In this paper we discuss the effects of tonal clash (or strict adjacency between two accents) on the phonetic realization of H* accents in Spanish. A preliminary analysis of the data shows that adjacency of two H* accents triggers a drastic temporal reorganization of the F0 gestures involved, resulting in anticipation of the first gesture and delay of the second. Specifically, in crowded tonal contexts we find that the start of the rise of the first H* accent occurs significantly earlier with respect to the syllable onset, as well as later in the second accent. Similarly, the two adjacent accented syllables are lengthened and their H* rise times and peak delays increase. Thus, the data reveals that F$ gestures are roughly timed to accented syllables, keeping a more or less floating relationship with the segmentals: both right and left-hand prosodic contexts (including clash situations) determine the alignment patterns of the valley and the peak. Finally, no significant differences were found on the F0 scaling in clash vs. non-clash environments.
Bibliographic reference. Prieto, Pilar / Shih, Chilin (1995): "Effects of tonal clash on downstepped h* accents in Spanish", In EUROSPEECH-1995, 1307-1310.