Positional Neutralization - Linguistics - University of California ...

which it is a priori impossible to determine, presumably for linguist and learner alike,
which grammatical mechanism is responsible for generating such a pattern is troubling.
This is not, however, the only instance in which the line between the two types of
reduction systems becomes blurred.
Firstly, contrast-enhancing UVR is not so simple in its implementation as it might
seem. In the cases of Standard Italian, Belorussian, the pretonic syllables of Brazilian
Portuguese and the immediate pretonic syllable of Russian (introduced below), the low
vowel, designated as the diagnostic for system type, was said to be peripheral, and was
transcribed [a]. This, however, turns out to be a substantial idealization of the phonetic
facts.
In Standard Italian, for example, where all unstressed syllables witness a merger
of the tense and lax mid vowels, the vowel transcribed [a] is in fact substantially raised in
most unstressed syllables. Farnetani and Vayra (1991) provide experimental evidence
showing that F1 values for the unstressed vowels of two (northern) speakers of Standard
Italian are on average decreased by 28% (974 Hz vs. 700 Hz) for one speaker and 18%
(669 Hz vs. 548 Hz) for another. Furthermore, this experiment found a high degree of
correlation between vowel duration and F1 values (for the two speakers r(133) = 0.783
and r(130) = 0.774 respectively. Rather than implementing a maximally (or even steadily)
peripheral vowel, then, here the realization of /a/ is a function of its duration. The reason
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