Papers by Christina Hagedorn
JASA Express Letters
Individuals who have undergone treatment for oral cancer oftentimes exhibit compensatory behavior... more Individuals who have undergone treatment for oral cancer oftentimes exhibit compensatory behavior in consonant production. This pilot study investigates whether compensatory mechanisms utilized in the production of speech sounds with a given target constriction location vary systematically depending on target manner of articulation. The data reveal that compensatory strategies used to produce target alveolar segments vary systematically as a function of target manner of articulation in subtle yet meaningful ways. When target constriction degree at a particular constriction location cannot be preserved, individuals may leverage their ability to finely modulate constriction degree at multiple constriction locations along the vocal tract.
The Journal of the Acoustical Society of America, 2021
The glossectomy procedure, involving surgical resection of cancerous lingual tissue, has long bee... more The glossectomy procedure, involving surgical resection of cancerous lingual tissue, has long been observed to affect speech production. This study aims to quantitatively index and compare complexity of vocal tract shaping due to lingual movement in individuals who have undergone glossectomy and typical speakers using real-time magnetic resonance imaging data and Principal Component Analysis. The data reveal that (i) the type of glossectomy undergone largely predicts the patterns in vocal tract shaping observed, (ii) gross forward and backward motion of the tongue body accounts for more change in vocal tract shaping than do subtler movements of the tongue (e.g., tongue tip constrictions) in patient data, and (iii) fewer vocal tract shaping components are required to account for the patients' speech data than typical speech data, suggesting that the patient data at hand exhibit less complex vocal tract shaping in the midsagittal plane than do the data from the typical speakers ob...
Manual of Clinical Phonetics, 2021
The Journal of the Acoustical Society of America, 2021
Cross-language studies of speech production have shown that English speakers can produce phonotac... more Cross-language studies of speech production have shown that English speakers can produce phonotactically illegal onset fricative-nasal clusters (e.g., /fn/) with high accuracy based on acoustic analyses. However, it remains unclear whether the articulatory gestures affiliated with the fricative-nasal segments are produced with comparable gestural timing to native onset clusters (e.g., /sm/, /fl/). We here used electromagnetic articulography (EMA) to investigate whether the production of non-native /fn/ onset clusters exhibits a comparable amount of consonant-vowel gestural overlap to native onset clusters (i.e., /sm/ and /fl/) in nonwords. Previous articulatory investigations have demonstrated that native English onset clusters exhibit an increase in gestural overlap between the vowel-adjacent consonant and the vowel (e.g., SMAGDEEP) when compared to the corresponding singleton (MAGDEEP). We controlled for the vocal tract configuration (e.g., jaw position) by comparing each onset cl...
Perspectives of the ASHA Special Interest Groups, 2019
PurposeAs increasing amounts and types of speech data become accessible, health care and technolo... more PurposeAs increasing amounts and types of speech data become accessible, health care and technology industries increasingly demand quantitative insight into speech content. The potential for speech data to provide insight into cognitive, affective, and psychological health states and behavior crucially depends on the ability to integrate speech data into the scientific process. Current engineering methods for acquiring, analyzing, and modeling speech data present the opportunity to integrate speech data into the scientific process. Additionally, machine learning systems recognize patterns in data that can facilitate hypothesis generation, data analysis, and statistical modeling. The goals of the present article are (a) to review developments across these domains that have allowed real-time magnetic resonance imaging to shed light on aspects of atypical speech articulation; (b) in a parallel vein, to discuss how advancements in signal processing have allowed for an improved understan...
Journal of Speech, Language, and Hearing Research, 2019
Purpose Facial transplantation involves partial or total replacement of neuromuscular and skeleta... more Purpose Facial transplantation involves partial or total replacement of neuromuscular and skeletal structures of the face, head, and neck using donor tissues and is among the most extensive facial reconstructive procedures. This case report compares changes in speech production and articulator movement in a 44-year-old man from pretransplant to a 13-month posttransplant period. Method Speech production and articulator movement data were examined at 5 time points, once pretransplant and 4 times posttransplant (4, 7, 10, and 13 months), and compared to 4 healthy controls. A motion capture system was used to track jaw and vertical/horizontal lip movement during nonspeech and speech tasks. Speech intelligibility, jaw displacement, lip aperture, and movement variability were measured. Results Speech intelligibility varied across the study period and was restored to control status by 7 months posttransplant. Jaw displacement and lip aperture in the vertical plane significantly increased o...
This study aims to compare English closed syllables and Taiwanese checked syllables regarding bot... more This study aims to compare English closed syllables and Taiwanese checked syllables regarding both 1) intra-syllabic coordination: the timing relations between onset and coda consonants within the ...
The Journal of the Acoustical Society of America, 2011
Research on geminate consonants has attempted to establish whether the control of their articulat... more Research on geminate consonants has attempted to establish whether the control of their articulation differs from that of corresponding singletons in temporal parameters, spatial parameters, or both. One piece of evidence supporting spatial control in Italian geminates is EPG results revealing that the location of maximal constriction (CL) of coronal geminates along the palate exhibits small differences from the CL of singletons (Payne 2005). However, our recent work investigating Italian using real-time magnetic resonance imaging (MRI) has shown that when measuring CL dynamically, the CL of singletons and geminates are identical. Dynamic CL is defined as the region of the image that exhibits maximum intensity change during constriction formation and release. These results can be reconciled with the EPG findings if we hypothesize that differences in CL at the moment of maximal constriction are due to compression effects (in the longer geminates) involving the tongue tip sliding alon...
In this study the intraand inter-gestural timing and coordination in English closed syllables and... more In this study the intraand inter-gestural timing and coordination in English closed syllables and Taiwanese checked 1 syllables is examined. Kinematic data elicited from a repetition task reveals that the vowel is co-articulated with the onset and coda consonants to a greater extent in Taiwanese checked syllables than English closed syllables; for Taiwanese greater overlap is observed between the hetero-syllabic coda and onset consonants. The different gestural overlap patterns in Taiwanese and English are accounted for with reference to the language-specific gestural pattern.
Journal of speech, language, and hearing research : JSLHR, Apr 17, 2017
Real-time magnetic resonance imaging (MRI) and accompanying analytical methods are shown to captu... more Real-time magnetic resonance imaging (MRI) and accompanying analytical methods are shown to capture and quantify salient aspects of apraxic speech, substantiating and expanding upon evidence provided by clinical observation and acoustic and kinematic data. Analysis of apraxic speech errors within a dynamic systems framework is provided and the nature of pathomechanisms of apraxic speech discussed. One adult male speaker with apraxia of speech was imaged using real-time MRI while producing spontaneous speech, repeated naming tasks, and self-paced repetition of word pairs designed to elicit speech errors. Articulatory data were analyzed, and speech errors were detected using time series reflecting articulatory activity in regions of interest. Real-time MRI captured two types of apraxic gestural intrusion errors in a word pair repetition task. Gestural intrusion errors in nonrepetitive speech, multiple silent initiation gestures at the onset of speech, and covert (unphonated) articulat...
Purpose: Facial transplantation involves partial or total replacement of neuromuscular and skelet... more Purpose: Facial transplantation involves partial or total replacement of neuromuscular and skeletal structures of the face, head, and neck using donor tissues and is among the most extensive facial reconstructive procedures. This case report compares changes in speech production and articulator movement in a 44-year-old man from pretransplant to a 13-month posttransplant period. Method: Speech production and articulator movement data were examined at 5 time points, once pretransplant and 4 times posttransplant (4, 7, 10, and 13 months), and compared to 4 healthy controls. A motion capture system was used to track jaw and vertical/horizontal lip movement during nonspeech and speech tasks. Speech intelligibility, jaw displacement, lip aperture, and movement variability were measured.
<b>Purpose:</b> As increasing amounts and types of speech data become accessible, hea... more <b>Purpose:</b> As increasing amounts and types of speech data become accessible, health care and technology industries increasingly demand quantitative insight into speech content.The potential for speech data to provide insight into cognitive, affective, and psychological health states and behavior crucially depends on the ability to integrate speech data into the scientific process. Current engineering methods for acquiring, analyzing, and modeling speech data present the opportunity to integrate speech data into the scientific process. Additionally, machine learning systems recognize patterns in data that can facilitate hypothesis generation, data analysis, and statistical modeling. The goals of the present article are (a) to review developments across these domains that have allowed real-time magnetic resonance imaging to shed light on aspects of atypical speech articulation; (b) in a parallel vein, to discuss how advancements in signal processing have allowed for an improved understanding of communication markers associated with autism spectrum disorder; and (c) to highlight the clinical significance and implications of the application of these technological advancements to each of these areas.<br><b>Conclusion:</b> The collaboration of engineers, speech scientists, and clinicians has resulted in (a) the development of biologically inspired technology that has been proven useful for both small- and large-scale analyses, (b) a deepened practical and theoretical understanding of both typical and impaired speech production, and (c) the establishment and enhancement of diagnostic and therapeutic tools, all having far-reaching, interdisciplinary significance.
Purpose: Real-time magnetic resonance imaging (MRI) and accompanying analytical methods are shown... more Purpose: Real-time magnetic resonance imaging (MRI) and accompanying analytical methods are shown to capture and quantify salient aspects of apraxic speech, substantiating and expanding upon evidence provided by clinical observation and acoustic and kinematic data. Analysis of apraxic speech errors within a dynamic systems framework is provided and the nature of pathomechanisms of apraxic speech discussed. Method: One adult male speaker with apraxia of speech was imaged using real-time MRI while producing spontaneous speech, repeated naming tasks, and self-paced repetition of word pairs designed to elicit speech errors. Articulatory data were analyzed, and speech errors were detected using time series reflecting articulatory activity in regions of interest.
The Journal of the Acoustical Society of America, 2013
ABSTRACT The tongue varies across speakers in terms of the proportion of the overall speech produ... more ABSTRACT The tongue varies across speakers in terms of the proportion of the overall speech production apparatus that it occupies. Differences in tongue size have the potential to result in speaker-specific articulatory strategies for shaping the vocal tract area function and, in turn, individual patterns of vowel acoustics. The present study examines the interplay between relative tongue size and vowel production using real-time magnetic resonance imaging with synchronous audio. Two populations of native American English subjects are considered, one containing healthy adult speakers with no relevant pathologies, and another containing speakers who had undergone glossectomy as treatment for tongue cancer. All subjects were imaged in the midsagittal plane while reading phonetically balanced English sentences. The size of the tongue and the speech production apparatus were quantified from an overall average posture, and their ratio was correlated with the shape of the vowel space in terms of acoustics (e.g., formant frequencies), constrictions (i.e., location and degree of minimum constriction), and parameterized vocal tract cross-distance functions. Results indicate that relative tongue size can be used to explain and predict observable interspeaker differences in vowel production.
The Journal of the Acoustical Society of America, 2013
ABSTRACT We investigate articulatory behavior in post-glossectomy speech using real-time magnetic... more ABSTRACT We investigate articulatory behavior in post-glossectomy speech using real-time magnetic resonance imaging. Our data reveal that listeners judge speech produced by partial-glossectomy patients as atypical when the surgical procedure affected the oral tongue. Speech produced by patients whose procedure affected the base of tongue, however, was judged as typical. We observe that preservation and compensation mechanisms are exhibited by the patients with atypical speech. They preserve appropriate modulation of F1 using tongue and/or jaw height despite inability to appropriately modulate F2 due to the reduced size and/or mobility of the tongue. Further, durational differences between tense and lax vowels are maintained. The preservation of these features serves as evidence in support of a framework within which individual gestural parameters are independently controlled; when achievement of a particular parameter specification (e.g., constriction location) is compromised, the remaining (e.g., constriction degree, activation duration) are unchanged. Compensatory behavior is exhibited when coronal tongue movement has been impeded and is exemplified by (i) production of labiodental stops in place of target coronal stops and laterals and (ii) forming a velar constriction to produce frication in place of the alveolar frication for /s/.
A method of rapid, automatic extraction of consonantal articulatory trajectories from real-time m... more A method of rapid, automatic extraction of consonantal articulatory trajectories from real-time magnetic resonance image sequences is described. Constriction location targets are estimated by identifying regions of maximally-dynamic correlated pixel activity along the palate, the alveolar ridge, and at the lips. Tissue movement into and out of the constriction location is estimated by calculating the change in mean pixel intensity in a circle located at the center of the region of interest. Closure and release gesture timings are estimated from landmarks in the velocity profile derived from the smoothed intensity function. We demonstrate the utility of the technique in the analysis of Italian intervocalic consonant production.
We explore robust methods of automatically quantifying constriction location, constriction degree... more We explore robust methods of automatically quantifying constriction location, constriction degree and gestural kinematics of Italian short and long consonants using direct image analysis techniques applied to rtMRI data. Articulatory kinematics are estimated from correlated regional changes in pixel intensity. We demonstrate that these methods are capable of quantifying differences in constriction duration exhibited by short and long Italian consonants for labial, coronal and dorsal segments, and differences in constriction degree for labial and coronal consonants. No difference in constriction location is observed for geminates and singletons, while systematic differences in constriction location are observed between (i) coronal oral stops and coronal sonorants and (ii) dorsal stops flanked by vowels differing in backness.
Uploads
Papers by Christina Hagedorn