Kris Tjaden, PhD

Professor and Associate Chair

  • Administrative office: 810 Clemens, North Campus
  • Research Office: 126 Cary Hall
  • Office Phone: 716.829.5564
  • Email:

Current Work:

Dr. Tjaden's Motor Speech Disorders Laboratory is located in 108/110 Cary Hall. The lab conducts research investigating the acoustic bases of reduced intelligibility and naturalness in dysarthria secondary to neurodegenerative disease such as Parkinson's disease and Multiple Sclerosis. One line of research aims to specify which therapeutic techniques for dysarthria yield improvements in speech intelligibility and naturalness - and the underlying supralaryngeal and prosodic adjustments responsible for those improvements. Additional studies are investigating the relationship between neuropsychological function and speech motor control characteristics in Multiple Sclerosis. We are also conducting studies, in collaboration with Dr. Alex Kain at the Center for Spoken Language Understanding (CSLU) at Oregon Health Sciences University, that aim to develop an acoustic model of intelligibility in dysarthria. The lab is presently funded by NIH-NIDCD R01DC004689 (PI; Tjaden).

Education / Training:

  • PhD, University of Wisconsin-Madison, 1995, Communicative Disorders & Sciences
  • MA, University of Minnesota, 1992, Speech-Language and Hearing Sciences
  • BA, Luther College, 1990, Psychology

Employment / Professional Experience:

  • Associate Dean for Faculty Affairs, College of Arts and Sciences, University at Buffalo, 2017-present
  • University at Buffalo, Professor, 2009-present
  • University at Buffalo, Associate Professor, 2002-2009
  • University at Buffalo, Assistant Professor, 1998-2002
  • San Diego State University, Assistant Professor, 1996-1998

Professional Honors/ Advisory and Editorial Boards:

  • Journal of Speech, Language and Hearing Research Speech Editor’s Award, 2005
  • Associate Editor for Speech, Journal of Speech Language and Hearing Research, 2005-2007
  • Acoustical Society of America, Member
  • American Speech, Language, and Hearing Association, Member
  • International Association of Logopaedics and Phoniatrics, Member
  • Certificate of Clinical Competence, American Speech-Language Hearing Association

Selected recent publications:

Tjaden, K., & Martel-Sauvageau, V. (2017). Vocalic transitions as markers of speech acoustic changes with STN-DBS in Parkinson’s Disease. Journal of Communication Disorders, 70, 1-11.

Tjaden, K., & Martel-Sauvageau, V. (2017). Consonant Acoustics in Parkinson’s Disease and Multiple Sclerosis: Comparison of Clear and Loud Speaking Conditions.  American Journal of Speech Language Pathology, 26, 569-582.

Kuo, C., Tjaden, K. (2016). Acoustic variation during passage reading for speakers with dysarthria and healthy controls. Journal of communication disorders, 62, 30-34.

Lam., J., & Tjaden, K. (2016). Clear speech variants: An acoustic study in Parkinson’s disease. Journal of Speech, Language, and Hearing Research, 59. 631-646.

Tjaden, K., Lam., J. & Feenaughty, L. (2015). Contemporary Issues in Dysarthria. In R. Bahr, & E. Silliman, (Eds). Handbook of Communication Disorders. (pp. 160-170). Oxford, UK: Routledge.

Stipancic, K. L., Tjaden, K., & Wilding, G. (2015). Comparison of Intelligibility Measures for Adults with Parkinson's Disease, Multiple Sclerosis and Healthy Controls. Journal of Speech, Language, and Hearing Research. doi: 10.1044/2015_jslhr-s-15-0271.

Kuo, C. Tjaden, K. & Sussman, J.E. (2014). Acoustic and Perceptual Correlates of Fast Speech Produced by Speakers with Parkinson’s Disease and Multiple Sclerosis. Journal of Communication Disorders. DOI: 10.1016/j.jcomdis.2014.09.002.

Feenaughty, L., Tjaden, K., & Sussman, J. (2014). Relationship between acoustic measures and judgments of intelligibility in Parkinson’s disease: A within – speaker approach. Clinical Linguistics and Phonetics, DOI: 10.3109/02699206.2014.921839.

Tjaden, K., Kain, A., & Lam, J. (2014). Hybridizing Conversational and Clear Speech to Investigate the Source of Increased Intelligibility in Parkinson’s Disease. Journal of Speech, Language and Hearing Research, 57, 1191-1205.

Tjaden, K., Sussman, J. & Wilding, G. (2014). Impact of Clear, Loud and Slow Speech on Scaled Estimates of Intelligibility and Speech Severity in Parkinson’s Disease and Multiple Sclerosis. Journal of Speech, Language & Hearing Research, 57, 779-792.

Lam, J., & Tjaden, K. (2013). Acoustic-perceptual relationships in variants of clear speech. Folia Phoniatrica Logopaedica, 65(3), 148-153.

Lam, J., & Tjaden, K. (2013). Intelligibility of Clear Speech: Effect of Instruction. J Speech Lang Hear Res, 56(5), 1429-1440. doi: 10.1044/1092-4388(2013/12-0335.

Tjaden, K., Richards, E., Kuo, C., Wilding, G., & Sussman, J. (2013). Acoustic and Perceptual Consequences of Clear and Loud Speech. Folia Phoniatrica et Logopaedica, 65(4), 214-220.

Tjaden, K., Lam, J., & Wilding, G. (2013). Vowel Acoustics in Parkinson's Disease and Multiple Sclerosis: Comparison of Clear, Loud, and Slow Speaking Conditions. J Speech Lang Hear Res, 56(5), 1485-1502. doi: 10.1044/1092-4388(2013/12-0259).

Feenaughty, L. Tjaden, K., Benedict, R., & Weinstock-Guttman, B., & Benedict, R. (2013). Speech and pause characteristics in Multiple Sclerosis: Comparison of speakers with high and low neuropsychological test performance. Clinical Linguistics and Phonetics, 27, 134-151.

Lam, J., Tjaden, K., & Wilding, G. (2012). Acoustics of Clear Speech: Effect of Instruction. J Speech Lang Hear Res. doi: 10.1044/1092-4388(2012/11-0154)

Sussman, J. E., & Tjaden, K. (2012). Perceptual measures of speech from individuals with Parkinson's disease and multiple sclerosis: intelligibility and beyond. J Speech Lang Hear Res, 55(4), 1208-1219. doi: 10.1044/1092-4388(2011/11-0048.

Rodgers, J. D., Tjaden, K., Feenaughty, L., Weinstock-Guttman, B., & Benedict, R. H. (2012). Influence of Cognitive Function on Speech and Articulation Rate in Multiple Sclerosis. J Int Neuropsychol Soc, 1-8. doi: 10.1017/s1355617712001166

Tjaden, K. & Wilding, G. (2011). Speech and pause characteristics associated with rate reduction in
Parkinson’s disease and Multiple Sclerosis. Journal of Communication Disorders, 44, 655-665.

Tjaden, K. & Wilding, G. (2011). Effects of speaking rate on intelligibility in Parkinson’s disease. Clinical
Linguistics and Phonetics.

Tjaden, K. & Wilding, G. (2011). The Impact of Rate Reduction and Increased Loudness on Fundamental Frequency Characteristics in Dysarthria. Folia Phoniatrica et Logopaedica, 63, 178-186

Tjaden, K., Sussman, J., Liu, G., & Wilding, G. (2010). Long Term Average Spectral Measures of Dysarthria and their Relationship to Perceived Severity. Journal of Medical Speech-Language Pathology, 18, 125-132.


  • CDS 640: Motor Speech Disorders
  • CDS 575: Dysphagia
  • CDS 498: Undergraduate Research and Create Activity
  • CDS 499: Independent Study (Undergraduate)
  • CDS 600: Independent Study (Graduate)
  • CDS 700: Thesis Guidance


  • Editorial Board Member, Journal of Speech, Language and Hearing Research, 2016-2017
  • UB College of Arts and Sciences Appointments, Promotion and Tenure Committee, Member, 2016-2019
  • UB College of Arts and Sciences Dean Search Committee, Member, 2016
  • ASHA Grant Review and Reviewer Training Conference, Chair, 2015-2016
  • ASHA Lessons for Success Research Workshop, Steering Committee Member, 2014-2019
  • ASHA Research and Scientific Affairs Committee, Chair (2014-2016)
  • ASHA Science Advisory Board, Member (2014-2016)
  • Training in Grantsmanship for Rehabilitation Research (TIGRR) Workshop, Faculty Mentor (2013-present)
  • Member, Motor Function Speech Rehabilitation (MFSR) Study Section, NIH, 2010-2016
  • Ad-hoc Reviewer, Communicative Disorders Review Committee (CDRC) Study Section, NIDCD, 2002-present
  • Ad-hoc Reviewer and Chairperson for select meetings, Small Grant Program (R03), NIDCD, 1999-present
  • College of Arts and Sciences Graduate Fellowship Committee, 2010-2012
  • Topic Coordinator Motor Speech Disorders in Children and Adults, ASHA Convention 2010
  • ASHA Research and Scientific Affairs Committee, 2009-2012
  • Vice-chair and Member, University at Buffalo Social and Behavioral Sciences Institutional Review Board, 2003-2006
  • Acoustical Society of America, Stetson Scholarship Committee, Member, 2007-present
  • Editorial consultant: Communicative Disorders Review, Folia Phoniatrica et Logopaedica, Journal of the Acoustical Society of America, American Journal of Speech-Language Pathology: A Journal of Clinical Practice, Journal of Speech, Language and Hearing Research, Parkinson's Disease, Journal of Experimental Psychology: Human Perception and Performance