Associations Between Speaking Fundamental Frequency, Vowel Formant Frequencies, and Listener Perceptions of Speaker Gender and Vocal Femininity–Masculinity

Purpose The aim of the study was to examine associations between speaking fundamental frequency ( f os ), vowel formant frequencies ( F ), listener perceptions of speaker gender, and vocal femininity–masculinity. Method An exploratory study was undertaken to examine associations between f os , F 1 – F 3 , listener perceptions of speaker gender (nominal scale), and vocal femininity–masculinity (visual analog scale). For 379 speakers of Australian English aged 18–60 years, f os mode and F 1 – F 3 (12 monophthongs; total of 36 F s) were analyzed on a standard reading passage. Seventeen listeners rated speaker gender and vocal femininity–masculinity on randomized audio recordings of these speakers. Results Model building using principal component analysis suggested the 36 F s could be succinctly reduced to seven principal components (PCs). Generalized structural equation modeling (with the seven PCs of F and f os as predictors) suggested that only F 2 and f os predicted listener perceptions of speaker gender (male, female, unable to decide). However, listener perceptions of vocal femininity–masculinity behaved differently and were predicted by F 1 , F 3 , and the contrast between monophthongs at the extremities of the F 1 acoustic vowel space, in addition to F 2 and f os . Furthermore, listeners' perceptions of speaker gender also influenced ratings of vocal femininity–masculinity substantially. Conclusion Adjusted odds ratios highlighted the substantially larger contribution of F to listener perceptions of speaker gender and vocal femininity–masculinity relative to f os than has previously been reported.

The Effects of Language Contact on Non-Native Vowel Sequences in Lexical Borrowings: The Case of Media Lengua

Media Lengua (ML), a mixed language derived from Quichua and Spanish, exhibits a phonological system that largely conforms to that of Quichua acoustically. Yet, it incorporates a large number of vowel sequences from Spanish which do not occur in the Quichua system. This includes the use of mid-vowels, which are phonetically realized in ML as largely overlapping with the high-vowels in acoustic space. We analyze and compare production of vowel sequences by speakers of ML, Quichua, and Spanish through the use of generalized additive mixed models to determine statistically significant differences between vowel formant trajectories. Our results indicate that Spanish-derived ML vowel sequences frequently differ significantly from their Spanish counterparts, largely occupying a more central region of the vowel space and frequently exhibiting markedly reduced trajectories over time. In contrast, we find only one case where an ML vowel sequence differs significantly from its Quichua counterpart—and even in this case the difference from Spanish is substantially greater. Our findings show how the vowel system of ML successfully integrates novel vowel sequence patterns from Spanish into what is essentially Quichua phonology by markedly adapting their production, while still maintaining contrasts which are not expressed in Quichua.

Perceptual validation of vowel normalization methods for variationist research

The evaluation of normalization methods sometimes focuses on the maximization of vowel-space similarity. This focus can lead to the adoption of methods that erase legitimate phonetic variation from our data, that is, overnormalization. First, a production corpus is presented that highlights three types of variation in formant patterns: uniform scaling, nonuniform scaling, and centralization. Then the results of two perceptual experiments are presented, both suggesting that listeners tend to ignore variation according to uniform scaling, while associating nonuniform scaling and centralization with phonetic differences. Overall, results suggest that normalization methods that remove variation not according to uniform scaling can remove legitimate phonetic variation from vowel formant data. As a result, although these methods can provide more similar vowel spaces, they do so by erasing phonetic variation from vowel data that may be socially and linguistically meaningful, including a potential male-female difference in the low vowels in our corpus.

Intact Correction for Self-Produced Vowel Formant Variability in Individuals With Cerebellar Ataxia Regardless of Auditory Feedback Availability

Purpose Individuals with cerebellar ataxia (CA) caused by cerebellar degeneration exhibit larger reactive compensatory responses to unexpected auditory feedback perturbations than neurobiologically typical speakers, suggesting they may rely more on feedback control during speech. We test this hypothesis by examining variability in unaltered speech. Previous studies of typical speakers have demonstrated a reduction in formant variability (centering) observed during the initial phase of vowel production from vowel onset to vowel midpoint. Centering is hypothesized to reflect feedback-based corrections for self-produced variability and thus may provide a behavioral assay of feedback control in unperturbed speech in the same manner as the compensatory response does for feedback perturbations. Method To comprehensively compare centering in individuals with CA and controls, we examine centering in two vowels (/i/ and /ɛ/) under two contexts (isolated words and connected speech). As a control, we examine speech produced both with and without noise to mask auditory feedback. Results Individuals with CA do not show increased centering compared to age-matched controls, regardless of vowel, context, or masking. Contrary to previous results in neurobiologically typical speakers, centering was not affected by the presence of masking noise in either group. Conclusions The similar magnitude of centering seen with and without masking noise questions whether centering is driven by auditory feedback. However, if centering is at least partially driven by auditory/somatosensory feedback, these results indicate that the larger compensatory response to altered auditory feedback observed in individuals with CA may not reflect typical motor control processes during normal, unaltered speech production.

Acoustic differentiation of allophones of /aɪ/ in Chicagoland English: Statistical comparison of formant trajectories

Diphthongs have a dynamic formant structure. Nevertheless, many quantitative studies of diphthongs are based on measurements at only two points, somewhere in the nucleus and somewhere in the glide. The question arises as to whether analyses based on values at only two points provide an adequate understanding of the dynamics of diphthongs. Wieling (2018) mentions the analysis of /aɪ/ raising in Chicago English in Hualde, Luchkina & Eager (2017) as one of several examples of recent studies where potentially interesting patterns may have been missed because of limited sampling of formant values, and proposes using Generalized Additive Mixed Models (GAMM) to allow a more complete understanding of diphthong dynamics. In this paper, we examine the acoustic nature of the (quasi-)phonemic differentiation between two originally allophonic variants of the diphthong /aɪ/ in the US English of Chicago and the surrounding area. We offer an acoustic analysis based on full formant trajectories of diphthongs with data obtained from a group of 53 speakers. The results of a GAMM analysis are then compared with those obtained in Hualde et al. (2017), which considered values at only two points and from a smaller set of speakers (17). We also discuss the main advantages of GAMM analysis over other techniques that have being proposed for the analysis of differences in vowel formant dynamics.

Musical Hearing and Musical Experience in Second Language English Vowel Acquisition

Purpose Former studies suggested that music perception can help produce certain accentual features in the first and second language (L2), such as intonational contours. What was missing in many of these studies was the identification of the exact relationship between specific music perception skills and the production of different accentual features in a foreign language. Our aim was to verify whether empirically tested musical hearing skills can be related to the acquisition of English vowels by learners of English as an L2 before and after a formal accent training course. Method Fifty adult Polish speakers of L2 English were tested before and after a two-semester accent training in order to observe the effect of musical hearing on the acquisition of English vowels. Their L2 English vowel formant contours produced in consonant–vowel–consonant context were compared with the target General British vowels produced by their pronunciation teachers. We juxtaposed these results with their musical hearing test scores and self-reported musical experience to observe a possible relationship between successful L2 vowel acquisition and musical aptitude. Results Preexisting rhythmic memory was reported as a significant predictor before training, while musical experience was reported as a significant factor in the production of more native-like L2 vowels after training. We also observed that not all vowels were equally acquired or affected by musical hearing or musical experience. The strongest estimate we observed was the closeness to model before training, suggesting that learners who already managed to acquire some features of a native-like accent were also more successful after training. Conclusions Our results are revealing in two aspects. First, the learners' former proficiency in L2 pronunciation is the most robust predictor in acquiring a native-like accent. Second, there is a potential relationship between rhythmic memory and L2 vowel acquisition before training, as well as years of musical experience after training, suggesting that specific musical skills and music practice can be an asset in learning a foreign language accent.

Acoustic analysis of vowel formant frequencies in genetically-related and non-genetically related speakers with implications for forensic speaker comparison

The purpose of this study was to explore the speaker-discriminatory potential of vowel formant mean frequencies in comparisons of identical twin pairs and non-genetically related speakers. The influences of lexical stress and the vowels’ acoustic distances on the discriminatory patterns of formant frequencies were also assessed. Acoustic extraction and analysis of the first four speech formants F1-F4 were carried out using spontaneous speech materials. The recordings comprise telephone conversations between identical twin pairs while being directly recorded through high-quality microphones. The subjects were 20 male adult speakers of Brazilian Portuguese (BP), aged between 19 and 35. As for comparisons, stressed and unstressed oral vowels of BP were segmented and transcribed manually in the Praat software. F1-F4 formant estimates were automatically extracted from the middle points of each labeled vowel. Formant values were represented in both Hertz and Bark. Comparisons within identical twin pairs using the Bark scale were performed to verify whether the measured differences would be potentially significant when following a psychoacoustic criterion. The results revealed consistent patterns regarding the comparison of low-frequency and high-frequency formants in twin pairs and non-genetically related speakers, with high-frequency formants displaying a greater speaker-discriminatory power compared to low-frequency formants. Among all formants, F4 seemed to display the highest discriminatory potential within identical twin pairs, followed by F3. As for non-genetically related speakers, both F3 and F4 displayed a similar high discriminatory potential. Regarding vowel quality, the central vowel /a/ was found to be the most speaker-discriminatory segment, followed by front vowels. Moreover, stressed vowels displayed a higher inter-speaker discrimination than unstressed vowels in both groups; however, the combination of stressed and unstressed vowels was found even more explanatory in terms of the observed differences. Although identical twins displayed a higher phonetic similarity, they were not found phonetically identical.

Extending automatic vowel formant extraction to New Englishes

While different automated procedures for vowel formant prediction have recently been proposed, it is unclear how reliably these methods perform in the phonetic study of vowels in New Englishes and how such approaches could be applied to specific varieties. This paper compares different automatic methods for vowel formant prediction in New Englishes, using manual measurements of Trinidadian English as a baseline. The results show that all methods perform significantly better than default formant parameters often used in speech analysis packages, and that a Bayesian formant tracker calibrated with American (US-FAVE) and Trinidadian English (TRINI-FAVE) generally provides better results than an automatic procedure that optimizes formant ceilings on a vowel- and speaker-specific level. TRINI-FAVE measures vowels characteristic of Trinidadian English most accurately. Phonetic studies of vowels in New Englishes can benefit from these methods.