planning.

Evoked potential studies have shown that speech planning modulates auditory cortical responses. The phenomenon's functional relevance is unknown. We tested whether, during this time window of cortical auditory modulation, there is an effect on speakers' perceptual sensitivity for vowel formant discrimination. Participants made same/different judgments for pairs of stimuli consisting of a pre-recorded, self-produced vowel and a formant-shifted version of the same production. Stimuli were presented prior to a "go" signal for speaking, prior to passive listening, and during silent reading. The formant discrimination stimulus /uh/ was tested with a congruent productions list (words with /uh/) and an incongruent productions list (words without /uh/). Logistic curves were fitted to participants' responses, and the just-noticeable difference (JND) served as a measure of discrimination sensitivity. We found a statistically significant effect of condition (worst discrimination before speaking) without congruency effect. Post-hoc pairwise comparisons revealed that JND was significantly greater before speaking than during silent reading. Thus, formant discrimination sensitivity was reduced during speech planning regardless of the congruence between discrimination stimulus and predicted acoustic consequences of the planned speech movements. This finding may inform ongoing efforts to determine the functional relevance of the previously reported modulation of auditory processing during speech planning.

Acoustic Characteristics of Greek Vowels Produced by Adult Heritage Speakers of Albanian

Investigating heritage language (HL)-contact effects on the dominant language has received limited attention despite its importance in understanding the dynamic interplay between linguistic systems in situations of bilingualism. This study compares the acoustic characteristics of Greek vowels produced by heritage speakers (HSs) of Albanian and monolingual Greek speakers, aiming to identify potential differences and explain them. The participants were adult second-generation HSs of Albanian with Greek as their dominant language, born and raised in Greece. A control group of age-matched monolingual Greek speakers was included for comparison purposes. All participants engaged in a controlled speech production task, with the data segmented to extract acoustic values pertaining to the first three formants and the duration of Greek vowels. Bayesian regression models were employed for the subsequent statistical analysis. The results demonstrated differences in the first three formants of certain vowels and the duration of all vowels. These differences can be attributed to the crosslinguistic effect of HL on the dominant language, as well as the interplay between the dynamic and internalized language system of the speakers and the complex effect of the sociophonetic context. These outcomes contribute to the hypothesis positing the emergence of deflected phonetic categories among a distinctive group of bilinguals, namely HSs. Furthermore, this study underscores the significance of a comprehensive exploration of the sociophonetic context of HSs for a nuanced understanding of their phonetic patterns.

Modeling vowel-inherent spectral change in varying consonant context

A wide variety of experimental evidence has shown that vowel inherent spectral change (VISC) is important in vowel identification. This evidence is drawn from production data, statistical pattern recognition, and perceptual experiments with both synthetic or manipulated naturally produced speech. Experimental studies often consider vowels in a constant consonant context which makes it difficult to factor out context effects from the VISC itself. In order to examine the magnitude of these consonant effects, we developed a statistical procedure inspired by Broad and Clermont [(2014). J. Phon. 47, 47–80] in which vowel formant frequencies are approximated by a linear combination of vowel and consonant influences which vary as a function of time. Vowels extracted from a database of both spontaneous and read speech were analyzed to produce context-normalized vowel-formant tracks. Results show that vowel formant frequencies vary systematically across their duration in both spontaneous and read speech and that all consonants in both onset and coda position show significant effects on vowel production across their entire duration. Although these formant patterns are seemingly complex, perceptual evidence suggests that listeners may only attend to onsets and offsets and that deviations from a straight-line interpolation between onset and offset must be relatively large for listeners to discriminate them.

Vowel space expansion following alcohol intoxication

Alcohol intoxication is characterized by hypermetric movements (overshoot) in manual fine motor skills [Phillips et al., (2009). Hum. Movement Sci,. 28(5), 619–632]. It remains unknown whether hypermetric movements manifest in speech following alcohol intoxication. Recent work on a small population (n = 15) revealed vowel space area (VSA) expansion following intoxication [Chang et al., 2023. Proc. ICPhS ‘23 ]. To validate these findings, we made use of the publicly available Alcohol Language Corpus [Schiel et al., 2012. Lang. res. and eval. 46, 503–521]. VSAs were compared across 162 speakers (85 male, 77 female) while sober (n = 162) and intoxicated (blood alcohol level > 0.08%, n = 97) using an unsupervised method based on cluster center detection of normalized vowel formants [Sandoval et al. JASA. 134(5), EL477-EL483]. Substantial VSA expansion was observed for males (10.8%), while a smaller expansion was observed for females (3.6%). These results support recent observations of VSA expansion and suggest hypermetric tongue movement following alcohol intoxication. Further evaluations are ongoing and employ hierarchical linear modeling to compare the effects of specific blood-alcohol concentrations and speech tasks (free speech, tongue-twisters, repetition) on VSA expansion. [Research funded by Tenvos Incorporated for the development of commercial speaker state-detection algorithms.]

Quantifying vowel category distinctness using Bayesian modelling

Phonetic and sociolinguistic studies of vowel merger require a measure of acoustic distinctness between vowel categories. Three desiderata for such a metric are that it be multivariate, in the sense that it account for correlations between dimensions (e.g., F1 and F2), control for other factors affecting vowel formants (e.g. surrounding consonants), and work for unbalanced data (common in naturalistic data). Previous work (Nycz and Hall-Lew, 2013; Kelley & Tucker, 2020) has considered a variety of measures, including variants of Euclidean distance, Pillai score, and Bhattacharyya affinity, but none meet all three criteria. We present a new method for quantifying vowel merger that meets all desiderata and can be applied to different metrics: we fit a Bayesian mixed-effects linear model to jointly predict F1 and F2, then compute any desired metric—here, Euclidean distance, Pillai score, and Bhattacharyya affinity—from the posterior. We evaluate each metric, and the overall method, to describe PIN-PEN across a range of English dialect corpora. We find that controlling for covariates and unbalanced data adds substantial signal, but that multivariate modelling does not perform substantially better than univariate modelling. Additionally, we argue that Bhattacharyya affinity has particularly desirable properties (e.g., allowing for heteroskedastic data: Johnson, 2015).

Acoustics and ice hockey: The sociophonetic impact of Canadian English on American-Born players

My research utilizes sociophonetic analysis to document the linguistic identity construction process that is ongoing in the sport of ice hockey. I argue that American-born players are constructing a hockey-based identity influenced by Canadian English (CE) due to the historical Canadian dominance of the sport. This identity incorporates Canadian Raising, FACE and GOAT monophthongization, both commonly attributed to CE and largely unexplainable based on players’ regional dialects, and altered vowel production in hockey-specific terminology, most notably in the word hockey itself, unique to the hockey community. To document this variation, I analyze vowel formant values taken from sociolinguistic interviews with professional hockey players. I assess F1 and F2 values throughout vowel durations to establish if players are converging in production away from regional dialectal variants towards shared hockey-based variants. I argue these variants have gained indexical value linked to an emerging hockey-based identity that, although influenced by CE, is unique to the hockey community. In ongoing research, I aim to further document that this variation is most evident in hockey-specific terminology and that lexical diffusion occurs outwardly from these terms over time leading to players developing a more prevalent hockey-based identity as the sport gains more importance in their lives.

Modeling the neural encoding of vowel formants in the midbrain

The first (F1) and second (F2) formants of a vowel determine its identity, making it essential to understand how these formant regions are encoded in the brain. We investigated the neural encoding of vowel formants using computational model responses of the auditory nerve and midbrain to natural vowel tokens [Hillenbrand et al., JASA 97, 3099 (1995)]. The first formant peak can be difficult to identify based on model population responses. Responses in the F1 region are more affected by the surrounding harmonic structure, whereas F2 often has a more straightforward representation in the model response. This result is surprising given the sensitivity of listeners for F1 discrimination compared to F2, reflecting Vowel Dispersion Theory [Liljencrants & Lindblom, Language 48, 839 (1972)], which favors the F1 dimension over F2. While peaks are difficult to identify, complex patterns of neural discharge rates observed across low-frequency midbrain responses may work to encode F1. These results suggest revisiting assumptions of the neural representations of formants and highlight the need for a system that evaluates overall response trends to formant regions instead of searching for formant peaks. Neural models can play an important role in understanding the structure of vowel systems. [Work supported by NIDCD-R01-010813.]

Acoustic change complex findings in mild and moderate sensorineural hearing loss

BackgroundAuditory electrophysiological tests of the cortex, which are processed in or close to the auditory cortex, are brain reactions to sound. A variation in a continuous stimulus causes the acoustic change complex potential (ACC), which is a wave following the P1-N1-P2 response.ObjectiveTo measure the amplitude and latency of different components of ACC in normal subjects and across individuals with mild and moderate degrees of sensorineural hearing loss (SNHL).Patients and methodsThe study includes 100 individuals with the age ranged from 10 to 50 years with different degrees of SNHL. The ACC was evoked by a change of second formant in the middle of ongoing steady-state synthetic, 3 formant vowels (ooee). The total duration was 500 ms. Changing occurred at 250 ms.ResultsThe SNHL subgroups showed statistically significantly longer P1 and N1 latencies. N1 and P2 amplitudes of ACC onset response were larger with a statistical significance as compared to controls. Post hoc analysis revealed no statistically significant difference between mild and moderate SNHL on ACC parameters. Age showed a significant negative correlation with ACC N1 and P2 latency, ACC P1 and N1 amplitude, and onset P2 latency. Onset response P1 latency was significantly higher in children than adults. Median ACC P1 amplitude significantly increased in children than adults.ConclusionACC is a reliable tool for testing the auditory cortex function of detecting difference in sounds presented that can be recorded readily in patients with mild and moderate SNHL.

Assessing accuracy of resonances obtained with reassigned spectrograms from the "ground truth" of physical vocal tract models.

The reassigned spectrogram (RS) has emerged as the most accurate way to infer vocal tract resonances from the acoustic signal [Shadle, Nam, and Whalen (2016). "Comparing measurement errors for formants in synthetic and natural vowels," J. Acoust. Soc. Am. 139(2), 713-727]. To date, validating its accuracy has depended on formant synthesis for ground truth values of these resonances. Synthesis is easily controlled, but it has many intrinsic assumptions that do not necessarily accurately realize the acoustics in the way that physical resonances would. Here, we show that physical models of the vocal tract with derivable resonance values allow a separate approach to the ground truth, with a different range of limitations. Our three-dimensional printed vocal tract models were excited by white noise, allowing an accurate determination of the resonance frequencies. Then, sources with a range of fundamental frequencies were implemented, allowing a direct assessment of whether RS avoided the systematic bias towards the nearest strong harmonic to which other analysis techniques are prone. RS was indeed accurate at fundamental frequencies up to 300 Hz; above that, accuracy was somewhat reduced. Future directions include testing mechanical models with the dimensions of children's vocal tracts and making RS more broadly useful by automating the detection of resonances.

Acoustic and Perceptual Effects of Articulation Exercises in Transgender Women.

This study measured the impact of articulation exercises using a cork and articulation exercises for lip spreading on the formant frequencies of vowels and listener perceptions of femininity in transgender women. Thirteen transgender women were recorded before and after the cork exercise and before and after the lip spreading exercise. Speech samples included continuous speech during reading and were analyzed using Praat software. Vowel formant frequencies (F1, F2, F3, F4, F5) and vowel space were determined. A listening experiment was organized using naïve cisgender women and cisgender men rating audio samples of continuous speech. Masculinity/femininity, vocal quality and age were rated, using a visual analogue scale (VAS). Concerning vowel formant frequencies, F2 /a/ and F5 /u/ significantly increased after the lip spreading exercise, as well as F3 /a/, F3 /u/ and F4 /a/ after the cork exercise. The lip spreading exercise had more impact on the F2 /a/ than the cork exercise. Vowel space did not change after the exercises. The fundamental frequency (fo) increased simultaneously during both exercises. Both articulation exercises were associated with significantly increased listener perceptions of femininity of the voice. Subtle changes in formant frequencies can be observed after performing articulation exercises, but not in every formant frequency or vowel. Cisgender listeners rated the speech of the transgender women more feminine after the exercises. Further research with a more extensive therapy program and listening experiment is needed to examine these preliminary findings.

VoxSenes Acoutic Database

Motivated by the need to increase knowledge about the effect of age on speech production, and by the lack of speech data on European Portuguese (EP), this work focuses on the development of a speech database, with acoustic data of healthy adults using standardized recording procedures. The objective of this database is to support a comprehensive analysis of age and gender effects in EP speech at segmental and suprasegmental levels. In this vein, the present work provides the description of one acoustic speech database containing all EP vowels produced in similar context (reading speech), and also semi-spontaneous speech (image description) collected from a large sample of 144 adults from the central region of Portugal, between the ages 35 and 97. This paper summarizes the research design of the acoustic database and includes details about the study region, participants, participants’ tasks, corpus, data acquisition, and segmentation/annotation of the data. This database has been used in different studies, where various aspects of the aging speech were explored through different methods, such as static acoustic features and dynamic vowel formants. However, the collected data could be used on other acoustic studies of speech over the lifespan.

Effects of the landline telephone filter and linguistic context on speaker-dependent variability in /s/

Previous research has demonstrated that vowel formants situated near the lower limit of the bandwidth show effects of the telephone filter (Künzel 2001; Byrne and Foulkes 2004). In this work, the effects of the landline telephone filter are examined for one consonant, namely fricative /s/. Although this speech sound is expected to show large effects of narrowband telephone filters due to its high-frequency spectral characteristics, previous work on Dutch telephone speech showed that, despite its compromised acoustics, /s/ still contains considerable amounts of speaker information (Smorenburg & Heeren, 2021). Using English data that were simultaneously recorded as broadband and telephone speech, this work shows large effects of the telephone filter on both the acoustics and linear discriminant analysis (LDA) speaker classification. Linguistic effects were only observable in studio recordings and generally did not have an effect on the speaker classification with one exception: when the following context is labial, LDA speaker-classification accuracy was higher, indicating idiosyncrasies in anticipatory labial coarticulation.

Using Formant Characteristics of Russian Vowels and Consonants for User Authentication

The article proposes a method for user authentication based on formant characteristics. A biometric image has been developed consisting of the formant characteristics of 46 sounds of the Russian language (6 vowels, 4 diphthongs and 36 consonants). An authentication system architecture based on formant characteristics and frequency of the leading formant of vowels and consonants is proposed. A Module for extracting the formant characteristics of vowels and consonants has been developed. A block diagram of the Module for extracting the formant characteristics of vowels and consonants and block diagrams of its submodules are presented. The Random Forest algorithm, k-nearest neighbors, logistic regression, multilayer perceptron and Support Vector Machine are combined into a cluster of algorithms. A block diagram of training and testing models based on a cluster of algorithms is given. Models were trained on the basis of algorithms clusters. The results of the experiment were obtained and their analysis was carried out.

Different hemispheric lateralization for periodicity and formant structure of vowels in the auditory cortex and its changes between childhood and adulthood

The spectral formant structure and periodicity pitch are the major features that determine the identity of vowels and the characteristics of the speaker. However, very little is known about how the processing of these features in the auditory cortex changes during development. To address this question, we independently manipulated the periodicity and formant structure of vowels while measuring auditory cortex responses using magnetoencephalography (MEG) in children aged 7–12 years and adults. We analyzed the sustained negative shift of source current associated with these vowel properties, which was present in the auditory cortex in both age groups despite differences in the transient components of the auditory response. In adults, the sustained activation associated with formant structure was lateralized to the left hemisphere early in the auditory processing stream requiring neither attention nor semantic mapping. This lateralization was not yet established in children, in whom the right hemisphere contribution to formant processing was strong and decreased during or after puberty. In contrast to the formant structure, periodicity was associated with a greater response in the right hemisphere in both children and adults. These findings suggest that left-lateralization for the automatic processing of vowel formant structure emerges relatively late in ontogenesis and pose a serious challenge to current theories of hemispheric specialization for speech processing.

Developmental Trajectory of the Frequency-Following Response During the First 6 Months of Life.

The aim of the present study is to characterize the maturational changes during the first 6 months of life in the neural encoding of two speech sound features relevant for early language acquisition: the stimulus fundamental frequency (fo), related to stimulus pitch, and the vowel formant composition, particularly F1. The frequency-following response (FFR) was used as a snapshot into the neural encoding of these two stimulus attributes. FFRs to a consonant-vowel stimulus /da/ were retrieved from electroencephalographic recordings in a sample of 80 healthy infants (45 at birth and 35 at the age of 1 month). Thirty-two infants (16 recorded at birth and 16 recorded at 1 month) returned for a second recording at 6 months of age. Stimulus fo and F1 encoding showed improvements from birth to 6 months of age. Most remarkably, a significant improvement in the F1 neural encoding was observed during the first month of life. Our results highlight the rapid and sustained maturation of the basic neural machinery necessary for the phoneme discrimination ability during the first 6 months of age.