Thomas P. Marquardt

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The phonological competence of four children, aged 5-7 years old, who demonstrated a cluster of symptoms consistent with a diagnosis of developmental apraxia of speech (DAS), was contrasted to that of four normal children. Four rhyming tasks were used to assess the ability of the children to both spontaneously generate rhyming words to targets and to judge(More)
Variability in the speech production patterns of children with developmental apraxia of speech (DAS) was investigated in a three-year longitudinal study of three children with DAS. A metric was developed to measure token-to-token variability in repeated word productions from connected speech samples. Results suggest that high levels of total token and error(More)
UNLABELLED Changes in consonant and syllable-level error patterns of three children diagnosed with childhood apraxia of speech (CAS) were investigated in a 3-year longitudinal study. Spontaneous speech samples were analyzed to assess the accuracy of consonants and syllables. Consonant accuracy was low overall, with most frequent errors on middle- and(More)
UNLABELLED Three children with developmental apraxia of speech (DAS) identified the number of syllables in words, judged intrasyllabic sound positions, and constructed syllable shapes within monosyllabic frames. Results suggest that DAS children demonstrate an apparent breakdown in the ability to perceive "syllableness" and to access and compare syllable(More)
Conversational discourse samples were obtained from four aphasic and four neurologically normal Hispanic bilinguals in monolingual English, monolingual Spanish, and bilingual contexts to identify codeswitching patterns. Analysis of the samples based on the Matrix Language Frame (MLF) Model (Myers-Scotton, 1993a) revealed consistent matching of the language(More)
Vowel inventories and error patterns for three children with suspected developmental apraxia of speech (DAS) were analysed over a 3-year period using phonetic transcriptions of connected speech samples. The children demonstrated complete English vowel inventories except for rhotics. However, accuracy of vowel targets in connected speech did not normalize(More)
The errors of ten apraxic speakers on a single word task were analyzed to determine the effects of articulatory and linguistic variables on speech production. Results suggested that phoneme difficulty but not phoneme position or grammatical class significantly affected the errors of the subjects. A significant low positive correlation between mean word(More)
Ten adults with apraxia of speech responded to sentences of an article (pronoun) + noun + verb + article (pronoun) + noun design. Each sentence was presented and then re-presented with the noun in Noun Phrase 1 (NP1) or Noun Phrase 2 (NP2) omitted. The subjects' task was to orally produce the omitted word. Sentences were either active or passive and the(More)
The purpose of the study was to investigate the intelligibility of two voice output communication aids. Twenty words and 20 sentences, synthesized with the Personal Communicator and with the SpeechPAC, were presented to 20 listeners. Listener transcriptions of the stimuli were used to compare the intelligibility of the two communication aids. Analysis of(More)
Thirteen patients clinically diagnosed as Broca's aphasics, were administered a vowel bite block task to ascertain their on-line compensatory articulation ability. Formant frequencies for F1 and F2 were obtained from a pitch-synchronous spectral analysis of digitized vowel waveforms. Bite block/i/productions were consistently characterized by higher F1 and(More)