- Since my retirement from a faculty position at the University of Wisconsin-Madison, I have pursued research at the Wa... moreSince my retirement from a faculty position at the University of Wisconsin-Madison, I have pursued research at the Waisman Center, particularly in relation to (1) speech intelligibility in various clinical populations, (2) typical and atypical development of speech in children, and (3) the development and refinement of acoustic methods for the study of speech. I currently collaborate with Dr. Houri K. Vorperian on a NIH-supported project that uses MR and CT imaging along with acoustic analyses to study the anatomic development of the vocal tract in relation to its sound-producing capabilities. My research focuses on acoustic studies of typically developing speech and on the speech disorders associated with Down syndrome and cerebral palsy. I also continue to write textbooks and reference books, with two new books to be published in 2018: Clinical Phonetics, 5th edition (with Lawrence Shriberg, Tara McAllister, and Jonathan Preston) and Measuring Speech, Voice and Swallowing in the Clinic and Laboratory (with Christy Ludlow and Lincoln Gray).edit
Research Interests: Magnetic Resonance Imaging, Medicine, Early Childhood, Speech, Humans, and 15 moreMale, Infant, Normative, Mandible, Clinical Sciences, Palate, Soft Tissue, Hyoid bone, Magnetic resonance image, Child preschool, Growth Process, Larynx, Epiglottis, Paediatrics and reproductive medicine, and Oropharynx
PurposeThe anatomic origin for prepubertal vowel acoustic differences between male and female subjects remains unknown. The purpose of this study is to examine developmental sex differences in vocal tract (VT) length and its oral and... more
PurposeThe anatomic origin for prepubertal vowel acoustic differences between male and female subjects remains unknown. The purpose of this study is to examine developmental sex differences in vocal tract (VT) length and its oral and pharyngeal portions.MethodNine VT variables were measured from 605 imaging studies (magnetic resonance imaging and computed tomography) of subjects between birth and age 19 years. Given sex differences in growth rate (Vorperian et al., 2009), assessment of sex differences was done through use of a localized comparison window of 60 months. Analysis entailed applying this comparison window first to 4 discrete age cohorts, followed by a progressive assessment in which this comparison window was moved in 1-month increments from birth across all ages.ResultsFindings document significant postpubertal sex differences in both the oral and pharyngeal portions of the VT. They also document periods of significant prepubertal sex differences in the oral region firs...
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Speech motor control in normal and disordered speech , Speech motor control in normal and disordered speech , کتابخانه دیجیتال جندی شاپور اهواز
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PurposeThis study examines accuracy and comparability of 4 trademarked acoustic analysis software packages (AASPs): Praat, WaveSurfer, TF32, and CSL by using synthesized and natural vowels. Features of AASPs are also... more
PurposeThis study examines accuracy and comparability of 4 trademarked acoustic analysis software packages (AASPs): Praat, WaveSurfer, TF32, and CSL by using synthesized and natural vowels. Features of AASPs are also described.MethodSynthesized and natural vowels were analyzed using each of the AASP's default settings to secure 9 acoustic measures: fundamental frequency (F0), formant frequencies (F1–F4), and formant bandwidths (B1–B4). The discrepancy between the software measured values and the input values (synthesized, previously reported, and manual measurements) was used to assess comparability and accuracy. Basic AASP features are described.ResultsResults indicate that Praat, WaveSurfer, and TF32 generate accurate and comparable F0 and F1–F4 data for synthesized vowels and adult male natural vowels. Results varied by vowel for women and children, with some serious errors. Bandwidth measurements by AASPs were highly inaccurate as compared with manual measurements and publis...
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Speech development in children is predicated partly on the growth and anatomic restructuring of the vocal tract. This study examines the growth pattern of the various hard and soft tissue vocal tract structures as visualized by magnetic... more
Speech development in children is predicated partly on the growth and anatomic restructuring of the vocal tract. This study examines the growth pattern of the various hard and soft tissue vocal tract structures as visualized by magnetic resonance imaging (MRI), and assesses their relational growth with vocal tract length (VTL). Measurements on lip thickness, hard- and soft-palate length, tongue length, naso-oro-pharyngeal length, mandibular length and depth, and distance of the hyoid bone and larynx from the posterior nasal spine were used from 63 pediatric cases (ages birth to 6 years and 9 months) and 12 adults. Results indicate (a) ongoing growth of all oral and pharyngeal vocal tract structures with no sexual dimorphism, and a period of accelerated growth between birth and 18 months; (b) vocal tract structure’s region (oral/anterior versus pharyngeal/posterior) and orientation (horizontal versus vertical) determine its growth pattern; and (c) the relational growth of the differe...
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This study explored the speech characteristics of Mandarin-speaking children with cerebral palsy (CP) and typically developing (TD) children to determine (a) how children in the 2 groups may differ in their speech patterns and (b) the... more
This study explored the speech characteristics of Mandarin-speaking children with cerebral palsy (CP) and typically developing (TD) children to determine (a) how children in the 2 groups may differ in their speech patterns and (b) the variables correlated with speech intelligibility for words and sentences. Data from 6 children with CP and a clinical diagnosis of moderate dysarthria were compared with data from 9 TD children using a multiple speech subsystems approach. Acoustic and perceptual variables reflecting 3 speech subsystems (articulatory-phonetic, phonatory, and prosodic), and speech intelligibility, were measured based on speech samples obtained from the Test of Children's Speech Intelligibility in Mandarin (developed in the lab for the purpose of this research). The CP and TD children differed in several aspects of speech subsystem function. Speech intelligibility scores in children with CP were influenced by all 3 speech subsystems, but articulatory-phonetic variable...
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PurposeA single-word identification test was used to study speech production in children and adults with Down syndrome (DS) to determine the developmental pattern of speech intelligibility with an emphasis on vowels.MethodSpeech... more
PurposeA single-word identification test was used to study speech production in children and adults with Down syndrome (DS) to determine the developmental pattern of speech intelligibility with an emphasis on vowels.MethodSpeech recordings were collected from 62 participants with DS aged 4–40 years and 25 typically developing participants aged 4–7 years. Panels of 5 adult lay listeners transcribed the speech recordings orthographically, and their responses were scored in comparison with the speakers' target words.ResultsSpeech intelligibility in persons with DS improved with age, especially between the ages of 4 and 16 years. Whereas consonants contribute to intelligibility, vowels also played an important role in reduced intelligibility with an apparent developmental difference in low versus high vowels, where the vowels /æ/ and/ɑ/ developed at a later age than /i/ and /u/. Interspeaker variability was large, with male individuals being generally less intelligible than female i...
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This study systematically assessed the effects of select LPC analysis parameter manipulations on vowel formant measurements for diverse speaker groups using four trademarked Speech Acoustic Analysis Software Packages (SAASP): CSL, Praat,... more
This study systematically assessed the effects of select LPC analysis parameter manipulations on vowel formant measurements for diverse speaker groups using four trademarked Speech Acoustic Analysis Software Packages (SAASP): CSL, Praat, TF32, and WaveSurfer. Productions of four words containing the corner vowels were recorded from four speaker groups with typical development (male and female adults, male and female children) and four speaker groups with Down syndrome (male and female adults and male and female children). Formant frequencies were determined from manual measurements using a consensus analysis procedure to establish formant reference values, and from the four SAASP (using both the default analysis parameters and with adjustments/manipulations to select parameters). Smaller differences between values obtained from the SAASP and the consensus analysis implied more optimal analysis parameter settings. Manipulations of default analysis parameters in CSL, Praat and TF32 yi...
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PurposeSpeech and other oral functions such as swallowing have been compared and contrasted with oral behaviors variously labeledquasispeech, paraspeech, speechlike,andnonspeech,all of which overlap to some degree in neural control,... more
PurposeSpeech and other oral functions such as swallowing have been compared and contrasted with oral behaviors variously labeledquasispeech, paraspeech, speechlike,andnonspeech,all of which overlap to some degree in neural control, muscles deployed, and movements performed. Efforts to understand the relationships among these behaviors are hindered by the lack of explicit and widely accepted definitions. This review article offers definitions and taxonomies for nonspeech oral movements and for diverse speaking tasks, both overt and covert.MethodReview of the literature included searches of Medline, Google Scholar, HighWire Press, and various online sources. Search terms pertained to speech, quasispeech, paraspeech, speechlike, and nonspeech oral movements. Searches also were carried out for associated terms in oral biology, craniofacial physiology, and motor control.Results and ConclusionsNonspeech movements have a broad spectrum of clinical applications, including developmental spe...
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Few detailed reports have been published on the nature of speech and voice changes during the course of amyotrophic lateral sclerosis (ALS). The subject of this case study is a woman who was diagnosed as having ALS with bulbar signs at... more
Few detailed reports have been published on the nature of speech and voice changes during the course of amyotrophic lateral sclerosis (ALS). The subject of this case study is a woman who was diagnosed as having ALS with bulbar signs at the age of 53. Speech intelligibility, pulmonary function, and selected speech and voice functions were tested during an approximately 2-year course of her disease. Over this period, her speech intelligibility, as measured by a multiplechoice word identification test, declined from 98% to 48%. Phonetic features that were most affected during the intelligibility decline included voicing contrast for syllable-initial and syllablefinal consonants, place of articulation contrasts for lingual consonants, manner of articulation for lingual consonants, stop versus nasal manner of production, features related to the liquid consonants, and various features related to syllable shape. An acoustic measure, average slope of the second-formant frequency, declined i...
Research Interests: Psychology, Cognitive Science, Phonetics, Audiology, Speech Acoustics, and 15 moreLinguistics, Dysarthria, Phonation, Medicine, Speech, Amyotrophic Lateral Sclerosis, Humans, Female, Speech Intelligibility, Speech and Hearing, Clinical Sciences, Middle Aged, Longitudinal Studies, Time Factors, and Respiratory Mechanics
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The classification of voice disorders has been hampered by the questionable reliability of perceptual scaling methods and by the generally poor correlations between perceptual and acoustic data. This report uses a self‐organizing map to... more
The classification of voice disorders has been hampered by the questionable reliability of perceptual scaling methods and by the generally poor correlations between perceptual and acoustic data. This report uses a self‐organizing map to classify normal and disordered voices. The self‐organizing feature map (SOFM) is essentially a two‐dimensional representational mapping over an array of processing units of the multidimensional nonlinear regularities inherent in the input data space. The input data were five acoustic measures obtained from a MDVP [Multi‐Dimensional Voice Protocol, Kay Elemetrics Corp.] analysis of sustained phonations included in the Voice Disorders Database version 1.03, compiled by the Voice and Speech Laboratory, Massachusetts Eye and Ear Infirmary. The measures included: jitter percent, fundamental frequency variation, shimmer percent, noise‐to‐harmonics ratio, and amplitude of the dominant cepstral rhamonic. The SOFM was trained with three voice samples: normal, hyperfunction, and anterior–posterior squeezing. The SOFM also was used to classify voices obtained from individuals with neurogenic speech disorders (dysarthrias). [Work supported by NIH.]
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Research Interests: Psychology, Communication, Communication Disorders, Cerebral Palsy, Adolescent, and 14 moreMedicine, Humans, Child, Female, Male, Inter-rater reliability, Reproducibility of Results, CFCS, Parent‐child Relations, Motor activity, Psychomotor Performance, Disability Evaluation, Child preschool, and Medical and Health Sciences
Research Interests: Neurology, Pediatrics, Psychiatry, Child Development, Cerebral Palsy, and 15 moreAdolescent, Medicine, Physical Medicine and Rehabilitation, Humans, Child, Correlation, Female, Classification, Male, Etiology, Motor Function, Gross Motor Skill, Case Control Studies, Child preschool, and Medical and Health Sciences
ABSTRACT The relationship between speech intelligibility on a single-word identification test and the average second-formant (F2) slope of selected test words was examined for a group of 25 men and ten women with amyotrophic lateral... more
ABSTRACT The relationship between speech intelligibility on a single-word identification test and the average second-formant (F2) slope of selected test words was examined for a group of 25 men and ten women with amyotrophic lateral sclerosis (ALS). A Spearman rank-order correlation coefficient greater than 0.80 was obtained for both the male and female subjects. This moderately high correlation indicates that the F2 slope index is a useful acoustic measure of speech proficiency in ALS. F2 slope indices are reported for normal control populations of geriatric men and women. In addition, progressive deterioration of the F2 slope index is illustrated in a case study of one woman with ALS.
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PurposeThe aim of this study is to investigate how speech fluency in typical and atypical speech is perceptually assessed by speech-language pathologists (SLPs). Our research questions were as follows: (a) How do SLPs rate fluency in... more
PurposeThe aim of this study is to investigate how speech fluency in typical and atypical speech is perceptually assessed by speech-language pathologists (SLPs). Our research questions were as follows: (a) How do SLPs rate fluency in speakers with and without neurological communication disorders? (b) Do they differentiate the speaker groups? and (c) What features do they hear impairing speech fluency?MethodTen SLPs specialized in neurological communication disorders volunteered as expert judges to rate 90 narrative speech samples on a Visual Analogue Scale (see Kempster, Gerratt, Verdolini Abbott, Barkmeier-Kraemer, & Hillman, 2009; p. 127). The samples—randomly mixed—were from 70 neurologically healthy speakers (the control group) and 20 speakers with traumatic brain injury, 10 of whom had neurogenic stuttering (designated as Clinical Groups A and B).ResultsThe fluency rates were higher for typical speakers than for speakers with traumatic brain injury; however, the agreement among...
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Speech-language pathology relies on auditory-perceptual judgment as a central tool for classifying and measuring a variety of disorders of communication. Over the history of the field, a great deal has been written about the use of... more
Speech-language pathology relies on auditory-perceptual judgment as a central tool for classifying and measuring a variety of disorders of communication. Over the history of the field, a great deal has been written about the use of perceptual judgments for research and clinical practice. Auditory-perceptual methods carry strong advantages of convenience, economy, and robustness, but it is also clear that these judgments are susceptible to a variety of sources of error and bias. Awareness of these threats to validity and reliability is a major step in the effective and refined use of perceptual methods. Several common themes are evident in contemporary research on the perceptual assessment of voice disorders, stuttering, dysarthria, aphasia, and apraxia of speech. These five disorders are taken as primary foci in a discussion that (a) identifies threats to reliability and validity, and (b) offers suggestions for the improvement of auditory-perceptual methods, whether used alone or in...
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The present study investigates the accuracy of perceptually and acoustically determined inspiratory loci in spontaneous speech for the purpose of identifying breath groups. Sixteen participants were asked to talk about simple topics in... more
The present study investigates the accuracy of perceptually and acoustically determined inspiratory loci in spontaneous speech for the purpose of identifying breath groups. Sixteen participants were asked to talk about simple topics in daily life at a comfortable speaking rate and loudness while connected to a pneumotach and audio microphone. The locations of inspiratory loci were determined on the basis of the aerodynamic signal, which served as a reference for loci identified perceptually and acoustically. Signal detection theory was used to evaluate the accuracy of the methods. The results showed that the greatest accuracy in pause detection was achieved (1) perceptually, on the basis of agreement between at least two of three judges, and (2) acoustically, using a pause duration threshold of 300 ms. In general, the perceptually based method was more accurate than was the acoustically based method. Inconsistencies among perceptually determined, acoustically determined, and aerodyn...
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Research Interests: Psychology, Cognitive Science, Communication Disorders, Motor Control, Speech Disorders, and 13 moreAdolescent, Dysarthria, Stuttering, Prospective studies, Humans, Evaluation methods, Intervention, Classification, Etiology, Clinical Sciences, Motor Function, Psychomotor Skills Education, and Child preschool
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Research Interests: Psychology, Cognitive Science, Acoustics, Phonology, Communication Disorders, and 15 morePhonetics, Typology, Speech Production, Speech Acoustics, Dysarthria, Phonation, Humans, Evaluation methods, Clinical Sciences, Qualitative Analysis, Time Factors, Reproducibility of Results, Articulation, Acoustic Analysis, and Vocal cords
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... palsy (Platt, Andrews, & Howie, 1980; Platt, Andrews, Young, & Quinn, 1980); and spasmodic torticollis (LaPointe, Case, & Duane, 1994 ... Pollak, 1998; Poluha, Teulings, & Brookshire, 1998), bilateral or unilateral... more
... palsy (Platt, Andrews, & Howie, 1980; Platt, Andrews, Young, & Quinn, 1980); and spasmodic torticollis (LaPointe, Case, & Duane, 1994 ... Pollak, 1998; Poluha, Teulings, & Brookshire, 1998), bilateral or unilateral pallidotomy for Parkinson's disease (Ghika et al., 1999; Schrag et al ...
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Clinical Linguistics & Phonetics (CLP) and its namesake field have accomplished a great deal in the last quarter of a century. The success of the journal parallels the growth and vitality of the field it... more
Clinical Linguistics & Phonetics (CLP) and its namesake field have accomplished a great deal in the last quarter of a century. The success of the journal parallels the growth and vitality of the field it represents. The markers of journal achievement are several, including increased number of journal pages published annually; greater diversity of topics related to the core mission of the journal; expanding cross-language coverage; and healthy interactions among editors, reviewers and contributors; and - for better or worse - journal impact factors. A journal is in a competitive dynamic with other journals that share its general domain of scholarship, which is a major reason why an apparent imbalance may emerge in the topic content of any particular journal. The content of a journal is determined by the nature and number of submitted manuscripts. As far as linguistic content goes, CLP's centre of gravity appears to have been mostly in phonology and phonetics, but certainly not to the exclusion of syntax, semantics and pragmatics. The clinical scope is broad, both in terms of concepts and types of disorder. CLP has secured its place among journals in the field, and it is an outlet of choice for many researchers throughout the world.
Research Interests: History, Intellectual History, Cognitive Science, Speech Language Pathology, Phonology, and 14 morePhonetics, Pragmatics, Semantics, Syntax, Applied Linguistics, Linguistics, Periodicals, Language disorders, Reputation, Humans, A Short History of Clinical Linguistics and Phonetics, Clinical Sciences, Publications, and Publication
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This paper describes cineradiographic techniques for the assessment of articulatory mobility in dysarthric subjects. Sample data for the mobility ranges of articulatory points on the tongue, lower lip, and jaw are presented for four... more
This paper describes cineradiographic techniques for the assessment of articulatory mobility in dysarthric subjects. Sample data for the mobility ranges of articulatory points on the tongue, lower lip, and jaw are presented for four normal speakers and four dysarthric speakers. In addition, fleshpoint displacements during the articulatory movements of the dysarthric subjects are used to illustrate abnormalities in the range, rate, and direction of speech movements. Discussion of the point-parameterized cineradiographic data emphasizes possibilities for the clinical evaluation of dysarthric impairments.
Performance characteristics are reviewed for seven systems marketed for acoustic speech analysis: CSpeech, CSRE, ILS-PC, Kay Elemetrics model 5500 Sona-Graph, MacSpeech Lab II, MSL, and Signalyze. The characteristics reviewed include... more
Performance characteristics are reviewed for seven systems marketed for acoustic speech analysis: CSpeech, CSRE, ILS-PC, Kay Elemetrics model 5500 Sona-Graph, MacSpeech Lab II, MSL, and Signalyze. The characteristics reviewed include system components, basic capabilities (signal acquisition, waveform operations, analysis, and other functions), documentation, user interface, data formats and journaling, speed and precision of spectral analysis, and speed and precision of fundamental frequency analysis. Basic capabilities are also tabulated for three recently introduced systems: the Sensimetrics SpeechStation, the Kay Elemetrics Computerized Speech Lab (CSL), and the LSI Speech Workstation. In addition to the capability and performance summaries, this article offers suggestions for continued development of speech analysis systems, particularly in data exchange, journaling, display features, spectral analysis, and fundamental frequency analysis.
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This study describes the effects of listener proficiency and familiarization on judgments of speech intelligibility and speech severity associated with a progressive dysarthria. Speech performance was followed longitudinally for 39 months... more
This study describes the effects of listener proficiency and familiarization on judgments of speech intelligibility and speech severity associated with a progressive dysarthria. Speech performance was followed longitudinally for 39 months postdiagnosis for a man with ALS. The subject’s spouse served as a highly familiar listener whose speech severity and intelligibility judgments were compared to those of 24 unfamiliar listener-judges. The expected superior ratings of the spouse over the unfamiliar listeners became especially evident at 20 months postdiagnosis when the speech disorder was moderately severe. That is, the advantage of familiarity evolved over time and reached its maximum when the speech impairment was marked. Results for the unfamiliar listener group illustrated that differences among judges represented large individual variations in listener proficiency. These results have clinical significance in that they suggest the use of a practice standard for progressive dysar...