This study was intended to replicate and extend previous findings that (a) during fluent speech persons who stutter (PS) and those who do not (NS) differ in their vocal tract closing movements (L. Max, A. J. Caruso, & V. L. Gracco, 2003) and (b) ratios relating lip and tongue speed to jaw speed increase with stuttering severity (M. D. McClean & C. R. Runyan, 2000). An electromagnetic system was used to record movements of the upper lip, lower lip, tongue, and jaw of 43 NS and 37 PS during productions of a nonsense phrase and a sentence. Measurement and analysis of movement speeds, durations, and ratios of lip and tongue speed to jaw speed were performed on fluent productions of a nonsense phrase and sentence. Statistical comparisons were made between PS with low and high stuttering severity levels (LPS and HPS) and NS. Significant variations across groups in movement speed and duration were observed, but the pattern of these effects was complex and did not replicate the results of the two earlier studies. In the nonsense phrase, significant reductions in lower lip closing duration, jaw closing duration, and jaw closing speed were seen in PS. In the sentence task, HPS showed elevated tongue opening and closing durations. For tongue opening in the sentence, LPS showed elevated speeds and HPS showed reduced speeds. The elevated speeds for LPS are interpreted as a contributing factor to speech disfluency, whereas the reduced speeds and increased durations in HPS are attributed to adaptive behavior intended to facilitate fluent speech. Significant group effects were not seen for the speed ratio measures. Results are discussed in relation to multivariate analyses intended to identify subgroups of PS.
References
-
Armson, J., & Stuart, A. (1998). Effect of extended exposure to frequency-altered feedback on stuttering during reading and monologue.Journal of Speech, Language, and Hearing Research, 41, 479–490. -
CarusoA.,AbbsJ., & GraccoV. (1988). Kinematic analysis of speech multiple movement coordination in stutterers.Brain, 111, 439–455. -
Gracco, V. L. (1994). Some organizational characteristics of speech movement control.Journal of Speech and Hearing Research, 37, 4–27. -
Kleinow, J., & Smith, A. (2000). Influences of length and syntactic complexity on the speech motor stability of the fluent speech of adults who stutter.Journal of Speech, Language, and Hearing Research, 43, 548–559. -
Max, L.,Caruso, A. J., & Gracco, V. L. (2003). Kinematic analysis of speech, orofacial speech, and finger movements in stuttering and nonstuttering adults.Journal of Speech, Language, and Hearing Research, 46, 215–232. -
McClean, M. D. (1997). Functional components of the motor system: An approach to understanding the mechanisms of speech disfluency.InW. Hulstijn, P. Van Lieshout, & H. Peters (Eds.), Speech production: Motor control, brain research and fluency disorders (pp. 99–118). Amsterdam: Elsevier. -
McClean, M. D.,Kroll, R. M., & Loftus, N. S. (1990). Kinematic analysis of lip closure in stutterers’ fluent speech.Journal of Speech and Hearing Research, 33, 755–760. -
McClean, M. D.,Kroll, R. M., & Loftus, N. S. (1991). Correlation of stuttering severity and lip closure in stutterers’ fluent speech.InH. F. M.W. PetersHulstjin, & C. W. Starkweather (Eds.), Speech motor control and stuttering (pp. 117–122). Amersterdam: Elsevier Science. -
McClean, M. D., & Runyan, C. R. (2000). Variations in the relative speeds of orofacial structures with stuttering severity.Journal of Speech, Language, and Hearing Research, 43, 1524–1531. -
McClean, M. D., & Tasko, S. M. (2003). Association of orofacial muscle activity and movement during changes in speech rate and intensity.Journal of Speech, Language, and Hearing Research, 46, 1387–1400. -
Muma, J. R. (1993). The need for replication.Journal of Speech, Language, and Hearing Research, 36, 927–930. -
Riley, G. (1994). Stuttering Severity Instrument.: Austin, TX: Pro-Ed. -
Samar, V. J.,Metz, D. E., & Sacco, P. R. (1986). Changes in aerodynamic characteristics associated with therapy. Journal of Speech and Hearing Research, 29, 106–113. -
Smith, A., & Kleinow, J. (2000). Kinematic correlates of speaking rate changes in stuttering and normally fluent adults.Journal of Speech, Language, and Hearing Research, 43, 521–536. -
Story, R. S.,Alfonso, P. J., & Harris, K. S. (1996). Pre- and posttreatment comparison of the kinematics of the fluent speech of persons who stutter.Journal of Speech and Hearing Research, 39, 991–1005. -
Tasko, S. M., & Westbury, J. R. (2002). Defining and measuring speech movement events.Journal of Speech, Language, and Hearing Research, 45, 127–142. -
Tuller, B.,Shao, S., & Kelso, J. A. (1990). An evaluation of an alternating magnetic field device for monitoring tongue movements.Journal of the Acoustical Society of America, 88, 674–679. -
Westbury, J. R.,Lindstrom, M. J., & McClean, M. D. (2002). Tongue and lips without jaws: A comparison of methods for decoupling speech movements.Journal of Speech, Language, and Hearing Research, 45, 651–662. - Zimmermann G. (1980a). Articulatory dynamics of fluent speech utterances of stutterers and nonstutterers.Journal of Speech and Hearing Research, 23, 95–107.
- Zimmermann G. (1980b). Stuttering: A disorder of movement.Journal of Speech and Hearing Research, 23, 122–136.