This thesis contains four manuscripts examining the respiratory mechanics of normal and stuttering speech. The first study (J.Appl.Physiol. 75 (2):696-703, 1993) examined lung volume (V scL) during stutterers' relatively fluent speech. We showed that stutterers used the V scL extremes. This suggested that stutterers recruited their respiratory muscles in a different manner than normals to maintain subglottic pressure (Psg). We therefore investigated respiratory muscle recruitment patterns in normals and stutterers. In the second study, (submitted to J.A.P.), we modified the Campbell pressure volume diagram by the addition of abdominal pressure (Pab) and by the use of a surrogate relaxation curve. The addition of Pab allowed us to differentiate between diaphragmatic and non diaphragmatic inspiratory muscles and to quantify expiratory muscle recruitment. The surrogate curve provided a good approximation of the true relaxation curve (non significant difference between surrogate and true relaxation curves: P $>$.10). The third study (submitted to J.A.P.) used the modified diagram to examine respiratory muscle recruitment patterns, instantaneous Psg, voluntary hyperinflation and intrinsic positive end-expiratory pressures (PEEPi) during normal and stuttering speech. Stutterers used consistent muscle recruitment patterns and consistent V scL but Psg was not as well controlled as in normals. Because a lack of control of Psg could have an immediate effect on the glottis, particularly at high or low V scL, we measured instantaneous Psg and flow in the final study (to be submitted to J.A.P.) to give us instantaneous glottal resistance. In this study we were able to plot a 'family' of glottal resistances that covered normal speech. This provided a normal envelope of resistances. When stutterers were fluent they remained within both the flow and Psg limits set by the normals' envelope. When they were fluent both Psg and flow extended beyond the normals' envelope. We conclude
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.40369 |
| Date | January 1996 |
| Creators | Johnston, Sharon J. |
| Contributors | Macklem, P. T. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (School of Physical and Occupational Therapy.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001530437, proquestno: NN19734, Theses scanned by UMI/ProQuest. |
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