Positional Neutralization - Linguistics - University of California ...

points out the case of Luganda (Hyman and Katamba 1990, 1993), in which
compensatory lengthening caused by glide formation fails to apply where it would result
in a word-final long vowel. It is not clear how avoidance of final stress or metrical
invisibility of any kind could be invoked here, since Luganda is not generally analyzed as
having a stress, final or otherwise (see Hyman and Katamba 1993 specifically for an
overview and analysis matters concerning tone and accent in Luganda).
It is Buckley's thesis, instead, that in addition to constraints mandating avoidance
of stress on final syllables, languages have a more general tendency simply to avoid final
long vowels. It is this tendency which motivates both the failure of Iambic Lengthening
word-finally and a variety of other processes. Buckley attributes this tendency to "final
lengthening at the phonetic level" (183). If a language lengthens vowels finally (in some
prosodic constituents at least), this could result in the contrast between underlyingly long
and phonetically-lengthened short vowels becoming difficult to perceive, and thus
potentially subject to reanalysis and the collapse of the contrast.
Certainly final lengthening could have the effect of making the contrast between
long and short difficult to perceive, especially if other phonetic properties of final
syllables identified here were simultaneously weakening the perceptibility of the latter
parts of any vowels being realized there, such that both long and short vowels would
sound like a lengthened vowel that fades away toward the end. That the vowels merge
265