Acoustic Characteristics of Stop Consonants in Normal Elderly
Changes in speech production in normal elderly might be subtle and gradual. Therefore, an acoustic analysis is appropriate to identify the effect of aging on speech. For this purpose, this study examined four speech parameters; voice onset time (VOT) VOT range, of following vowel( and difference in two age groups, old (mean age 74.57 yrs. and young (m: 27.43 yrs. The results show that compared to the older group the younger demonstrated significantly shorter VOTs in lenis and longer in aspirated stop. VOT ranges were relatively broad and consequently overlapped between the phonation types (e.g. lenis, fortis, aspirated) The values in the older group which are an integral parameter with VOT were lower compared with the young group. The differences in the old female group were significantly narrower than the young female group, therefore, clear distinction became difficult. In conclusion, contrast in temporal information was obscured, and the domain of glottal information was diminished on stop consonants in Korean elderly. The findings suggest that central/peripheral changes by aging could lead to a deficit in coordination between phonation and articulation.