Truncation and compression
Phonetic realisation effects, said to be language-specific
The same intonational morpheme is realised differently under time pressure (e.g. on a word like hat which has a short vowel and is surrounded by voiceless consonants).
Speakers can compress: the contour falls or rises faster, or they can truncate: the contour remains unfinished
NB: speakers have a third option - instead of adjusting the contour, they can lengthen the short word (e.g. in Portugese; S. Frota, pc)