Acoustic and perceptual analysis of modal and falsetto registers in females with dysphonia
Acoustic and Perceptual Analysis of Modal and Falsetto Registers in Females with Dysphonia
Nicole Yee-key Li
for the degree of Master of Philosophy at The University of Hong Kong in January 2003
Modal and falsetto registers are the basic vocal qualities used in female speaking voices. The purpose of this study was to identify the frequency at which modal register changed to falsetto register and the frequency range of each modal and falsetto register produced under three loudness levels: soft, comfortable and loud phonations.
Fifteen dysphonic and 15 non-dysphonic females were assessed on their ability to produce tone series from the lowest to the highest frequency at soft, comfortable and loud phonations. Fourteen listeners served as judges to identify the first production of falsetto voice in each tone series. The first falsetto tone represented the frequency at which the modal-falsetto register change occurred perceptually.
The change from modal to falsetto register in the tone series occurred between F4 (349.23 Hz) and B4 (493.88 Hz) in the dysphonic group and between 0#4 (415.30 Hz) andA#4 (466.16 Hz) in the non-dysphonic group among the three loudness levels. The dysphonic group demonstrated the modal-falsetto register change at a significantly lower frequency than that of the non-dysphonic group in the soft and comfortable phonations. Both subject groups also showed that the modal-falsetto register change occurred at a significantly lower frequency when soft phonation was used.
For the frequency range of the modal register, the dysphonic group showed reduced frequency range in the soft and the comfortable phonations when compared to the non-dysphonic group. However, no significant difference was found in the production of the frequency range of the modal register between the dysphonic and the non-dysphonic groups when loud phonation was used. For the frequency range of the falsetto register, the dysphonic group showed reduced ability compared to the non-dysphonic group when loud phonation was used.
The use of different loudness phonations affected the production of the modal and falsetto registers. Both subject groups showed the most restricted frequency range of the modal register when they phonated softly. When soft phonation was used, the frequency at which the modal-falsetto register change occurred and the maximum frequency produced were significantly lower than those of comfortable and loud phonations. Therefore, the falsetto voice essentially shifted its region to a relatively lower frequency region in soft phonation.
The present study showed that dysphonia affected the production of falsetto register. Future works can be directed to the physiological investigation of the production of the falsetto register in relationship to different vocal pathologies.
School:The University of Hong Kong
School Location:China - Hong Kong SAR
Source Type:Master's Thesis
Keywords:vocal registers voice disorders speech physiological aspects
Date of Publication:01/01/2003