Publications
Peer-Reviewed Journal Articles (chronological order)
- Zajac, D.J., & Linville, R. Voice perturbations of children with perceived nasality and hoarseness. Cleft Palate Journal, 26:226-231, 1989.
- Zajac, D.J., & Yates, C. Accuracy of the pressure-flow method in estimating induced velopharyngeal orifice area: Effects of the flow coefficient. Journal of Speech and Hearing Research, 34:1073-1078, 1991.
- Fornataro, L., & Zajac, D.J. Aerodynamic characteristics of tracheostomy speaking valves. Journal of Speech and Hearing Research, 30:529-532, 1993.
- Vig, P., & Zajac, D.J. Age and gender effects on nasal respiratory function in normal subjects. Cleft Palate-Craniofacial Journal, 30:279-284, 1993.
- Zajac, D.J., Farkas, Z., Dindzans, L., & Stool, S. Aerodynamic and laryngographic assessment of pediatric vocal function. Pediatric Pulmonology, 15:44-51, 1993.
- Zajac, D.J. Laryngeal airway resistance in children with cleft palate and adequate velopharyngeal function. Cleft Palate-Craniofacial Journal, 32:138-144, 1995.
- Warren, D.W., Mayo, R., Zajac, D.J., & Rochet, A. Dyspnea following experimentally induced increased nasal airway resistance. Cleft Palate-Craniofacial Journal, 33:231-235, 1996.
- Zajac, D.J., & Mayo, R. Aerodynamic and temporal aspects of velopharyngeal function in normal speakers. Journal of Speech and Hearing Research, 39:1199-1207, 1996.
- Zajac, D.J., Lutz, R., & Mayo, R. Microphone sensitivity as a source of variation in nasalance scores. Journal of Speech and Hearing Research, 39:1228-1231, 1996.
- Zajac, D.J., Mayo, R., Kataoka, R., & Kuo, J. Aerodynamic and acoustic characteristics of a speaker with turbulent nasal emission: A case report. Cleft Palate-Craniofacial Journal, 33:440-444, 1996.
- Kim, J.R., Zajac, D.J., Warren, D.W., Mayo, R., & Essick, G. The response to sudden change in vocal tract resistance during stop consonant production. Journal of Speech, Language, and Hearing Research, 40:848-857, 1997.
- Zajac, D.J. Velopharyngeal function in young and older adult speakers: Evidence from aerodynamic studies. Journal of the Acoustical Society of America, 102:1846-1852, 1997.
- Mayo, R., Warren, D.W., & Zajac, D.J. Intraoral pressure and velopharyngeal function. Cleft Palate-Craniofacial Journal, 35:299-303, 1998.
- Zajac, D.J. Effects of a pressure target on laryngeal airway resistance in children. Journal of Communication Disorders, 31:201-213, 1998.
- Zajac, D.J., Mayo, R., & Kataoka, R. Nasal coarticulation in normal speakers: A re-examination of the effects of gender. Journal of Speech, Language, and Hearing Research, 41:503-510, 1998.
- Hammond, C., Warren, D.W., Mayo, R., & Zajac, D.J. Respiratory responses to sudden pressure venting during stop consonant production. Folia Phoniatrica et Logopaedica, 51:250-260, 1999.
- Zajac, D.J., Fornataro-Clerici, L., & Roop, T. Aerodynamic characteristics of tracheostomy speaking valves: An updated report. Journal of Speech, Language, and Hearing Research, 42:92-100, 1999.
- Bloom, K., Zajac, D.J., & Titus, J. The influence of nasality of voice on sex-stereotyped attributions. Journal of Nonverbal Behavior, 23:271-282, 1999.
- Zajac, D.J. Pressure-flow characteristics of /m/ and /p/ production in speakers without cleft palate: Developmental findings. Cleft Palate-Craniofacial Journal, 37:468-477, 2000.
- Kataoka, R., Warren, D.W., Zajac, D.J., Mayo, R., & Lutz, R. The relationship between spectral characteristics and perceived hypernasality in children. Journal of the Acoustical Society of America, 109:2181-2189, 2001.
- Kataoka, R., Zajac, D.J., Mayo, R., Lutz, R., & Warren, D.W. The influence of acoustic and perceptual factors on perceived hypernasality in the vowel /i/: A preliminary study. Folia Phoniatrica et Logopaedica, 53:198-212, 2001.
- Smith Hammond, C., Goldstein, L., Zajac, D.J., Gray, L., Davenport, P., & Bolser, D. Assessment of aspiration risk in stroke patients with quantification of voluntary cough. Neurology, 56:502-506, 2001.
- Young, L., Zajac, D.J., Mayo, R., & Hooper, C. Effects of vowel height and vocal intensity on anticipatory nasal airflow in individuals with normal speech. Journal of Speech, Language, and Hearing Research, 44:52-60, 2001.
- Zajac, D.J., & Hackett, A. Temporal characteristics of aerodynamic segments in the speech of children and adults. Cleft Palate-Craniofacial Journal, 39:432-438, 2002.
- Agarwal, T., Sloan, G.M., Zajac, D.J., Uhrich, K.S., Meadows, W., & Lewchalermwong, J.A. Speech benefits of posterior pharyngeal flap are preserved after surgical flap division for obstructive sleep apnea: Experience with division of 12 flaps. Journal of Craniofacial Surgery, 14:630-636, 2003.
- Zajac, D.J, & Weissler, M. Air pressure responses to sudden vocal tract pressure bleeds during production of stop consonants: New evidence of aeromechanical regulation. Journal of Speech, Language, and Hearing Research, 47:784-801, 2004.
- Bundy, E., & Zajac, D.J. Estimation of transpalatal nasalance during production of voiced stop consonants by non-cleft speakers using an oral-nasal mask. Cleft Palate-Craniofacial Journal, 43:691-701, 2006.
- Gross, R., Steinhauer, K., Zajac, D.J., & Weissler, M. Direct measurement of subglottic air pressure while swallowing. The Laryngoscope, 116(5):753-761, 2006.
- Zajac, D.J., Roberts, J., Hennon, E., Harris, A., Barnes, E., & Misenheimer, J. Articulation rate and vowel space characteristics of young males with fragile X syndrome: Preliminary acoustic findings. Journal of Speech, Language, and Hearing Research, 49:1147-1155, 2006.
- Mandulak, K.C., & Zajac, D.J. Effects of altered fundamental frequency on Nasalance during vowel production by adult speakers at targeted sound pressure levels. Cleft Palate-Craniofacial Journal, 46:39-46, 2009.
- Zajac, D.J., Harris, A.A., Roberts, J.A., & Martin, G.E. Direct magnitude estimation of articulation rate in boys with fragile X syndrome. Journal of Speech, Language, and Hearing Research, 52:1370-1379, 2009.
- Gauster, A., Yunusova, Y., & Zajac, D.J. The effect of speaking rate on velopharyngeal function in healthy speakers. Clinical Linguistics & Phonetics, 24(7):576-588, 2010.
- Haley, K.L., Seelinger, E., Callahan Mandulak, K., & Zajac, D.J. Evaluating the spectral distinction between sibilant fricatives through a speaker-centered approach (Letter to the Editor). Journal of Phonetics, 38:548–554, 2010.
- Zajac, D.J., Plante, C., Lloyd, M., & Haley, K.L. Reliability and validity of a computer mediated single-word intelligibility test: Preliminary findings for children with repaired cleft lip and palate. Cleft Palate Craniofacial Journal, 48:538-549, 2011.
- Zajac, D.J., Cevidanes, L., Shah, S., & Haley, K. Maxillary arch dimensions and spectral characteristics of children with cleft lip and palate who produce middorsum palatal stops. Journal of Speech, Language, and Hearing Research, 55:1876-1886, 2012.
- Gross, R.D., Carrau, R.L., Slivka, W.A., Gisser, R.G., Smith, L.J., Zajac, D.J., & Sciurba, F.C. Deglutitive subglottic air pressure and respiratory system recoil. Dysphagia, 27(4):452-459, 2012.
- Eshghi, M., Zajac, D.J., Bijankhan, M., & Shirazi, M. Spectral analysis of word-initial alveolar and velar plosives produced by Iranian children with cleft lip and palate. Clinical Linguistics & Phonetics, 27(3):213-219, 2013.
- Krochmal, D., Zajac, D.J., Alhudaib, O., Emodi, O., & van Aalst, J. The assessment of velopharyngeal function using nasal ram pressure testing following palatoplasty. Cleft Palate-Craniofacial Journal, 50:542-547, 2013.
- Zajac, D.J. Nasalance scores of children with repaired cleft palate who exhibit normal velopharyngeal closure during aerodynamic testing. American Journal of Speech Language Pathology, 22:572-576, 2013.
- Zajac, D.J., & Milholland, S. Abrupt laryngeal engagement during stop plosive-vowel transitions in children with repaired cleft palate and adequate velopharyneal closure: Aerodynamic and sound pressure level evidence. Cleft Palate-Craniofacial Journal, 51:98-104, 2014.
- Zajac, D.J. The nature of nasal fricatives: Articulatory-perceptual characteristics and etiologic considerations. Perspectives on Speech Science and Orofacial Disorders, 25:7–28, 2015.
- Zajac, D.J., & Preisser, J. Age and phonetic influences on velar flutter as a component of nasal turbulence in children with repaired cleft palate. Cleft Palate-Craniofacial Journal, 53(6):649-656, 2016.
- Eshghi, M., Alemi, M., & Zajac, D.J. Aerodynamic and laryngeal characteristics of place-dependent voice onset time differences. Folia Phoniatrica et Logopaedica, 68(5):239-246, 2016.
- Eshghi, M., Preisser, J., Bijankhan, M., & Zajac, D.J. Acoustic-temporal aspects of stop-plosives in the speech of Persian-speaking children with cleft lip and palate. International Journal of Speech Language Pathology, 19(6):578-586, 2017.
- Eshghi, M., Vallino, L.D., Baylis, A.L., Preisser, J.S., & Zajac, D.J. Velopharyngeal status of stop consonants and vowels produced by young children with and without repaired cleft palate at 12, 14, and 18 months of age: A preliminary analysis. Journal of Speech, Language, and Hearing Research, 60:1467-1476, 2017.
- Zajac, D.J., & Eshghi, M. Vocal loudness as contributory to the occurrence of obligatory posterior nasal turbulence: Case reports. Cleft Palate-Craniofacial Journal, 55(2):301-306, 2018.
- Zajac, D.J. Obligatory nasal turbulence as a trigger for the development of posterior nasal fricatives in a child with repaired cleft palate. Cleft-Palate Craniofacial Journal, 56(5):690-696, Oct, 2018 [Epub ahead of print].
- Eshghi, M., Adatorwovor, R., Preisser, J. S., Crais, E. R., & Zajac, D. J. Vocabulary growth from 18 to 24 months of age in children with and without repaired cleft palate. J Speech Lang Hear Res, 62(9):3413-3430, 2019.
- Baylis, A., Vallino, L.D., Powell, J., & Zajac, D.J. Lexical selectivity of 2-year-old children with and without repaired cleft palate based on parent report. Cleft Palate Craniofac J, 57(9):1117-1124, 2020.
- Zajac, D.J., Vallino, L.D., Baylis, A.L., Adatorwovor, R., Preisser, J.S., & Vivaldi, D. Emergence of prevocalic stop consonants in children with repaired cleft palate. J Speech Lang Hear Res, 64(1):30-39, 2021.
- Eshghi, M., Adatorwovor, R., Preisser, J.S., Crais, E.R., & Zajac, D.J. Lexicogrammatical skills in 2-year-old children with and without repaired cleft palate. Clin Linguist Phon, Jul 15:1-19, 2021 Epub ahead of print.
- Zajac, D.J., Powell, J., & Perotta, L. The palatal closure efficiency index: A new speaker-centered aerodynamic metric for the evaluation of velopharyngeal function during speech. Perspectives of the ASHA Special Interest Groups, 6(2), 368-374, 2021.
- Zajac, D.J., Powell, J., & McQuillan, M. Development and resolution of nasal fricatives in a child with repaired bilateral cleft lip and palate: A case report. Perspectives of the ASHA Special Interest Groups, 6(4):743-754, 2021.
- Zajac, D.J., Whitt, H., Baylis, A., Tourian, M., & Garcia, K. Alveolar backing in 3-year-old children with and without repaired cleft palate: preliminary findings related to cleft type and history of otitis media. Perspectives of the ASHA Special Interest Groups, 27:1-11, 2021.
- Lathrop-Marshall, H., Keyser, M. M. B., Jhingree, S., Giduz, N., Bocklage, C., Couldwell, S… Zajac, D.J., & Jacox, L.A. Orthognathic speech pathology: impacts of Class III malocclusion on speech. European Journal of Orthodontics, September 25, 2021.
- Keyser, M. M., Lathrop, H., Jhingree, S., Giduz, N., Bocklage, C., Couldwell, S., Oliver, S., Moss, K., Frazier-Bowers, S., Phillips, C., Turvey, T., Blakey, G., White, R., Mielke, J., Zajac, D.J., & Jacox, L. Impact of skeletal anterior open bite malocclusion on speech. FACE: J Am Soc of Maxillofacial Surgeons, 2022.
- Jhingree, S., Xie, Y., Bocklage, C., Giduz, N., Moss, K., Zajac, D.J., & Jacox, L. (2022). Validating spectral moment analysis as a quantitative measure of speech distortions in speakers with Class III malocclusions. Perspectives of the ASHA Special Interest Groups, E Pub, May 5, 2022.
Books and Chapters
- Zajac, D.J. Speech Aerometry. In M.J. Ball (ed.), Manual of Phonetics, pp. 264-281. Routledge, 2021.
- Vallino, L.D., Ruscello, D.M., & Zajac, D.J. Cleft Palate Speech and Resonance: An Audio and Video Resource. San Diego, CA: Plural Publishing, 2019.
- Zajac, D.J. Airflow Measurement. In Jack S. Damico & Martin J. Ball (eds.), The SAGE Encyclopedia of Human Communication Sciences and Disorders, pp. 76-78, Thousand Oaks, CA: SAGE Publications, Inc., 2019.
- Zajac, D.J. Evaluation and Management of Speech Disorders for the Patient with Cleft Palate, in R.J. Fonseca, T. Turvey, B.J. Costello, R.L. Ruiz (eds.), Oral and Maxillofacial Surgery, Third Edition, Volume III, pp. 568-582. St. Louis: Elsevier, 2018.
- Zajac, D.J., & Vallino, L.D. Evaluation and Management of Cleft Lip and Palate: A Developmental Perspective. San Diego, CA: Plural Publishing, 2017.
- Zajac, D.J. Velopharyngeal Function in Speech Production: Some Developmental and Structural Considerations, in M.A. Redford (ed.), Handbook of Speech Production, pp. 109-130. Malden, MA: Blackwell, 2015.
- Zajac, D.J. Speech Aerodynamics, in A. Kummer (ed.), Cleft Palate and Craniofacial Anomalies: Effect on Speech and Resonance, 3nd Edition, pp. 435-467. San Diego: Singular Publishing, 2013.
- Zajac, D.J. Evaluation and Management of Speech Disorders for the Patient with Cleft Palate, in R.J. Fonseca, R. Marciani, T. Turvey (eds.), Oral and Maxillofacial Surgery, Second Edition, Volume III, pp. 791-805. St. Louis: Elsevier, 2009.
- Zajac, D.J., Warren, D. W., & Hinton, V.A. Aerodynamic Assessment of Motor Speech Disorders, in M. R. McNeil (ed.), Clinical Management of Sensorimotor Speech Disorders, pp. 64-79. New York: Thieme, 2009.
- Zajac, D.J. Speech Aerodynamics, in A. Kummer (ed.), Cleft Palate and Craniofacial Anomalies: Effect on Speech and Resonance, 2nd Edition, pp. 415-445. San Diego: Singular Publishing, 2007.
- Sloan, G., & Zajac, D.J. Velopharyngeal Dysfunction, in S. Mathes (ed.), Plastic Surgery, 2nd Edition, Volume 4, Pediatric Plastic Surgery, pp. 311-337. Philadelphia: Saunders Elsevier, 2006.
- Zajac, D.J. Speech Aerodynamics of Cleft Palate, in A. Kummer (ed.), Cleft Palate and Craniofacial Anomalies: Effect on Speech and Resonance, pp. 327-354. San Diego: Singular Publishing, 2000.
- Zajac, D.J., & Yates, C. Speech Aerodynamics, in M. Ball and C. Code (eds.), Instrumental Clinical Phonetics, pp. 87-118. London: Whurr, 1997.