1992 Volume 4 Issue 2 Pages 95-104
In order to evaluate the phonatory function causing by senescence of the larynx, normal adult subjects (52 males and 45 females) were examined the aerodynamic aspects and acoustic analysis for their sustained vowel phonation, and also we measured their pulmonary function test at the same time. The parameters for phonatory function were applied the Maximum sustained phonation time (M.P.T), Mean flow rate (M.F.R), Air flow rate (A.F.R) and Vocal velocity index (V.V.I) by the use of PS-77 phonatory equipment. Acoustic analysis for their voices were investigated the fundamental frequency and PPQ and APQ using the Voice Evaluation System SH-10, made by the RION Co.. In some cases, we measured the subglottic pressure to obtained the laryngeal resistance and efficiency. In this study, chronologically, subjects were classified into three age groups such 20-45, 45-65, and more than 65 years old, and each age groups divided the two groups by the values of VVI less than 50, and of more than 50.
With increasing ages, they revealed a tendency of decrease of MPT values, and increase the MFR and AFR with phonatory tests, and also, decreasing of VC and FEV1 with pulmonary test. These data showed a significant difference between the young age groups and the groups more 65 years old. In acoustic analysis, fundamental frequencies in old persons showed to become more higher pitch in males, but lower in females voices. In older female subjects with VVI more than 50, weakness and lower pitch of voices were caused by reduction of subglottic pressure and glottal resistance at phonation.
Results were summarized as follows :
(1) Over 65 years old subjects may have a tendency to the hypotensive mode of phonation and closely be related to the reduced pulmonary power.
(2) Senescent voices were become the lower pitch and weakness of voices in female, and the higher pitch in males. This might be affected with reduced subglottic pressure and pulmonary power for phonatory modality such as degenerative changes of laryngeal and pulmonary muscles.
(3) Increasing values of PPQ, and APQ by aging, more detailed laryngeal senescence information may be obtained from the analysis for air flow fluctuation during phonation, and pitch perturbations and amplitude modulations for their voice.
