Communication Disorders Ph.D. Dissertations

Title

Whisper and Phonation: Aerodynamic Comparisons across Adduction and Loudness Levels

Date of Award

2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Communication Disorders/Speech-Language Pathology

First Advisor

Ronald Scherer (Advisor)

Second Advisor

Lewis Fulcher (Committee Member)

Third Advisor

Roger Colcord (Committee Member)

Fourth Advisor

Alexander Goberman (Committee Member)

Abstract

The purpose of the present project was to compare the aerodynamics of whisper and phonation. The novel aspect was to have subjects produce both whisper and phonation for nine different conditions, three qualities relative to levels of adduction (breathy, normal, and pressed) and three levels of loudness (soft, medium, and loud). The study reports subglottal pressure (Ps), airflow (F), and laryngeal flow resistance (Rf, the ratio Ps/F) for all conditions. Three males and five females between 20 and 30 years of age whispered and phonated smooth syllable strings of /baep/. This resulted in 18 treatment combinations (i.e., 3 adductions x 3 loudness levels x 2 genders). A regression analysis was performed using a Proc-mixed procedure with SAS statistical software.

Results relative to laryngeal source (phonation vs. whisper): Ps was not significantly different between whisper and phonation (except for the breathy soft condition in females, where Ps was greater in phonation). Flow typically was higher for whisper than phonation (except for soft conditions, where flow was about the same). Rf tended to be greater for phonation than for whisper for females, but not for males (where Rf was about the same between phonation and whisper).

Results relative to loudness: Ps increased with loudness (soft, medium, loud) at each of the three adduction levels for both phonation and whisper. Flow tended to increase with loudness in whisper at each level of adduction, but flow results were varied for phonation. In phonation, Rf increased with loudness at each level of adduction, but there was no general pattern for whisper (being relatively constant across loudness levels for each gender).

Results relative to adduction: Ps increased from normal to breathy to pressed at each level of loudness for phonation, and similarly for whisper (except Ps was about the same for normal and breathy whisper productions). Breathy adduction had the greatest flow at each level of loudness for both phonation and whisper. Flow was about the same in both phonation and whisper for normal and pressed productions. Rf increased from breathy to normal to pressed at each level of loudness (although for whisper, Rf was similar for breathy and normal productions).

Results relative to gender: Ps tended to be higher in males than females for all nine conditions for phonation and whisper. Males tended to have greater flow for phonation but lower flow for whisper for all conditions. Males produced greater Rf values for whisper across adduction, but lower Rf values (relatively small differences, however) for phonation across adduction levels.

While there are some clear and understandable trends for the aerodynamic measures relative to changes in loudness and adduction for whisper, phonation, and gender, the results are best taken as testable hypotheses for future research.

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