This paper investigates the influence of duration and F0 interval of the utterance-final F0 contour on the perception of sentence modality, i.e. declarative or interrogative sentence. An utterancefinal rising contour with a constant F0 interval of 2 semitones or more and a voicing duration of at least 50 ms leads to unanimously identified interrogative modality. Even at durations of 20 and 30 ms a significant number of listeners is able to consistently identify sentence modality. F0 interval seems to better predict perceived sentence modality than F0 slope.
Bibliographic reference. Peters, Benno / Pfitzinger, Hartmut R. (2008): "Duration and F0 interval of utterance-final intonation contours in the perception of German sentence modality", In INTERSPEECH-2008, 65-68.