Compression and truncation: The case of Seoul Korean accentual phrase

Abstract

Compression and truncation are two general strategies adopted by languages in realizing tonal melodies in the face of time pressure. Compression involves adjustment of the phonetic details of tone realization to fit a tone sequence in the time available, while truncation involves deletion of a phonological tone, reducing a melody to fit the segmental material with which it must be associated. Seoul Korean appears to show truncation of tones in response to time pressure resulting from fast speech rate: the Accentual Phrase (AP) is canonically marked by a rise-fall-rise melody (LHLH), but at fast speech rates, APs can be realized with a rising F0 contour. Categorical tone deletion conditioned by speech rate would be theoretically significant because it would imply that a phonological operation can be conditioned by utterance-specific phonetic detail. However, analysis of the realization of the AP melody across a range of speech rates provides evidence that the apparent deletion of tones is actually the end result of compressing the final HLH sequence into such a short interval that the low tone is completely undershot and the two high tones are effectively merged. This analysis illustrates the general point that it is not possible to determine what phonological representation gave rise to a particular phonetic form without explicit analysis of the process of phonetic implementation.