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Gillespie, Amanda I (2013) EFFECTS OF HYPER- AND HYPOCAPNIA ON PHONATORY LARYNGEAL RESISTANCE. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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The larynx has a challenging dual role in the simultaneous regulation of gas flow into and out of the lungs while also establishing resistance required for vocal fold vibration in voiced communication. Particular challenges may arise when the larynx is required to alter upper airway resistance to meet respiratory demands in a way that conflicts with requirements for voice production. Little if anything is known about reciprocal relations between these functions, particularly under conditions of respiratory abnormality that affect large sectors of the population- an estimated 25% of the US population who experience respiratory abnormalities and also relies on the larynx for voiced communication.
In order to address this gap, the current study investigated two specific aims in a single within-subjects experiment: Specific Aim 1 (SA1) assessed spontaneous fluctuations in phonatory laryngeal resistance during states of (a) induced hypocapnia (low arterial carbon dioxide) and (b) induced hypercapnia (high arterial carbon dioxide), in comparison to a eupneic control condition and Specific Aim 2 (SA2) investigated the reciprocal effects of laryngeal resistance modulations on respiratory homeostasis.
Results of the first aim demonstrated that phonatory laryngeal resistance remained stable and did not significantly change despite manipulations of inspired gas concentrations causing significant increases and decreases in carbon dioxide (CO2) levels. For the second aim, results showed that phonation significantly increased levels of end-tidal carbon dioxide (PetCO2) in all experimental conditions, compared to PetCO2 levels during rest breathing. Findings provide support for a theory of voice motor control suggesting that phonatory laryngeal resistance may be an essential, relatively immutable control parameter in phonation (except perhaps under extreme conditions not tested herein), and provides data on the influence of phonation on respiration. The current work sets the foundation for future studies of laryngeal function during phonation in individuals with lower airway disease.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Gillespie, Amanda
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairVerdolini, Katherinekav25@pitt.eduKAV25
Atwood, Charlesatwoodcw@pitt.eduATWOODCW
Gartner-Schmidt, Jacquelinejgs@pitt.eduJGS
Shaiman, Susanshaiman@csd.pitt.eduSHAIMAN
Yaruss, J. Scottyaruss@pitt.eduYARUSS
Date: 24 May 2013
Date Type: Publication
Defense Date: 16 January 2013
Approval Date: 24 May 2013
Submission Date: 13 February 2013
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 139
Institution: University of Pittsburgh
Schools and Programs: School of Health and Rehabilitation Sciences > Communication Science and Disorders
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: voice, laryngeal resistance, homeostasis, hypercapnia, hypocapnia
Date Deposited: 24 May 2013 14:26
Last Modified: 15 Nov 2016 14:09


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