This study investigates the role of minimal contrast in phonetics and
phonology. Two sounds are minimally contrastive when they differ in just
one property. The main findings are that (i) minimal contrast can influence
phonetic effects and (ii) phonological processes may single out minimally
contrastive elements. An experiment tests the influence of minimal length
contrast on the phonetic voicing effect, a pattern by which vowels are
longer before voiced than before voiceless obstruents, in Lithuanian. In
Lithuanian, only high and low vowels are minimally contrastive for length.
The results indicate the voicing effect is more limited for those vowels
that are minimally contrastive for length, showing a phonetic pattern
sensitive to minimal contrast. Therefore, it is argued that the
phonological representation must include information about minimal
contrast. Minimal contrast is formalized with a contrast-coindexing
function, which applies to minimally contrastive segments capable of
distinguishing pairs of words.
Contrast-coindexing predicts that minimal contrast might also be active in
the phonology. Evidence for this comes from vowel height harmony in Lena
Asturian, where only vowels minimally contrastive for height can trigger
harmony. The typology of vowel harmony from several varieties related to
Lena further supports the active role of minimal contrast.