The effect of local speaking rate on the perception of quantity in Estonian

The Estonian language with its elaborate system of contrasts in quantity, whose essentials are described in the paper, is used to investigate human perception of distinctive contrasts in the duration of vowels, consonants and larger units. In the experiments reported, the speaking rate of a preceding or following syllable was manipulated in addition to that of a target V, C or VC sequence that carried a quantity distinction in disyllabic words. The results confirmed that the second syllable in such words, in particular the duration of its vowel, serves as a reference, but they showed segments of additional syllables to contribute in the same direction. The results provided no support for ascribing quantity to any larger units than phonetic segments. Speech rate effects of similar magnitude have been observed in Japanese, while effects of the same kind were found to be smaller in Dutch. These differences may be linked with the functions durational contrasts have in the different languages. It appears that listeners have to adapt more fully to variations in the local speaking rate when there are no additional cues and the functional load of quantity distinctions is high.