On Vowels : Spectral Features, Related Aspects of Production and Sociophonetic Dimensions

Sammanfattning: The first and major part of this thesis deals with spectral features of vowels and with the distinction of phonetic information from personal and transmittal information also conveyed to listeners by speech sounds. The results of perceptual experiments with synthetic vowels whose fundamental and first formant were varied in frequency suggested that the smaller tonotopical distances between formants (< 6 Bark) are invariant in phonetically idenctical vowels produced by male and female speakers of several languages. It is further investigated how partials are resolved in the process of timbre perception. Previous experiments by other researchers suggest an effective bandwidth close to three Bark. In similar experiments, though using different stimuli, this result could not be replicated. A re-analysis of some other experimental results gave, among other details, effective bandwidths roughly proportional to frequency in the range below 600 Hz. Due to contextual effects, the general validity of this result is in question. The non-uniform sex-differences in formant frequencies are shown mainly to be consequences of an anatomical development in accord with the perceptual condition of invariant phonetic qualities.The second part of the thesis, Vocalism in Eastern Central Bavarian, represents a case study of the realization of sociophonetic dimensions in speech. In the chosen group of dialects some phonological rules lead to a richly shadowed vowel system. The application of these rules is investigated with respect to dialectal, sociolectal, speaker age, and speech tempo variation.