Towards a comprehensive investigation of factors relevant to peak alignment using a unit selection corpus

This paper aims to demonstrate the use of a unit selection corpus, the IMS German Festival synthesis system [1], in carrying out a comprehensive investigation of factors influencing specific aspects of the phonetic realization of tonal categories. The study restricts itself to the alignment of peaks in H*L pitch accents in German. First results confirm not only well-known effects of syllable structure, e.g., peaks occurring relatively early when there is a sonorant onset or relatively late when there is a sonorant in the coda, but also attest to the special status of the nuclear pitch accent vs. accents occurring earlier in the intonation phrase. Furthermore, instances of H*L in syllables directly at the phrase boundaries (initial or final) are shown to behave significantly differently from those that are located farther away. A similar effect is observed when another pitch accent follows the H*L peak in the very next syllable as opposed to a distance of two or more syllables. In these cases it also matters whether a low or high target is following (the peaks occur relatively later when followed by a L target). The results should have the benefit of both describing the specific characteristics of the voice providing the corpus (allowing a more detailed phonetic realization of tonal categories during the synthesis process) and offering general insights into which factors are relevant to the alignment of H*L peaks in German.