Title | Vocalization Subsystem Responses to a Temporarily Induced Unilateral Vocal Fold Paralysis. |
Publication Type | Journal Article |
Year of Publication | 2018 |
Authors | Croake DJ, Andreatta RD, Stemple J |
Journal | J Speech Lang Hear Res |
Volume | 61 |
Issue | 3 |
Pagination | 479-495 |
Date Published | 2018 03 15 |
ISSN | 1558-9102 |
Keywords | Acoustics, Adult, Air Movements, Biomechanical Phenomena, Female, Humans, Larynx, Lung, Male, Models, Biological, Multilevel Analysis, Phonation, Pressure, Reproducibility of Results, Respiration, Vocal Cord Paralysis, Voice, Young Adult |
Abstract | Purpose: The purpose of this study is to quantify the interactions of the 3 vocalization subsystems of respiration, phonation, and resonance before, during, and after a perturbation to the larynx (temporarily induced unilateral vocal fold paralysis) in 10 vocally healthy participants. Using dynamic systems theory as a guide, we hypothesized that data groupings would emerge revealing context-dependent patterns in the relationships of variables representing the 3 vocalization subsystems. We also hypothesized that group data would mask important individual variability important to understanding the relationships among the vocalization subsystems. Method: A perturbation paradigm was used to obtain respiratory kinematic, aerodynamic, and acoustic formant measures from 10 healthy participants (8 women, 2 men) with normal voices. Group and individual data were analyzed to provide a multilevel analysis of the data. A 3-dimensional state space model was constructed to demonstrate the interactive relationships among the 3 subsystems before, during, and after perturbation. Results: During perturbation, group data revealed that lung volume initiations and terminations were lower, with longer respiratory excursions; airflow rates increased while subglottic pressures were maintained. Acoustic formant measures indicated that the spacing between the upper formants decreased (F3-F5), whereas the spacing between F1 and F2 increased. State space modeling revealed the changing directionality and interactions among the 3 subsystems. Conclusions: Group data alone masked important variability necessary to understand the unique relationships among the 3 subsystems. Multilevel analysis permitted a richer understanding of the individual differences in phonatory regulation and permitted subgroup analysis. Dynamic systems theory may be a useful heuristic to model the interactive relationships among vocalization subsystems. Supplemental Material: https://doi.org/10.23641/asha.5913532. |
DOI | 10.1044/2017_JSLHR-S-17-0227 |
Alternate Journal | J. Speech Lang. Hear. Res. |
PubMed ID | 29486490 |