A comprehensive analysis of age and gender effects in European Portuguese oral vowels

Abstract

The knowledge about the age effects in speech acoustics is still disperse and incomplete. This study extends the analyses of the effects of age and gender on acoustics of European Portuguese (EP) oral vowels, in order to complement initial studies with limited sets of acoustic parameters, and to further investigate unclear or inconsistent results. A database of EP vowels produced by a group of 113 adults, aged between 35 and 97, was used. Duration, fundamental frequency (f0), formant frequencies (F1 to F3), and a selection of vowel space metrics (F1 and F2 range ratios, vowel articulation index [VAI] and formant centralization ratio [FCR]) were analyzed. To avoid the arguable division into age groups, the analyses considered age as a continuous variable. The most relevant age-related results included: vowel duration increase in both genders; a general tendency to formant frequencies decrease for females; changes that were consistent with vowel centralization for males, confirmed by the vowel space acoustic indexes; and no evidence of F3 decrease with age, in both genders. This study has contributed to knowledge on aging speech, providing new information for an additional language. The results corroborated that acoustic characteristics of speech change with age and present different patterns between genders.