Compensatory lengthening: Phonetics, phonology, diachrony

The term compensatory lengthening (CL) refers to a set of phonological phenomena wherein the disappearance of one element of a representation is accompanied by a corresponding lengthening of another element. This study focuses on descriptive and formal similarities and divergences between CL of vowels triggered by consonant and by vowel loss.;This thesis argues that to account for the full range of existing compensatory phenomena as well as for the absence of certain logically possible outcomes of CL, it is necessary to distinguish synchronic and diachronic aspects of CL. On the basis of a typological survey of languages possessing CL, it is shown that CL through consonant and vowel loss are similar diachronically: both arise through phonologization of inherent duration of vowels and neither involves any transfer of length or weight. Rather, intrinsic phonetic vowel durations in both types are reinterpreted as phonologically significant upon a change in the conditioning environment or syllable structure. To account for the diachronic source of CL, a phonologization model is developed based on a listener-oriented view of sound change.;Though similar diachronically, CL through consonant and through vowel loss function differently in synchronic grammars. Because of this split, purely phonological accounts, such as mora conservation, are inadequate to predict the full typology of CL. It is proposed that the nature of the split is due to a difference in the relationship between trigger and target for the two types of CL. Consonant loss in CVC CL is usually transparent, since it is always segmentally conditioned, assuring synchronic recoverability of its trigger and permitting synchronic CVC CL alternations to be modeled as moraic conservation within the syllable. By contrast, CVCV CL is rarely segmentally conditioned. In most cases the trigger of CVCV CL is not recoverable synchronically, and thus vowel length alternations become lexicalized or morphologized and do not result in synchronic compensatory processes. In those few cases where the loss of the trigger of CVCV CL is segmentally conditioned and thus synchronically recoverable, CVCV CL alternations remain transparent and formally comparable to CVC CL alternations.