About

Professor Ratree Wayland is a faculty member in the Department of Linguistics at the College of Liberal Arts and Sciences, University of Florida. Her research focuses on cross-language speech perception and production, with particular attention to lexical tone processing and acquisition. She specializes in Southeast Asian languages, as well as Sino-Tibetan and Austroasiatic languages. Additionally, Professor Wayland investigates the use of speech as biomarkers for neurological, cognitive, and psychiatric disorders. Her work also encompasses natural language processing, integrating linguistic insights with computational methods. She maintains an active role in both research and teaching within her department.

Research topics

• Computer Science
• Speech recognition
• Artificial Intelligence
• Linguistics
• Psychology
• Communication
• Visual arts
• Mathematics
• Art
• Acoustics
• Audiology
• Physics
• Philosophy
• Medicine
• Neuroscience

Selected publications

• Near-Merger and Contextual Sensitivity in the Perception of /n-l/ in Sichuan Mandarin

  Brain Sciences · 2026-01-29

  articleOpen accessSenior authorCorresponding

  Background/Objectives: Sichuan Mandarin is often described as exhibiting overlap or merger between word-initial /n/ and /l/, but perceptual sensitivity across phonetic contexts remains underexplored. This study examines whether perception of the /n-l/ contrast varies by vowel context and listener experience. Methods: Thirty-two Sichuan Mandarin listeners completed categorical identification and same–different AX discrimination tasks using seven-step /n/ → /l/ continua derived from native-speaker productions in /i/ and /a/ contexts. Sensitivity, response bias, accuracy, and response times were analyzed alongside individual differences. Acoustic properties of the stimuli were quantified using spectral and amplitude-based measures. Results: Listeners showed overall reduced sensitivity to the /n-l/ contrast, with substantially stronger perceptual differentiation in /i/ than in /a/ contexts. Bias patterns were comparable across contexts, indicating sensitivity-driven effects. Acoustic analyses showed more robust cue structure in the /i/ continuum. Age, education, and Standard Mandarin experience modulated response efficiency but did not eliminate the vowel asymmetry. Conclusions: Results support a context-dependent near-merger of /n/ and /l/, shaped by acoustic cue availability and experience-based cue exploitation.

  PublisherOA PDFDOI

• Phonological Feature Posteriors and Cue-Specific Accent Perception in Hindi- and Tamil-Accented English

  Brain Sciences · 2026-01-31

  articleOpen accessSenior author

  Background/Objectives: Accented speech reflects systematic deviation from target-language phonetic norms. This study demonstrates that perceived accent strength covaries with selective, gradient differences in phonological feature realization. We examine whether perceived accents in Hindi- and Tamil-accented English reflect uniform segmental deviation or cue-specific patterns of phonological feature realization. Methods: English speech produced by native speakers of Hindi and Tamil was evaluated using native listener accentedness ratings. Phonetic variation was analyzed using posterior probabilities of phonological features derived from a machine learning model, Phonet. The analyses focused on liquids (laterals and rhotics (e.g., /l/, /ɭ/, and /ɻ/) and labial segments in the fricative–glide space (e.g., /v/, /w/, and /ʋ/), with attention to word position and feature-level generalization. Results: Accentedness ratings differed systematically for Hindi- and Tamil-accented English and covaried with a subset of phonological feature dimensions, yielding contrast- and context-specific patterns of perceptually relevant variation. Not all features that varied in production contributed to perceived accent strength. Conclusions: These findings support a cue-specific, perception-grounded account of accentedness and establish phonological feature posteriors derived from Phonet as interpretable phonological categories through which gradient L2 production differences are evaluated by listeners.

  PublisherOA PDFDOI

• Factors Affecting Stress Placement for English Nonwords Include Syllabic Structure, Lexical Class, And Stress Patterns Of Phonologically Similar Words

  2026-01-06

  book-chapterSenior author

  Seventeen native English speakers participated in an investigation of language users’ knowledge of English main stress patterns. First, they produced 40 two-syllable nonwords of varying syllabic structure as nouns and verbs. Second, they indicated their |preference for first or second syllable stress of the same words in a perception task. Finally, they indicated words they considered to be phonologically similar to the nonwords. Analyses of variance on the production and perception data indicated that both syllabic structure and lexical class (noun or verb) had an effect on main stress assignment. In logistic regression analyses on the production and perception responses, predictions of stress placement made by (1) syllable structure, (2) lexical class, and (3) stress patterns of phonologically similar words all contributed significantly and uniquely to the prediction of main stress assignment. The results indicate that phonological theories of English word stress need to allow for multiple, competing, probabilistic factors in accounts of main stress placement including syllabic structure (most notably vowel length), lexical class, and stress patterns of phonologically similar words.

  PublisherDOI

• Near-Merger and Contextual Sensitivity in the Perception of /n–l/ in Sichuan Mandarin

  Preprints.org · 2026-01-23

  preprintOpen accessSenior author

  Background/Objectives: Sichuan Mandarin is often described as exhibiting overlap or merger between word-initial /n/ and /l/, but perceptual sensitivity across phonetic contexts remains underexplored. This study examines whether perception of the /n–l/ contrast varies by vowel context and listener experience. Methods: Thirty-two Sichuan Mandarin listeners completed categorical identification and same–different AX discrimination tasks using seven-step /n/→/l/ continua derived from native-speaker productions in /i/ and /a/ contexts. Sensitivity, response bias, accuracy, and response times were analyzed alongside individual differences. Acoustic properties of the stimuli were quantified using spectral and amplitude-based measures. Results: Listeners showed overall reduced sensitivity to the /n–l/ contrast, with substantially stronger perceptual differentiation in /i/ than /a/ context. Bias patterns were comparable across contexts, indicating sensitivity-driven effects. Acoustic analyses showed more robust cue structure in the /i/ continuum. Age, education, and Standard Mandarin experience modulated response efficiency but did not eliminate the vowel asymmetry. Conclusions: Results support a context-dependent near-merger of /n/ and /l/, shaped by acoustic cue availability and experience-based cue exploitation.

  PublisherOA PDFDOI

• Perception of /n–l/ in Sichuan Mandarin

  OSF Preprints (OSF Preprints) · 2026-01-24

  other1st authorCorresponding
  Publisher

• Speech Markers of Parkinson’s Disease: Phonological Features and Acoustic Measures

  Brain Sciences · 2025-10-29 · 1 citations

  articleOpen access1st authorCorresponding

  Background/Objectives: Parkinson’s disease (PD) affects both articulatory and phonatory subsystems, leading to characteristic speech changes known as hypokinetic dysarthria. However, few studies have jointly analyzed these subsystems within the same participants using interpretable deep-learning-based measures. Methods: Speech data from the PC-GITA corpus, including 50 Colombian Spanish speakers with PD and 50 age- and sex-matched healthy controls were analyzed. We combined phonological feature posteriors—probabilistic indices of articulatory constriction derived from the Phonet deep neural network—with harmonics-to-noise ratio (HNR) as a laryngeal measure. Linear mixed-effects models tested how these measures related to disease severity (UPDRS, UPDRS-speech, and Hoehn and Yahr), age, and sex. Results: PD participants showed significantly higher [continuant] posteriors, especially for dental stops, reflecting increased spirantization and articulatory weakening. In contrast, [sonorant] posteriors did not differ from controls, indicating reduced oral constriction without a shift toward more open, approximant-like articulations. HNR was predicted by vowel height and sex but did not distinguish PD from controls, likely reflecting ON-medication recordings. Conclusions: These findings demonstrate that deep-learning-derived articulatory features can capture early, subphonemic weakening in PD speech—particularly for coronal consonants—while single-parameter laryngeal indices such as HNR are less sensitive under medicated conditions. By linking spectral energy patterns to interpretable phonological categories, this approach provides a transparent framework for detecting subtle articulatory deficits and developing feature-level biomarkers of PD progression.

  PublisherDOI

• Historical Models and Theories of Speech Learning

  The Encyclopedia of Applied Linguistics · 2025-12-02

  other1st authorCorresponding

  Abstract Speech is the most effective means to communicate thoughts, ideas, and experiences. Unlike native language (L1) learners, adult speakers of a second language (L2) rarely produce consonants, vowels, or suprasegmental features of the target language without a detectable foreign accent. The causes of this ubiquitous and complex phenomenon have been a subject of theoretical debate and empirical research for many decades, resulting in several theoretical models of cross‐linguistic speech learning. Four prominent models focusing on segmental learning, namely the Perceptual Assimilation Model (PAM), the Speech Learning Model (SLM), the Second Language Linguistic Perception model (L2LP), and the Native Language Magnet (NLM) model, are presented. These models share the assumption that second language speech acquisition is shaped, at least initially, by the phonological system of the native language. Two of the models focus on the initial state of learning (PAM and NLM) while the other two aim to account for L2 perception learning across the lifespan (SLM), and developmental processes from naive to advanced, native‐like performance (L2LP), respectively. These models also differ in their assumption about whether articulatory gestures (PAM) or acoustic and auditory features (SLM, L2LP, NLM) constitute speech sound representations and whether the representations are stored in long‐term memory. The processing level assumed in the model (e.g., auditory, phonetic, phonemic, lexical) and how the L1–L2 relationship is characterized (i.e., copying, mapping, assimilating) also differ. Finally, except for PAM, these models have not been extended to explain learning of L2 prosodic features (i.e., stress, tone, intonation, rhythm).

  PublisherDOI

• Beyond the binary: Investigating gradient palatalization in Russian with deep learning models

  The Journal of the Acoustical Society of America · 2025-04-01

  articleSenior author

  Recent research demonstrates that posterior probabilities of phonological features derived from deep learning models, such as Phonet (Vásquez-Correa et al., 2019), reliably quantify phonetic variation, with applications in linguistic analyses (e.g., Spanish lenition) and clinical diagnostics (e.g., distinguishing Parkinson’s Disease from Atypical Parkinsonism; Wayland et al., 2024, 2023). Building on this framework, our study examines gradience in Russian secondary palatalization, traditionally characterized as a binary distinction between palatalized and non-palatalized consonants. However, emerging research challenges this binary view, revealing context-dependent gradient variation (Parker, 2015), with articulatory evidence supporting incomplete neutralization of the plain-palatal contrast in Russian (Oh et al., 2024). Using the 1240-h Russian spoken corpus (Karpov et al., 2021), we train a deep learning model to derive posterior probabilities for phonological features, such as [ + high, −back], tied to palatalization (Padgett et al., 2024). This enables a detailed analysis of gradient patterns across consonant types and vocalic contexts. Our findings are expected to reveal a continuum of palatalization influenced by phonetic factors, supporting a gradient contrast utilization perspective (Parker, 2015). This study underscores the value of probabilistic approaches in capturing phonetic gradience, bridging computational methods and phonological theory, and advancing understanding of phonetic patterns in Russian and beyond.

  PublisherDOI

• Individual differences in language acquisition: The impact of study abroad on native English speakers learning Spanish

  Speech Communication · 2025-09-02 · 1 citations

  articleOpen access1st author

  • Studying abroad influences the acquisition of Spanish lenition in native English speakers. • Voicing is the primary factor affecting lenition in both native and non-native speakers. • L2 learners produce fricative-like forms more frequently than approximant-like forms. • Individual differences shape learners' phonological development during immersion. • Studying abroad alone does not guarantee native-like lenition patterns in L2 learners. This study investigated the acquisition of lenition in Spanish voiced stops (/b, d, ɡ/) by native English speakers during a study-abroad program, focusing on individual differences and influencing factors. Lenition, characterized by the weakening of stops into fricative-like ([β], [ð], [ɣ]) or approximant-like ([β̞], [ð̞], [ɣ̞]) forms, poses challenges for L2 learners due to its gradient nature and the absence of analogous approximant forms in English. Results indicated that learners aligned with native speakers in recognizing voicing as the primary cue for lenition, yet their productions diverged, favoring fricative-like over approximant-like realizations. This preference reflects the combined influence of articulatory ease, acoustic salience, and cognitive demands. Individual variability in learners’ trajectories highlights the role of exposure to native input and sociolinguistic engagement. Learners benefitting from richer, informal interactions with native speakers showed greater alignment with native patterns, while others demonstrated more limited progress. However, native input alone was insufficient for learners to internalize subtler distinctions such as place of articulation and stress. These findings emphasize the need for combining immersive experiences with targeted instructional strategies to address articulatory and cognitive challenges. This study contributes to the understanding of L2 phonological acquisition and offers insights for designing more effective language learning programs to support lenition acquisition in Spanish.

  PublisherDOI

• Monophthongization of diphthongs in Southern American English: A perception study

  The Journal of the Acoustical Society of America · 2025-04-01

  articleSenior author

  The monophthongization of /ai/ is more prevalent than /au/ in Southern American English due to historical, phonetic, and sociolinguistic factors. Phonetically, the tongue movement for /ai/ (low to high front) may be more prone to reduction than for /au/ (low to high back). Sociolinguistically, these changes often signal regional identity. This study investigates the monophthongization of /ai/ to /a/ and /au/ to /a/ in Southern English through two 11-step continua ([a-ai] and [a-au]) presented to listeners for identification. Preliminary data from 4 Southerners and 12 non-Southerners partially support the hypothesis that Southerners perceive /a/ more in the /a-ai/ continuum. Boundary positions for both continua were similar across groups, but Southern speakers showed narrower boundary widths for /a-au/ (M = 0.854) compared to /a-ai/ (M = 1.188), indicating clearer perceptual distinctions for /a-au/. Non-Southerners exhibited consistent boundary widths for /a-ai/ (M = 1.318) and /a-au/ (M = 1.335), suggesting stable perceptual systems unaffected by dialectal variation. These findings reveal that the monophthongization of /ai/ in Southern English reduces perceptual precision, reflecting its greater susceptibility to dialectal variation. In contrast, non-Southerners maintain uniform perceptual precision across continua, highlighting regional dialects' impact on phonetic perception.

  PublisherDOI

Frequent coauthors

• Si Chen

  Google (United States)

  20 shared

• Fenqi Wang

  19 shared

• Kevin Tang

  Heinrich Heine University Düsseldorf

  18 shared

• Edith Kaan

  16 shared

• Rahul Sengupta

  University of Florida

  14 shared

• Takeshi Nozawa

  Ritsumeikan University

  13 shared

• Sophia Vellozzi

  University of Florida

  12 shared

• Yiqing Zhu

  University of Florida

  10 shared

Education

• Ph.D, Linguistics

  Cornell University

  1997