Communication Disorders Ph.D. Dissertations


The Influence of Stress on the Voice

Date of Award


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Communication Disorders

First Advisor

Ronald Scherer (Advisor)

Second Advisor

Michael Ellison (Committee Member)

Third Advisor

Jason Whitfield (Committee Member)

Fourth Advisor

Casey Cromwell (Committee Member)

Fifth Advisor

Charles Hughes (Committee Member)


Although stress has been frequently attributed to voice disorder development and progression, little work has been done to determine the role of activation of the two major stress systems [the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis (HPA)] on changes in voice production parameters.

Nineteen healthy female participants (median age: 18; range: 18 to 23) were subjected to the Trier Social Stress Test protocol. Voice production parameters (average airflow, estimated subglottal pressure, laryngeal airflow resistance, open quotient from the EGG signal, speaking fundamental frequency, and percent of syllables produced in vocal fry) were measured at seven measurement time points (2 before the stressor, 1 after an anticipatory period, and 4 after the stressor). Participants rated their levels of stress and nine emotions and provided saliva samples at each measurement time. Salivary cortisol and salivary alpha-amylase were measured from the saliva samples.

Ten of the 19 participants experienced a minimum 2.5 nmol/l increase in salivary cortisol levels from before the stressor to after the stressor, indicating that they had HPA axis activation. There were no significant changes in aerodynamic or electroglottographic measures over the seven measurement time points. There was a significant increase in speaking fundamental frequency before the stressor and a reduction in fundamental frequency after the stressor. Estimated subglottal pressure and laryngeal airflow resistance measures were significantly higher in participants who did not experience an HPA axis response.