|
The goal of this study was to evaluate invariance vs. variability in both articulation and acoustics of speech production units. To keep interaction of controlled variables manageable, only a very simple subrange of speech productions was studied. Three different vowel qualities and six different consonants were examined in a VCV sequence embedded in an utterance. Beside coarticulation vocal effort was a further factor of perturbation occuring in natural speech. The set of consonants comprised various modes of articulation (stop, fricative, nasal, lateral) all produced at virtually the same place of articulation, viz. (post-) alveolar. The range of vowel environments /i:/, /e:/, /a:/ was selected for differences in height, in order to vary coarticulatory effects between the segments. Utterances were produced at two different volume levels, viz. normal and loud speech. Experiments by others have demonstrated that higher speech volume is not simply realized as a raised sound pressure level or as raised intensity. For loud speech a number of different correlates were observed, as raised subglottal pressure (see Ladefoged/McKinney 1963), raised fundamental frequency, raised first formant, and change of segmental durations (e.g. Traunmüller/Eriksson 2000). Furthermore an effect on jaw height was observed in vowels, which is that in vowel production in loud speech the jaw has a lower position. In earlier studies results have been presented for either articulatory (Schulman 1989) or acoustic changes (Traunmüller/Eriksson 2000) associated with higher volume. The present study examines effects of higher volume level on vowels as well as on consonants, in the articulatory as well as the acoustic channel. Data from six German speakers (5 male, 1 female) were recorded and analyzed. In the 266 articulatory channel jaw and tongue-tip movements were analyzed, in the acoustic domain segmental characteristics as formants, duration, intensity and fundamental frequency. The main results can be described as follows: - Jaw height in ...
|
